Seattle DPD - 2012 Seattle Building Code, Chapter 2 Definitions

2012 SEATTLE BUILDING CODE 19

CHAPTER 2

DEFINITIONS

SECTION 201GENERAL

201.1 Scope. Unless otherwise expressly stated, the follow-ing words and terms shall, for the purposes of this code, havethe meanings shown in this chapter.

201.2 Interchangeability. Words used in the present tenseinclude the future; words stated in the masculine genderinclude the feminine and neuter; the singular number includesthe plural and the plural, the singular.

201.3 Terms defined in other codes. Where terms are notdefined in this code and are defined in the InternationalEnergy Conservation Code, International Fuel Gas Code,International Fire Code, International Mechanical Code,International Existing Building Code or ((International))Uniform Plumbing Code, such terms shall have the meaningsascribed to them as in those codes.

201.4 Terms not defined. Where terms are not definedthrough the methods authorized by this section, such termsshall have ordinarily accepted meanings such as the contextimplies.

201.5 References to other codes. Whenever an International,National or Uniform Code is referenced in this code, it shallmean the Seattle edition of that code, including any localamendments. References to the “Building Code,” “FireCode,” “Mechanical Code” and “Plumbing Code” mean theSeattle editions of those codes.

SECTION 202DEFINITIONS

24-HOUR CARE. The actual time that a person is an occu-pant within a facility for the purpose of receiving care. Itshall not include a facility that is open for 24 hours and iscapable of providing care to someone visiting the facility dur-ing any segment of the 24 hours.

AAC MASONRY. Masonry made of autoclaved aeratedconcrete (AAC) units, manufactured without internal rein-forcement and bonded together using thin- or thick-bed mor-tar.

ACCESSIBLE. A site, building, facility or portion thereofthat complies with Chapter 11.

ACCESSIBLE MEANS OF EGRESS. A continuous andunobstructed way of egress travel from any accessible pointin a building or facility to a public way.

ACCESSIBLE ROUTE. A continuous, unobstructed paththat complies with Chapter 11.

ACCESSIBLE UNIT. A dwelling unit or sleeping unit thatcomplies with this code and the provisions for Accessibleunits in ICC A117.1.

ACCREDITATION BODY. An approved, third-party orga-nization that is independent of the grading and inspectionagencies, and the lumber mills, and that initially accredits andsubsequently monitors, on a continuing basis, the compe-tency and performance of a grading or inspection agencyrelated to carrying out specific tasks.

[A] ADDITION. An extension or increase in floor area orheight of a building or structure.

ADHERED MASONRY VENEER. Veneer secured andsupported through the adhesion of an approved bondingmaterial applied to an approved backing.

ADOBE CONSTRUCTION. Construction in which theexterior load-bearing and nonload-bearing walls and parti-tions are of unfired clay masonry units, and floors, roofs andinterior framing are wholly or partly of wood or otherapproved materials.

Adobe, stabilized. Unfired clay masonry units to whichadmixtures, such as emulsified asphalt, are added duringthe manufacturing process to limit the units’ water absorp-tion so as to increase their durability.

Adobe, unstabilized. Unfired clay masonry units that donot meet the definition of “Adobe, stabilized.”

[W] ADULT FAMILY HOME. A dwelling licensed by thestate of Washington in which a person or persons providepersonal care, special care, room and board to more than onebut not more than six adults who are not related by blood ormarriage to the person or persons providing the services.

[F] AEROSOL. A product that is dispensed from an aerosolcontainer by a propellant. Aerosol products shall be classifiedby means of the calculation of their chemical heats of com-bustion and shall be designated Level 1, Level 2 or Level 3.

Level 1 aerosol products. Those with a total chemicalheat of combustion that is less than or equal to 8,600 Brit-ish thermal units per pound (Btu/lb) (20 kJ/g).

Level 2 aerosol products. Those with a total chemicalheat of combustion that is greater than 8,600 Btu/lb (20 kJ/g), but less than or equal to 13,000 Btu/lb (30 kJ/g).

Level 3 aerosol products. Those with a total chemicalheat of combustion that is greater than 13,000 Btu/lb (30kJ/g).

[F] AEROSOL CONTAINER. A metal can or a glass orplastic bottle designed to dispense an aerosol. Metal cansshall be limited to a maximum size of 33.8 fluid ounces (1000ml). Glass or plastic bottles shall be limited to a maximumsize of 4 fluid ounces (118 ml).

AGGREGATE. In roofing, crushed stone, crushed slag orwater-worn gravel used for surfacing for roof coverings.

AGRICULTURAL BUILDING. A structure designed andconstructed to house farm implements, hay, grain, poultry,livestock or other horticultural products. This structure shall

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DEFINITIONS

20 2012 SEATTLE BUILDING CODE

not be a place of human habitation or a place of employmentwhere agricultural products are processed, treated or pack-aged, nor shall it be a place used by the public.

[W] AIR-IMPERMEABLE INSULATION. An insulationhaving an air permeance equal to or less than 0.02 L/s-m2 at75 Pa pressure differential tested in accordance with ASTME2178 or ASTM E283.

AIR-INFLATED STRUCTURE. A structure that uses air-pressurized membrane beams, arches or other elements toenclose space. Occupants of such a structure do not occupythe pressurized area used to support the structure.

AIR-SUPPORTED STRUCTURE. A structure wherein theshape of the structure is attained by air pressure and occu-pants of the structure are within the elevated pressure area.Air-supported structures are of two basic types:

Double skin. Similar to a single skin, but with an attachedliner that is separated from the outer skin and provides anairspace which serves for insulation, acoustic, aesthetic orsimilar purposes.

Single skin. Where there is only the single outer skin andthe air pressure is directly against that skin.

AISLE. An unenclosed exit access component that definesand provides a path of egress travel.

AISLE ACCESSWAY. That portion of an exit access thatleads to an aisle.

[F] ALARM NOTIFICATION APPLIANCE. A fire alarmsystem component such as a bell, horn, speaker, light or textdisplay that provides audible, tactile or visible outputs, or anycombination thereof.

[F] ALARM SIGNAL. A signal indicating an emergencyrequiring immediate action, such as a signal indicative of fire.

[F] ALARM VERIFICATION FEATURE. A feature ofautomatic fire detection and alarm systems to reduceunwanted alarms wherein smoke detectors report alarm con-ditions for a minimum period of time, or confirm alarm con-ditions within a given time period, after being automaticallyreset, in order to be accepted as a valid alarm-initiation sig-nal.

ALLOWABLE STRESS DESIGN. A method of propor-tioning structural members, such that elastically computedstresses produced in the members by nominal loads do notexceed specified allowable stresses (also called “workingstress design”).

[A] ALTERATION. Any construction or renovation to anexisting structure other than repair or addition.

ALTERNATING TREAD DEVICE. A device that has aseries of steps between 50 and 70 degrees (0.87 and 1.22 rad)from horizontal, usually attached to a center support rail in analternating manner so that the user does not have both feet onthe same level at the same time.

AMBULATORY CARE FACILITY. Buildings or portionsthereof used to provide medical, surgical, psychiatric, nursingor similar care on a less than 24-hour basis to persons who arerendered incapable of self-preservation by the services pro-vided.

ANCHOR. Metal rod, wire or strap that secures masonry toits structural support.

ANCHOR BUILDING. An exterior perimeter building of agroup other than H having direct access to a covered or openmall building but having required means of egress indepen-dent of the mall.

ANCHORED MASONRY VENEER. Veneer secured withapproved mechanical fasteners to an approved backing

ANNULAR SPACE. The opening around the penetratingitem.

[F] ANNUNCIATOR. A unit containing one or more indica-tor lamps, alphanumeric displays or other equivalent meansin which each indication provides status information about acircuit, condition or location.

[A] APPROVED. Acceptable to the building official orauthority having jurisdiction.

[A] APPROVED AGENCY. An established and recognizedagency regularly engaged in conducting tests or furnishinginspection services, when such agency has been approved.

APPROVED FABRICATOR. An established and qualifiedperson, firm or corporation approved by the building officialpursuant to Chapter 17 of this code.

APPROVED SOURCE. An independent person, firm orcorporation, approved by the building official, who is compe-tent and experienced in the application of engineering princi-ples to materials, methods or systems analyses.

ARCHITECTURAL TERRA COTTA. Plain or ornamen-tal hard-burned modified clay units, larger in size than brick,with glazed or unglazed ceramic finish.

AREA (for masonry).

Gross cross-sectional. The area delineated by the out-to-out specified dimensions of masonry in the plane underconsideration.

Net cross-sectional. The area of masonry units, grout andmortar crossed by the plane under consideration based onout-to-out specified dimensions.

AREA, BUILDING. The area included within surroundingexterior walls (or exterior walls and fire walls) exclusive ofvent shafts and courts. Areas of the building not providedwith surrounding walls shall be included in the building areaif such areas are included within the horizontal projection ofthe roof or floor above.

AREA OF REFUGE. An area where persons unable to usestairways can remain temporarily to await instructions orassistance during emergency evacuation.

AREAWAY. A subsurface space adjacent to a building openat the top or protected at the top by a grating or guard.

ASSEMBLY SEATING, MULTILEVEL. See “Multilevelassembly seating.”

ATRIUM. An opening connecting two or more stories otherthan enclosed stairways, elevators, hoistways, escalators,plumbing, electrical, air-conditioning or other equipment,which is closed at the top and not defined as a mall. Stories,as used in this definition, do not include balconies within

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DEFINITIONS


assembly groups or mezzanines that comply with Section505.

ATTIC. The space between the ceiling beams of the top storyand the roof rafters.

[F] AUDIBLE ALARM NOTIFICATION APPLIANCE.A notification appliance that alerts by the sense of hearing.

AUTOCLAVED AERATED CONCRETE (AAC). Lowdensity cementitious product of calcium silicate hydrates,whose material specifications are defined in ASTM C 1386.

[F] AUTOMATIC. As applied to fire protection devices, adevice or system providing an emergency function withoutthe necessity for human intervention and activated as a resultof a predetermined temperature rise, rate of temperature riseor combustion products.

[F] AUTOMATIC FIRE-EXTINGUISHING SYSTEM.An approved system of devices and equipment which auto-matically detects a fire and discharges an approved fire-extin-guishing agent onto or in the area of a fire.

[F] AUTOMATIC SMOKE DETECTION SYSTEM. Afire alarm system that has initiation devices that utilize smokedetectors for protection of an area such as a room or spacewith detectors to provide early warning of fire.

[F] AUTOMATIC SPRINKLER SYSTEM. An automaticsprinkler system, for fire protection purposes, is an integratedsystem of underground and overhead piping designed inaccordance with fire protection engineering standards. Thesystem includes a suitable water supply. The portion of thesystem above the ground is a network of specially sized orhydraulically designed piping installed in a structure or area,generally overhead, and to which automatic sprinklers areconnected in a systematic pattern. The system is usually acti-vated by heat from a fire and discharges water over the firearea.

[F] AVERAGE AMBIENT SOUND LEVEL. The rootmean square, A-weighted sound pressure level measured overa 24-hour period, or the time any person is present, whichevertime period is less.

AWNING. A protective covering with a nonrigid surfaceprojecting from a building. ((An architectural projection thatprovides weather protection, identity or decoration and is par-tially or wholly supported by the building to which it isattached. An awning is comprised of a lightweight framestructure over which a covering is attached. ))

AWNING SIGN. A sign applied to the surface of an awningor canopy.

BACKING. The wall or surface to which the veneer issecured.

[F] BALED COTTON. A natural seed fiber wrapped in andsecured with industry accepted materials, usually consistingof burlap, woven polypropylene, polyethylene or cotton orsheet polyethylene, and secured with steel, synthetic or wirebands or wire; also includes linters (lint removed from thecottonseed) and motes (residual materials from the ginningprocess).

[F] BALED COTTON, DENSELY PACKED. Cottonmade into banded bales with a packing density of at least 22

pounds per cubic foot (360 kg/m3), and dimensions comply-ing with the following: a length of 55 inches (1397 mm), awidth of 21 inches (533.4 mm) and a height of 27.6 to 35.4inches (701 to 899 mm).

BALLAST. In roofing, ballast comes in the form of largestones or paver systems or light-weight interlocking paversystems and is used to provide uplift resistance for roofingsystems that are not adhered or mechanically attached to theroof deck.

[F] BARRICADE. A structure that consists of a combinationof walls, floor and roof, which is designed to withstand therapid release of energy in an explosion and which is fullyconfined, partially vented or fully vented; or other effectivemethod of shielding from explosive materials by a natural orartificial barrier.

Artificial barricade. An artificial mound or revetment aminimum thickness of 3 feet (914 mm).

Natural barricade. Natural features of the ground, suchas hills, or timber of sufficient density that the surroundingexposures that require protection cannot be seen from themagazine or building containing explosives when the treesare bare of leaves.

BASE FLOOD. The flood having a 1-percent chance ofbeing equaled or exceeded in any given year.

BASE FLOOD ELEVATION. The elevation of the baseflood, including wave height, relative to the National Geo-detic Vertical Datum (NGVD), North American VerticalDatum (NAVD) or other datum specified on the Flood Insur-ance Rate Map (FIRM).

BASEMENT (for flood loads). The portion of a buildinghaving its floor subgrade (below ground level) on all sides. This definition of “Basement” is limited in application to theprovisions of Section 1612.

BASEMENT. A story that is not a story above grade plane(see “Story above grade plane”). This definition of “Base-ment” does not apply to the provisions of Section 1612 forflood loads.

BEARING WALL STRUCTURE. A building or otherstructure in which vertical loads from floors and roofs are pri-marily supported by walls.

BED JOINT. The horizontal layer of mortar on which amasonry unit is laid.

BLEACHERS. Tiered seating supported on a dedicatedstructural system and two or more rows high and is not abuilding element (see “Grandstands”).

BOARDING HOUSE. A building arranged or used for lodg-ing for compensation, with or without meals, and not occu-pied as a single-family unit.

[F] BOILING POINT. The temperature at which the vaporpressure of a liquid equals the atmospheric pressure of 14.7pounds per square inch (psia) (101 kPa) or 760 mm of mer-cury. Where an accurate boiling point is unavailable for thematerial in question, or for mixtures which do not have a con-stant boiling point, for the purposes of this classification, the20-percent evaporated point of a distillation performed in


DEFINITIONS


accordance with ASTM D 86 shall be used as the boilingpoint of the liquid.

BOND BEAM. A horizontal grouted element withinmasonry in which reinforcement is embedded.

BRACED WALL LINE. A series of braced wall panels in asingle story that meets the requirements of Section 2308.3 or2308.12.4.

BRACED WALL PANEL. A section of wall braced inaccordance with Section 2308.9.3 or 2308.12.4.

BRICK.

Calcium silicate (sand lime brick). A pressed and subse-quently autoclaved unit that consists of sand and lime,with or without the inclusion of other materials.

Clay or shale. A solid or hollow masonry unit of clay orshale, usually formed into a rectangular prism, then burnedor fired in a kiln; brick is a ceramic product.

Concrete. A concrete masonry unit made from Portlandcement, water, and suitable aggregates, with or without theinclusion of other materials.

[A] BUILDING. Any structure used or intended for support-ing or sheltering any use or occupancy.

BUILDING AREA. See “Area, building.”

BUILDING ELEMENT. A fundamental component ofbuilding construction, listed in Table 601, which may or maynot be of fire-resistance-rated construction and is constructedof materials based on the building type of construction.

BUILDING HEIGHT. See “Height, building.”

BUILDING LINE. The line established by law, beyondwhich a building shall not extend, except as specifically pro-vided by law.

[A] BUILDING OFFICIAL. The ((officer or other desig-nated authority charged with the administration and enforce-ment of this code)) Director of the Department of Planningand Development, or a duly authorized representative.

BUILT-UP ROOF COVERING. Two or more layers of feltcemented together and surfaced with a cap sheet, mineralaggregate, smooth coating or similar surfacing material.

CABLE-RESTRAINED, AIR-SUPPORTED STRUC-TURE. A structure in which the uplift is resisted by cables orwebbings which are anchored to either foundations or deadmen. Reinforcing cable or webbing is attached by variousmethods to the membrane or is an integral part of the mem-brane. This is not a cable-supported structure.

CANOPY. ((A permanent structure or architectural projec-tion of rigid construction over which a covering is attachedthat provides weather protection, identity or decoration. Acanopy is permitted to be structurally independent or sup-ported by attachment to a building on one or more sides.)) Aprotective covering with a rigid surface projecting from abuilding. Marquees are a type of canopy.

[F] CARBON DIOXIDE EXTINGUISHING SYSTEMS.A system supplying carbon dioxide (CO2) from a pressurizedvessel through fixed pipes and nozzles. The system includes amanual- or automatic-actuating mechanism.

CARE SUITE. A group of treatment rooms, care recipientsleeping rooms and their associated support rooms or spacesand circulation space within Group I-2 occupancies wherestaff are in attendance for supervision of all care recipientswithin the suite, and the suite is in compliance with therequirements of Section 407.4.3.

CAST STONE. A building stone manufactured from Port-land cement concrete precast and used as a trim, veneer orfacing on or in buildings or structures.

[F] CEILING LIMIT. The maximum concentration of anair-borne contaminant to which one may be exposed. Theceiling limits utilized are those published in DOL 29 CFRPart 1910.1000. The ceiling Recommended Exposure Limit(REL-C) concentrations published by the U.S. National Insti-tute for Occupational Safety and Health (NIOSH), ThresholdLimit Value—Ceiling (TLV-C) concentrations published bythe American Conference of Governmental Industrial Hygen-ists (ACGIH), Ceiling Work place Environmental ExposureLevel (WEEL-Ceiling) Guides published by the AmericanIndustrial Hygiene Association (AIHA), and other approved,consistent measures are allowed as surrogates for hazardoussubstances not listed in DOL 29 CFR Part 1910.1000.

CEILING RADIATION DAMPER. A listed deviceinstalled in a ceiling membrane of a fire-resistance-ratedfloor/ceiling or roof/ceiling assembly to limit automaticallythe radiative heat transfer through an air inlet/outlet opening.

CELL (Group I-3 occupancy). A room within a housingunit in a detention or correctional facility used to confineinmates or prisoners.

CELL (masonry). A void space having a gross cross-sec-tional area greater than 11/2 square inches (967 mm2).

CELL TIER. Levels of cells vertically stacked above oneanother within a housing unit.

CEMENT PLASTER. A mixture of portland or blendedcement, Portland cement or blended cement and hydratedlime, masonry cement or plastic cement and aggregate andother approved materials as specified in this code.

CERAMIC FIBER BLANKET. A mineral wool insulationmaterial made of alumina-silica fibers and weighing 4 to 10pounds per cubic foot (pcf) (64 to 160 kg/m3).

CERTIFICATE OF COMPLIANCE. A certificate statingthat materials and products meet specified standards or thatwork was done in compliance with approved constructiondocuments.

[W] CHILD CARE. The care of children during any periodof a 24-hour day.

[W] CHILD CARE, FAMILY HOME. A child care facil-ity, licensed by the state of Washington, located in the dwell-ing of the person or persons under whose direct care andsupervision the child is placed, for the care of 12 or fewerchildren, including children who reside at the home.

[M] CHIMNEY. A primarily vertical enclosure containingone or more passageways for conveying flue gases to the out-side atmosphere.

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DEFINITIONS


CHIMNEY TYPES.

High-heat appliance type. An approved chimney forremoving the products of combustion from fuel-burning,high-heat appliances producing combustion gases inexcess of 2000°F (1093°C) measured at the appliance flueoutlet (see Section 2113.11.3).

Low-heat appliance type. An approved chimney forremoving the products of combustion from fuel-burning,low-heat appliances producing combustion gases not inexcess of 1000°F (538°C) under normal operating condi-tions, but capable of producing combustion gases of1400°F (760°C) during intermittent forces firing for peri-ods up to 1 hour. Temperatures shall be measured at theappliance flue outlet.

Masonry type. A field-constructed chimney of solidmasonry units or stones.

Medium-heat appliance type. An approved chimney forremoving the products of combustion from fuel-burning,medium-heat appliances producing combustion gases notexceeding 2000°F (1093°C) measured at the applianceflue outlet (see Section 2113.11.2).

CIRCULATION PATH. An exterior or interior way of pas-sage from one place to another for pedestrians.

[F] CLEAN AGENT. Electrically nonconducting, volatile orgaseous fire extinguishant that does not leave a residue uponvaporation.

CLEANOUT. An opening to the bottom of a grout space ofsufficient size and spacing to allow the removal of debris.

CLINIC, OUTPATIENT. Buildings or portions thereofused to provide medical care on less than a 24-hour basis topersons who are not rendered incapable of self-preservationby the services provided.

CLOSED CIRCUIT TELEPHONE. A telephone with adedicated line such as a house phone, courtesy phone orphone that must be used to gain entrance to a facility.

[F] CLOSED SYSTEM. The use of a solid or liquid hazard-ous material involving a closed vessel or system that remainsclosed during normal operations where vapors emitted by theproduct are not liberated outside of the vessel or system andthe product is not exposed to the atmosphere during normaloperations; and all uses of compressed gases. Examples ofclosed systems for solids and liquids include product con-veyed through a piping system into a closed vessel, system orpiece of equipment.

COLLAR JOINT. Vertical longitudinal space betweenwythes of masonry or between masonry wythe and backupconstruction that is permitted to be filled with mortar orgrout.

COLLECTOR. A horizontal diaphragm element paralleland in line with the applied force that collects and transfersdiaphragm shear forces to the vertical elements of the lateral-force-resisting system and/or distributes forces within thediaphragm.

COMBINATION FIRE/SMOKE DAMPER. A listeddevice installed in ducts and air transfer openings designed toclose automatically upon the detection of heat and resist the

passage of flame and smoke. The device is installed to oper-ate automatically, controlled by a smoke detection system,and where required, is capable of being positioned from a firecommand center

[F] COMBUSTIBLE DUST. Finely divided solid materialthat is 420 microns or less in diameter and which, when dis-persed in air in the proper proportions, could be ignited by aflame, spark or other source of ignition. Combustible dustwill pass through a U.S. No. 40 standard sieve.

[F] COMBUSTIBLE FIBERS. Readily ignitable and free-burning materials in a fibrous or shredded form, such ascocoa fiber, cloth, cotton, excelsior, hay, hemp, henequen,istle, jute, kapok, oakum, rags, sisal, Spanish moss, straw,tow, wastepaper, certain synthetic fibers or other like materi-als. This definition does not include densely packed baledcotton.

[F] COMBUSTIBLE LIQUID. A liquid having a closedcup flash point at or above 100°F (38°C). Combustible liq-uids shall be subdivided as follows:

Class II. Liquids having a closed cup flash point at orabove 100°F (38°C) and below 140°F (60°C).

Class IIIA. Liquids having a closed cup flash point at orabove 140°F (60°C) and below 200°F (93°C).

Class IIIB. Liquids having a closed cup flash point at orabove 200°F (93°C).

The category of combustible liquids does not include com-pressed gases or cryogenic fluids.

COMMON PATH OF EGRESS TRAVEL. That portion ofexit access which the occupants are required to traversebefore two separate and distinct paths of egress travel to twoexits are available. Paths that merge are common paths oftravel. Common paths of egress travel shall be includedwithin the permitted travel distance.

COMMON USE. Interior or exterior circulation paths,rooms, spaces or elements that are not for public use and aremade available for the shared use of two or more people.

[F] COMPRESSED GAS. A material, or mixture of materi-als, that:

1. Is a gas at 68°F (20°C) or less at 14.7 pounds per squareinch atmosphere (psia) (101 kPa) of pressure; and

2. Has a boiling point of 68°F (20°C) or less at 14.7 psia(101 kPa) which is either liquefied, nonliquefied or insolution, except those gases which have no otherhealth- or physical-hazard properties are not consideredto be compressed until the pressure in the packagingexceeds 41 psia (282 kPa) at 68°F (20°C).

The states of a compressed gas are categorized as follows:

1. Nonliquefied compressed gases are gases, other thanthose in solution, which are in a packaging under thecharged pressure and are entirely gaseous at a tem-perature of 68°F (20°C).

2. Liquefied compressed gases are gases that, in apackaging under the charged pressure, are partiallyliquid at a temperature of 68°F (20°C).


DEFINITIONS


3. Compressed gases in solution are nonliquefied gasesthat are dissolved in a solvent.

4. Compressed gas mixtures consist of a mixture oftwo or more compressed gases contained in a pack-aging, the hazard properties of which are repre-sented by the properties of the mixture as a whole.

COMPRESSIVE STRENGTH OF MASONRY. Maxi-mum compressive force resisted per unit of net cross-sec-tional area of masonry, determined by the testing of masonryprisms

CONCRETE

Carbonate aggregate. Concrete made with aggregatesconsisting mainly of calcium or magnesium carbonate,such as limestone or dolomite, and containing 40 percentor less quartz, chert or flint.

Cellular. A lightweight insulating concrete made by mix-ing a preformed foam with Portland cement slurry andhaving a dry unit weight of approximately 30 pcf (480 kg/m3).

Lightweight aggregate. Concrete made with aggregatesof expanded clay, shale, slag or slate or sintered fly ash orany natural lightweight aggregate meeting ASTM C 330and possessing equivalent fire-resistance properties andweighing 85 to 115 pcf (1360 to 1840 kg/m3).

Perlite. A lightweight insulating concrete having a dryunit weight of approximately 30 pcf (480 kg/m3) madewith perlite concrete aggregate. Perlite aggregate is pro-duced from a volcanic rock which, when heated, expandsto form a glass-like material of cellular structure.

Sand-lightweight. Concrete made with a combination ofexpanded clay, shale, slag, slate, sintered fly ash, or anynatural lightweight aggregate meeting ASTM C 330 andpossessing equivalent fire-resistance properties and natu-ral sand. Its unit weight is generally between 105 and 120pcf (1680 and 1920 kg/m3).

Siliceous aggregate. Concrete made with normal-weightaggregates consisting mainly of silica or compounds otherthan calcium or magnesium carbonate, which containsmore than 40-percent quartz, chert or flint.

Vermiculite. A light weight insulating concrete madewith vermiculite concrete aggregate which is laminatedmicaceous material produced by expanding the ore at hightemperatures. When added to a Portland cement slurry theresulting concrete has a dry unit weight of approximately30 pcf (480 kg/m3).

CONGREGATE LIVING FACILITIES. A building orpart thereof that contains sleeping units where residents sharebathroom and/or kitchen facilities.

[F] CONSTANTLY ATTENDED LOCATION. A desig-nated location at a facility staffed by trained personnel on acontinuous basis where alarm or supervisory signals are mon-itored and facilities are provided for notification of the firedepartment or other emergency services.

[A] CONSTRUCTION DOCUMENTS. Written, graphicand pictorial documents, in electronic or paper format, pre-pared or assembled for describing the design, location and

physical characteristics of the elements of a project necessaryfor obtaining a building permit and final approval of con-struction.

CONSTRUCTION TYPES. See Section 602.

Type I. See Section 602.2.

Type II. See Section 602.2.

Type III. See Section 602.3.

Type IV. See Section 602.4.

Type V. See Section 602.5.

[F] CONTINUOUS GAS DETECTION SYSTEM. A gasdetection system where the analytical instrument is main-tained in continuous operation and sampling is performedwithout interruption. Analysis is allowed to be performed ona cyclical basis at intervals not to exceed 30 minutes.

[F] CONTROL AREA. Spaces within a building wherequantities of hazardous materials not exceeding the maxi-mum allowable quantities per control area are stored, dis-pensed, used or handled. See also the definition of “Outdoorcontrol area” in the International Fire Code.

CONTROLLED LOW-STRENGTH MATERIAL. A self-compacted, cementitious material used primarily as a backfillin place of compacted fill.

CONVENTIONAL LIGHT-FRAME CONSTRUCTION. A type of construction whose primary structural elements areformed by a system of repetitive wood-framing members. SeeSection 2308 for conventional light-frame construction provi-sions.

CORNICE. A projecting horizontal molded element locatedat or near the top of an architectural feature.

CORRIDOR. An enclosed exit access component thatdefines and provides a path of egress travel.

CORROSION RESISTANCE. The ability of a material towithstand deterioration of its surface or its properties whenexposed to its environment.

[F] CORROSIVE. A chemical that causes visible destruc-tion of, or irreversible alterations in, living tissue by chemicalaction at the point of contact. A chemical shall be consideredcorrosive if, when tested on the intact skin of albino rabbitsby the method described in DOTn 49 CFR, Part 173.137,such chemical destroys or changes irreversibly the structureof the tissue at the point of contact following an exposureperiod of 4 hours. This term does not refer to action on inani-mate surfaces.

COURT. An open, uncovered space, unobstructed to the sky,bounded on three or more sides by exterior building walls orother enclosing devices.

COVERED BOAT MOORAGE. A pier or system of float-ing or fixed accessways to which vessels on water may besecured, and any portion of which is covered by a roof.

COVERED MALL BUILDING. A single building enclos-ing a number of tenants and occupants, such as retail stores,drinking and dining establishments, entertainment andamusement facilities, passenger transportation terminals,offices and other similar uses wherein two or more tenants

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have a main entrance into one or more malls. Anchor build-ings shall not be considered as a part of the covered mallbuilding. The term “covered mall building” shall includeopen mall buildings as defined below.

Mall. A roofed or covered common pedestrian area withina covered mall building that serves as access for two ormore tenants and not to exceed three levels that are opento each other. The term “mall” shall include open malls asdefined below.

Open mall. An unroofed common pedestrian way servinga number of tenants not exceeding three levels. Circulationat levels above grade shall be permitted to include openexterior balconies leading to exits discharging at grade.

Open mall building. Several structures housing a numberof tenants, such as retail stores, drinking and dining estab-lishments, entertainment and amusement facilities, offices,and other similar uses, wherein two or more tenants have amain entrance into one or more open malls. Anchor build-ings are not considered as a part of the open mall building.

CRIPPLE WALL. A framed stud wall extending from thetop of the foundation to the underside of floor framing for thelowest occupied floor level.

CROSS-LAMINATED TIMBER. A prefabricated engi-neered wood product consisting of at least three layers ofsolid-sawn lumber or structural composite lumber where theadjacent layers are cross-oriented and bonded with structuraladhesive to form a solid wood element.

[F] CRYOGENIC FLUID. A liquid having a boiling pointlower than -150°F (-101°C) at 14.7 pounds per square inchatmosphere (psia) (an absolute pressure of 101 kPa).

CUSTODIAL CARE. Assistance with day-to-day livingtasks; such as assistance with cooking, taking medication,bathing, using toilet facilities and other tasks of daily living.Custodial care includes persons receiving care who evacuateat a slower rate and/or who have mental and psychiatric com-plications.

DALLE GLASS. A decorative composite glazing materialmade of individual pieces of glass that are embedded in a castmatrix of concrete or epoxy.

DAMPER. See “Ceiling radiation damper,” “Combinationfire/smoke damper,” “Fire damper” and “Smoke damper.”

((DANGEROUS. Any building, structure or portion thereofthat meets any of the conditions described below shall bedeemed dangerous:

1. The building or structure has collapsed, has partiallycollapsed, has moved off its foundation or lacks thenecessary support of the ground.

2. There exists a significant risk of collapse, detachmentor dislodgment of any portion, member, appurtenanceor ornamentation of the building or structure under ser-vice loads.))

[F] DAY BOX. A portable magazine designed to hold explo-sive materials constructed in accordance with the require-ments for a Type 3 magazine as defined and classified inChapter 56 of the International Fire Code.

DEAD LOAD. The weight of materials of constructionincorporated into the building, including but not limited towalls, floors, roofs, ceilings, stairways, built-in partitions,finishes, cladding and other similarly incorporated architec-tural and structural items, and the weight of fixed serviceequipment, such as cranes, plumbing stacks and risers, elec-trical feeders, heating, ventilating and air-conditioning sys-tems and automatic sprinkler systems.

DECORATIVE GLASS. A carved, leaded or Dalle glass orglazing material whose purpose is decorative or artistic, notfunctional; whose coloring, texture or other design qualitiesor components cannot be removed without destroying theglazing material and whose surface, or assembly into which itis incorporated, is divided into segments.

[F] DECORATIVE MATERIALS. All materials appliedover the building interior finish for decorative, acoustical orother effect (such as curtains, draperies, fabrics, streamersand surface coverings), and all other materials utilized fordecorative effect (such as batting, cloth, cotton, hay, stalks,straw, vines, leaves, trees, moss and similar items), includingfoam plastics and materials containing foam plastics. Decora-tive materials do not include floor coverings, ordinary win-dow shades, interior finish and materials 0.025 inch (0.64mm) or less in thickness applied directly to and adheringtightly to a substrate.

DEEP FOUNDATION. A deep foundation is a foundationelement that does not satisfy the definition of a shallow foun-dation.

DEFERRED SUBMITTALS. Those portions of the designthat are not submitted at the time of the application and thatare to be submitted to the building official within a specifiedperiod. Deferred submittals include but are not limited toshop drawings for truss systems and sprinkler systems.

[F] DEFLAGRATION. An exothermic reaction, such as theextremely rapid oxidation of a flammable dust or vapor in air,in which the reaction progresses through the unburned mate-rial at a rate less than the velocity of sound. A deflagrationcan have an explosive effect.

[F] DELUGE SYSTEM. A sprinkler system employingopen sprinklers attached to a piping system connected to awater supply through a valve that is opened by the operationof a detection system installed in the same areas as the sprin-klers. When this valve opens, water flows into the piping sys-tem and discharges from all sprinklers attached thereto.

DESIGN DISPLACEMENT. See Section 1905.1.1.

DESIGN EARTHQUAKE GROUND MOTION. Theearthquake ground motion that buildings and structures arespecifically proportioned to resist in Section 1613.

DESIGN FLOOD. The flood associated with the greater ofthe following two areas:

1. Area with a flood plain subject to a 1-percent or greaterchance of flooding in any year; or

2. Area designated as a flood hazard area on a commu-nity’s flood hazard map, or otherwise legally desig-nated.


DEFINITIONS


DESIGN FLOOD ELEVATION. The elevation of the“design flood,” including wave height, relative to the datumspecified on the community’s legally designated flood hazardmap. In areas designated as Zone AO, the design flood eleva-tion shall be the elevation of the highest existing grade of thebuilding’s perimeter plus the depth number (in feet) specifiedon the flood hazard map. In areas designated as Zone AOwhere a depth number is not specified on the map, the depthnumber shall be taken as being equal to 2 feet (610 mm).

DESIGN PROFESSIONAL, REGISTERED. See “Regis-tered design professional.”

DESIGN PROFESSIONAL IN RESPONSIBLE CHARGE,REGISTERED. See “Registered design professional inresponsible charge.”

DESIGN STRENGTH. The product of the nominal strengthand a resistance factor (or strength reduction factor).

DESIGNATED SEISMIC SYSTEM. Those nonstructuralcomponents that require design in accordance with Chapter13 of ASCE 7 and for which the component importance fac-tor, Ip, is greater than 1 in accordance with Section 13.1.3 ofASCE 7.

[F] DETACHED BUILDING. A separate single-storybuilding, without a basement or crawl space, used for thestorage or use of hazardous materials and located anapproved distance from all structures.

DETAILED PLAIN CONCRETE STRUCTURAL WALL.See Section 1905.1.1

DETECTABLE WARNING. A standardized surface fea-ture built in or applied to walking surfaces or other elementsto warn visually impaired persons of hazards on a circulationpath.

[F] DETECTOR, HEAT. A fire detector that senses heat—either abnormally high temperature or rate of rise, or both.

[F] DETONATION. An exothermic reaction characterizedby the presence of a shock wave in the material which estab-lishes and maintains the reaction. The reaction zone pro-gresses through the material at a rate greater than the velocityof sound. The principal heating mechanism is one of shockcompression. Detonations have an explosive effect.

DETOXIFICATION FACILITIES. Facilities that providetreatment for substance abuse, serving care recipients who areincapable of self-preservation or who are harmful to them-selves or others.

DIAPHRAGM. A horizontal or sloped system acting totransmit lateral forces to the vertical-resisting elements.When the term “diaphragm” is used, it shall include horizon-tal bracing systems.

Diaphragm, blocked. In light-frame construction, a dia-phragm in which all sheathing edges not occurring on aframing member are supported on and fastened to block-ing.

Diaphragm boundary. In light-frame construction, alocation where shear is transferred into or out of the dia-phragm sheathing. Transfer is either to a boundary ele-ment or to another force-resisting element.

Diaphragm chord. A diaphragm boundary element per-pendicular to the applied load that is assumed to take axialstresses due to the diaphragm moment.

Diaphragm flexible. A diaphragm is flexible for the pur-pose of distribution of story shear and torsional momentwhere so indicated in Section 12.3.1 of ASCE 7.

Diaphragm, rigid. A diaphragm is rigid for the purposeof distribution of story shear and torsional moment whenthe lateral deformation of the diaphragm is less than orequal to two times the average story drift.

Diaphram, unblocked. A diaphragm that has edge nailingat supporting members only. Blocking between supportingstructural members at panel edges is not included. Dia-phragm panels are field nailed to supporting members.

DIMENSIONS.

Nominal. The specified dimension plus an allowance forthe joints with which the units are to be laid. Nominaldimensions are usually stated in whole numbers. Thick-ness is given first, followed by height and then length.

Specified. Dimensions specified for the manufacture orconstruction of a unit, joint element.

[F] DISPENSING. The pouring or transferring of any mate-rial from a container, tank or similar vessel, whereby vapors,dusts, fumes, mists or gases are liberated to the atmosphere.

DISPLAY SURFACE. The area of a sign structure used todisplay the advertising message.

DOOR, BALANCED. A door equipped with double-pivotedhardware so designed as to cause a semicounter balancedswing action when opening.

DORMITORY. A space in a building where group sleepingaccommodations are provided in one room, or in a series ofclosely associated rooms, for persons not members of thesame family group, under joint occupancy and single man-agement, as in college dormitories or fraternity houses.

DRAFTSTOP. A material, device or construction installedto restrict the movement of air within open spaces of con-cealed areas of building components such as crawl spaces,floor/ceiling assemblies, roof/ceiling assemblies and attics.

DRAG STRUT. See “Collector.”

DRILLED SHAFT. A drilled shaft is a cast-in-place deepfoundation element constructed by drilling a hole (with orwithout permanent casing) into soil or rock and filling it withfluid concrete.

Socketed drilled shaft. A socketed drilled shaft is adrilled shaft with a permanent pipe or tube casing thatextends down to bedrock and an uncased socket drilledinto the bedrock.

[F] DRY-CHEMICAL EXTINGUISHING AGENT. Apowder composed of small particles, usually of sodium bicar-bonate, potassium bicarbonate, urea-potassium-based bicar-bonate, potassium chloride or monoammonium phosphate,with added particulate material supplemented by specialtreatment to provide resistance to packing, resistance to mois-ture absorption (caking) and the proper flow capabilities.

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DEFINITIONS


DRY FLOODPROOFING. A combination of design modi-fications that results in a building or structure, including theattendant utility and sanitary facilities, being water tight withwalls substantially impermeable to the passage of water andwith structural components having the capacity to resist loadsas identified in ASCE 7.

DURATION OF LOAD. The period of continuous applica-tion of a given load, or the aggregate of periods of intermit-tent applications of the same load.

DWELLING. A building that contains one or two dwellingunits used, intended or designed to be used, rented, leased, letor hired out to be occupied for living purposes.

DWELLING UNIT. A single unit providing complete, inde-pendent living facilities for one or more persons, includingpermanent provisions for living, sleeping, eating, cookingand sanitation.

DWELLING UNIT OR SLEEPING UNIT, MULTI-STORY. See definition for “Multistory unit.”

EGRESS COURT. A court or yard which provides access toa public way for one or more exits.

ELECTRIC SIGN. Any sign containing electrical wiring,but not including signs illuminated by an exterior lightsource.

[F] ELEVATOR GROUP. A grouping of elevators in abuilding located adjacent or directly across from one anotherthat responds to common hall call buttons.

[F] EMERGENCY ALARM SYSTEM. A system to pro-vide indication and warning of emergency situations involv-ing hazardous materials.

[F] EMERGENCY CONTROL STATION. An approvedlocation on the premises where signals from emergencyequipment are received and which is staffed by trained per-sonnel.

EMERGENCY ESCAPE AND RESCUE OPENING. Anoperable window, door or other similar device that providesfor a means of escape and access for rescue in the event of anemergency.

EMERGENCY POWER SYSTEM. An electrical systemthat complies with Seattle Electrical Code Article 700.

[F] EMERGENCY VOICE/ALARM COMMUNICA-TIONS. Dedicated manual or automatic facilities for origi-nating and distributing voice instructions, as well as alert andevacuation signals pertaining to a fire emergency, to theoccupants of a building.

EMPLOYEE WORK AREA. All or any portion of a spaceused only by employees and only for work. Corridors, toiletrooms, kitchenettes and break rooms are not employee workareas.

ENTRANCE, PUBLIC. See “Public entrance.”

ENTRANCE, RESTRICTED. See “Restricted entrance.”

ENTRANCE, SERVICE. See “Service entrance.”

EQUIPMENT PLATFORM. An unoccupied, elevated plat-form used exclusively for mechanical systems or industrialprocess equipment, including the associated elevated walk-

ways, stairs, alternating tread devices and ladders necessaryto access the platform (see Section 505.3).

ESSENTIAL FACILITIES. Buildings and other structuresthat are intended to remain operational in the event ofextreme environmental loading from flood, wind, snow orearthquakes

[F] EXHAUSTED ENCLOSURE. An appliance or piece ofequipment that consists of a top, a back and two sides provid-ing a means of local exhaust for capturing gases, fumes,vapors and mists. Such enclosures include laboratory hoods,exhaust fume hoods and similar appliances and equipmentused to locally retain and exhaust the gases, fumes, vaporsand mists that could be released. Rooms or areas providedwith general ventilation, in themselves, are not exhaustedenclosures.

EXISTING BUILDING, EXISTING STRUCTURE(Except for Section 1612.2 ((For Chapter 34))). A buildingor structure erected prior to the date of adoption of the appro-priate code, or one for which a valid Certificate of Occupancy((legal building permit)) has been issued.

EXISTING CONSTRUCTION. Any buildings and struc-tures for which the start of construction commenced beforethe effective date of the community’s first flood plain man-agement code, ordinance or standard. “Existing construction”is also referred to as “existing structures.”

EXISTING STRUCTURE (For Section 1612.2). See“Existing construction”.

EXIT. That portion of a means of egress system between theexit access and the exit discharge or public way. Exit compo-nents include exterior exit doors at the level of exit discharge,interior exit stairways, interior exit ramps, exit passageways,exterior exit stairways and exterior exit ramps and horizontalexits.

EXIT ACCESS. That portion of a means of egress systemthat leads from any occupied portion of a building or struc-ture to an exit.

EXIT ACCESS DOORWAY. A door or access point alongthe path of egress travel from an occupied room, area or spacewhere the path of egress enters an intervening room, corri-dor, exit access stair or exit access ramp.

EXIT ACCESS RAMP. An interior ramp that is not arequired interior exit ramp.

EXIT ACCESS STAIRWAY. An interior stairway that isnot a required interior exit stairway.

EXIT DISCHARGE. That portion of a means of egress sys-tem between the termination of an exit and a public way.

EXIT DISCHARGE, LEVEL OF. The story at the point atwhich an exit terminates and an exit discharge begins.

EXIT HARDWARE, FIRE. See “Fire exit hardware.”

EXIT, HORIZONTAL. A path of egress travel from onebuilding to an area in another building on approximately thesame level, or a path of egress travel through or around a wallor partition to an area on approximately the same level in thesame building, which affords safety from fire and smoke

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DEFINITIONS


from the area of incidence and areas communicating there-with.

EXIT PASSAGEWAY. An exit component that ((is sepa-rated from other interior spaces of a building or structure byfire-resistance-rated construction and opening protectives,and)) provides for a protected path of egress travel in a hori-zontal direction to an exit or to the exit discharge.

EXPANDED VINYL WALL COVERING. Wall coveringconsisting of a woven textile backing, an expanded vinyl basecoat layer and a nonexpanded vinyl skin coat. The expandedbase coat layer is a homogeneous vinyl layer that contains ablowing agent. During processing, the blowing agent decom-poses, causing this layer to expand by forming closed cells.The total thickness of the wall covering is approximately0.055 inch to 0.070 inch (1.4 mm to 1.78 mm).

[F] EXPLOSION. An effect produced by the sudden violentexpansion of gases, which may be accompanied by a shockwave or disruption, or both, of enclosing materials or struc-tures. An explosion could result from any of the following:

1. Chemical changes such as rapid oxidation, deflagrationor detonation, decomposition of molecules and run-away polymerization (usually detonations).

2. Physical changes such as pressure tank ruptures.

3. Atomic changes (nuclear fission or fusion).

[F] EXPLOSIVE. A chemical compound, mixture or device,the primary or common purpose of which is to function byexplosion. The term includes, but is not limited to, dynamite,black powder, pellet powder, initiating explosives, detona-tors, safety fuses, squibs, detonating cord, igniter cord, ignit-ers and display fireworks, 1.3G.

The term “explosive” includes any material determined tobe within the scope of USC Title 18: Chapter 40 and alsoincludes any material classified as an explosive other thanconsumer fireworks, 1.4G by the hazardous materials regula-tions of DOTn 49 CFR Parts 100-185.

High explosive. Explosive material, such as dynamite,which can be caused to detonate by means of a No. 8 testblasting cap when unconfined.

Low explosive. Explosive material that will burn or defla-grate when ignited. It is characterized by a rate of reactionthat is less than the speed of sound. Examples of lowexplosives include, but are not limited to, black powder;safety fuse; igniters; igniter cord; fuse lighters; fireworks,1.3G and propellants, 1.3C.

Mass-detonating explosives. Division 1.1, 1.2 and 1.5explosives alone or in combination, or loaded into varioustypes of ammunition or containers, most of which can beexpected to explode virtually instantaneously when asmall portion is subjected to fire, severe concussion,impact, the impulse of an initiating agent or the effect of aconsiderable discharge of energy from without. Materialsthat react in this manner represent a mass explosion haz-ard. Such an explosive will normally cause severe struc-tural damage to adjacent objects. Explosive propagationcould occur immediately to other items of ammunition andexplosives stored sufficiently close to and not adequately

protected from the initially exploding pile with a timeinterval short enough so that two or more quantities mustbe considered as one for quantity-distance purposes.

UN/DOTn Class 1 explosives. The former classificationsystem used by DOTn included the terms “high” and“low” explosives as defined herein. The following termsfurther define explosives under the current system appliedby DOTn for all explosive materials defined as hazardClass 1 materials. Compatibility group letters are used inconcert with the division to specify further limitations oneach division noted (i.e., the letter G identifies the materialas a pyrotechnic substance or article containing a pyro-technic substance and similar materials).

Division 1.1. Explosives that have a mass explosionhazard. A mass explosion is one which affects almostthe entire load instantaneously.

Division 1.2. Explosives that have a projection hazardbut not a mass explosion hazard.

Division 1.3. Explosives that have a fire hazard andeither a minor blast hazard or a minor projection hazardor both, but not a mass explosion hazard.

Division 1.4. Explosives that pose a minor explosionhazard. The explosive effects are largely confined tothe package and no projection of fragments of apprecia-ble size or range is to be expected. An external firemust not cause virtually instantaneous explosion ofalmost the entire contents of the package.

Division 1.5. Very insensitive explosives. This divisionis comprised of substances that have a mass explosionhazard, but that are so insensitive there is very littleprobability of initiation or of transition from burning todetonation under normal conditions of transport.

Division 1.6. Extremely insensitive articles which donot have a mass explosion hazard. This division is com-prised of articles that contain only extremely insensi-tive detonating substances and which demonstrate anegligible probability of accidental initiation or propa-gation.

EXTERIOR INSULATION AND FINISH SYSTEMS(EIFS). EIFS are nonstructural, nonload-bearing, exteriorwall cladding systems that consist of an insulation boardattached either adhesively or mechanically, or both, to thesubstrate; an integrally reinforced base coat and a texturedprotective finish coat.

EXTERIOR INSULATION AND FINISH SYSTEMS(EIFS) WITH DRAINAGE. An EIFS that incorporates ameans of drainage applied over a water-resistive barrier.

EXTERIOR SURFACES. Weather-exposed surfaces.

EXTERIOR WALL. A wall, bearing or nonbearing, that isused as an enclosing wall for a building, other than a firewall, and that has a slope of 60 degrees (1.05 rad) or greaterwith the horizontal plane.

EXTERIOR WALL COVERING. A material or assemblyof materials applied on the exterior side of exterior walls forthe purpose of providing a weather-resisting barrier, insula-tion or for aesthetics, including but not limited to, veneers,

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DEFINITIONS


siding, exterior insulation and finish systems, architecturaltrim and embellishments such as cornices, soffits, facias, gut-ters and leaders.

EXTERIOR WALL ENVELOPE. A system or assembly ofexterior wall components, including exterior wall finishmaterials, that provides protection of the building structuralmembers, including framing and sheathing materials, andconditioned interior space, from the detrimental effects of theexterior environment.

F RATING. The time period that the through-penetrationfirestop system limits the spread of fire through the penetra-tion when tested in accordance with ASTM E 814 or UL1479.

FABRIC PARTITION. A partition consisting of a finishedsurface made of fabric, without a continuous rigid backing,that is directly attached to a framing system in which the ver-tical framing members are spaced greater than 4 feet (1219mm) on center.

FABRICATED ITEM. Structural, load-bearing or lateralload-resisting assemblies consisting of materials assembledprior to installation in a building or structure, or subjected tooperations such as heat treatment, thermal cutting, cold work-ing or reforming after manufacture and prior to installation ina building or structure. Materials produced in accordancewith standard specifications referenced by this code, such asrolled structural steel shapes, steel reinforcing bars, masonryunits and wood structural panels, or in accordance with a ref-erenced standard which provides requirements for qualitycontrol done under the supervisions of a third-party qualitycontrol agency, shall not be considered “fabricated items.”

[F] FABRICATION AREA. An area within a semiconduc-tor fabrication facility and related research and developmentareas in which there are processes using hazardous produc-tion materials. Such areas are allowed to include ancillaryrooms or areas such as dressing rooms and offices that aredirectly related to the fabrication area processes.

FACILITY. All or any portion of buildings, structures, siteimprovements, elements and pedestrian or vehicular routeslocated on a site.

FACTORED LOAD. The product of a nominal load and aload factor.

FEE SUBTITLE. Seattle Municipal Code Title 22, SubtitleIX.

FIBER-CEMENT SIDING. A manufactured, fiber-rein-forcing product made with an inorganic hydraulic or calciumsilicate binder formed by chemical reaction and reinforcedwith discrete organic or inorganic nonasbestos fibers, or both.Additives that enhance manufacturing or product perfor-mance are permitted. Fiber-cement siding products haveeither smooth or textured faces and are intended for exteriorwall and related applications.

FIBER-REINFORCED POLYMER. A polymeric compos-ite material consisting of reinforcement fibers, such as glass,impregnated with a fiber-binding polymer which is thenmolded and hardened. Fiber-reinforced polymers are permit-

ted to contain cores laminated between fiber-reinforced poly-mer facings.

FIBERBOARD. A fibrous, homogeneous panel made fromlignocellulosic fibers (usually wood or cane) and having adensity of less than 31 pounds per cubic foot (pcf) (497 kg/m3) but more than 10 pcf (160 kg/m3).

FIELD NAILING. See “Nailing, field.”

[F] FIRE ALARM BOX, MANUAL. See “Manual firealarm box.”

[F] FIRE ALARM CONTROL UNIT. A system compo-nent that receives inputs from automatic and manual firealarm devices and may be capable of supplying power todetection devices and transponders or off-premises transmit-ters. The control unit may be capable of providing a transferof power to the notification appliances and transfer of condi-tion to relays or devices.

[F] FIRE ALARM SIGNAL. A signal initiated by a firealarm-initiating device such as a manual fire alarm box,automatic fire detector, waterflow switch or other devicewhose activation is indicative of the presence of a fire or firesignature.

[F] FIRE ALARM SYSTEM. A system or portion of a com-bination system consisting of components and circuitsarranged to monitor and annunciate the status of fire alarm orsupervisory signal-initiating devices and to initiate the appro-priate response to those signals.

FIRE AREA. The aggregate floor area enclosed andbounded by fire walls, fire barriers, exterior walls or hori-zontal assemblies of a building. Areas of the building not pro-vided with surrounding walls shall be included in the fire areaif such areas are included within the horizontal projection ofthe roof or floor next above.

FIRE BARRIER. A fire-resistance-rated wall assembly ofmaterials designed to restrict the spread of fire in which con-tinuity is maintained.

FIRE CODE OFFICIAL. The chief of the Seattle FireDepartment or a duly authorized representative.

[F] FIRE COMMAND CENTER. The principal attended orunattended location where the status of detection, alarm com-munications and control systems is displayed, and fromwhich the systems can be manually controlled.

FIRE DAMPER. A listed device installed in ducts and airtransfer openings designed to close automatically upon detec-tion of heat and resist the passage of flame. Fire dampers areclassified for use in either static systems that will automati-cally shut down in the event of a fire, or in dynamic systemsthat continue to operate during a fire. A dynamic fire damperis tested and rated for closure under elevated temperature air-flow.

FIRE DETECTION SYSTEM. A system of smoke or heatdetectors monitored at an approved central station, with norequirement for notification appliances in the building.

[F] FIRE DETECTOR, AUTOMATIC. A device designedto detect the presence of a fire signature and to initiate action.

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DEFINITIONS


FIRE DISTRICT. That part of the city within the boundarydescribed as follows:

Beginning at the intersection of the center line of AlaskanWay and Clay Street; thence northeasterly along the centerline of Clay Street to an intersection with the center line ofDenny Way; thence easterly along the center line of DennyWay to an intersection with the center line of Yale Avenue;thence southeasterly along the center line of Yale Avenue toan intersection with the center line of Interstate Highway 5;thence southerly and southeasterly along the centerline ofInterstate 5 to an intersection with the center line of 7th Ave-nue South; thence southerly along the center line of 7th Ave-nue South to an intersection with the center line of DearbornStreet; thence westerly along the center line of DearbornStreet to an intersection with the center line of Airport Way;thence northwesterly along the center line of Airport Way toan intersection with the center line of 4th Avenue South;thence southerly along the center line of 4th Avenue South toan intersection with the center line of South Royal BroughamWay; thence westerly along the center line of South RoyalBrougham Way to an intersection with the center line ofSouth Alaskan Way; thence southerly along the center line ofSouth Alaskan Way to an intersection with the center line ofSouth Massachusetts Street, thence westerly along the centerline of South Massachusetts Street to the Outer Harbor Linein Elliott Bay, thence northerly and northwesterly along theOuter Harbor Line to an intersection with the center line ofWest Harrison Street, thence easterly along the center line ofWest Harrison Street to an intersection with the center line ofAlaskan Way, then southeasterly along the center line ofAlaskan Way to the point of beginning.

Buildings and structures located partially within and par-tially outside the Fire District are considered to be located inthe Fire District. See Figure 202F.

FIRE DOOR. The door component of a fire door assembly.

FIRE DOOR ASSEMBLY. Any combination of a fire door,frame, hardware and other accessories that together provide aspecific degree of fire protection to the opening.

FIRE DOOR ASSEMBLY, FLOOR. See “Floor fire doorassembly.”

FIRE EXIT HARDWARE. Panic hardware that is listedfor use on fire door assemblies.

[F] FIRE LANE. A road or other passageway developed toallow the passage of fire apparatus. A fire lane is not neces-sarily intended for vehicular traffic other than fire apparatus.

FIRE PARTITION. A vertical assembly of materialsdesigned to restrict the spread of fire in which openings areprotected.

FIRE PROTECTION RATING. The period of time that anopening protective will maintain the ability to confine a fireas determined by tests prescribed in Section 716. Ratings arestated in hours or minutes.

[F] FIRE PROTECTION SYSTEM. Approved devices,equipment and systems or combinations of systems used todetect a fire, activate an alarm, extinguish or control a fire,control or manage smoke and products of a fire or any combi-nation thereof.

FIRE-RATED GLAZING. Glazing with either a fire pro-tection rating or a fire-resistance rating.

FIRE RESISTANCE. That property of materials or theirassemblies that prevents or retards the passage of excessiveheat, hot gases or flames under conditions of use.

FIRE-RESISTANCE RATING. The period of time a build-ing element, component or assembly maintains the ability toconfine a fire, continues to perform a given structural func-tion, or both, as determined by the tests, or the methods basedon tests, prescribed in Section 703.

FIRE-RESISTANT JOINT SYSTEM. An assemblage ofspecific materials or products that are designed, tested andfire-resistance rated in accordance with either ASTM E 1966or UL 2079 to resist for a prescribed period of time the pas-sage of fire through joints made in or between fire-resistance-rated assemblies.

FIRE-RETARDANT COVERING. Material with a flamespread rating of less than 15 when tested to ASTM E 84.

[F] FIRE SAFETY FUNCTIONS. Building and fire controlfunctions that are intended to increase the level of life safetyfor occupants or to control the spread of harmful effects offire.

FIRE SEPARATION DISTANCE. The distance measuredfrom the building face to one of the following:

1. The closest interior lot line;

2. To the ((centerline)) opposite side of a street, an alleyor public way; or

3. To an imaginary line between two buildings on the lot.

The distance shall be measured at right angles from theface of the wall.FIGURE 202F


DEFINITIONS


FIRE WALL. A fire-resistance-rated wall having protectedopenings, which restricts the spread of fire and extends con-tinuously from the foundation to or through the roof((, withsufficient structural stability under fire conditions to allowcollapse of construction on either side without collapse of thewall)).

FIRE WINDOW ASSEMBLY. A window constructed andglazed to give protection against the passage of fire.

FIREBLOCKING. Building materials, or materialsapproved for use as fireblocking, installed to resist the freepassage of flame to other areas of the building through con-cealed spaces.

FIREPLACE. A hearth and fire chamber or similar preparedplace in which a fire may be made and which is built in con-junction with a chimney.

FIREPLACE THROAT. The opening between the top ofthe firebox and the smoke chamber.

FIRESTOP, MEMBRANE PENETRATION. See “Mem-brane penetration firestop.”

FIRESTOP, PENETRATION. See “Penetration firestop.”

FIRESTOP SYSTEM, THROUGH PENETRATION. See “Through penetration firestop system.”

[F] FIREWORKS. Any composition or device for the pur-pose of producing a visible or audible effect for entertainmentpurposes by combustion, deflagration or detonation thatmeets the definition of 1.4G fireworks or 1.3G fireworks asset forth herein.

Fireworks, 1.3G. Large fireworks devices, which areexplosive materials, intended for use in fireworks displaysand designed to produce audible or visible effects by com-bustion, deflagration or detonation. Such 1.3G fireworksinclude, but are not limited to, firecrackers containingmore than 130 milligrams (2 grains) of explosive composi-tion, aerial shells containing more than 40 grams of pyro-technic composition, and other display pieces whichexceed the limits for classification as 1.4G fireworks. Such1.3G fireworks are also described as fireworks, UN0335by the DOTn.

Fireworks, 1.4G. Small fireworks devices containingrestricted amounts of pyrotechnic composition designedprimarily to produce visible or audible effects by combus-tion. Such 1.4G fireworks which comply with the con-struction, chemical composition and labeling regulationsof the DOTn for fireworks, UN0336, and the U.S. Con-sumer Product Safety Commission (CPSC) as set forth inCPSC 16 CFR: Parts 1500 and 1507, are not explosivematerials for the purpose of this code.

FIXED BASE OPERATOR (FBO). A commercial busi-ness granted the right by the airport sponsor to operate on anairport and provide aeronautical services, such as fueling,hangaring, tie-down and parking, aircraft rental, aircraftmaintenance and flight instruction.

FIXED SEATING. Furniture or fixture designed andinstalled for the use of sitting and secured in place includingbench-type seats and seats with or without backs or arm rests.

FLAME SPREAD. The propagation of flame over a surface.

FLAME SPREAD INDEX. A comparative measure,expressed as a dimensionless number, derived from visualmeasurements of the spread of flame versus time for a mate-rial tested in accordance with ASTM E 84 or UL 723.

[F] FLAMMABLE GAS. A material that is a gas at 68°F(20°C) or less at 14.7 pounds per square inch atmosphere(psia) (101 kPa) of pressure [a material that has a boilingpoint of 68°F (20°C) or less at 14.7 psia (101 kPa)] which:

1. Is ignitable at 14.7 psia (101 kPa) when in a mixture of13 percent or less by volume with air; or

2. Has a flammable range at 14.7 psia (101 kPa) with airof at least 12 percent, regardless of the lower limit.

The limits specified shall be determined at 14.7 psi (101kPa) of pressure and a temperature of 68°F (20°C) in accor-dance with ASTM E 681.

[F] FLAMMABLE LIQUEFIED GAS. A liquefied com-pressed gas which, under a charged pressure, is partially liq-uid at a temperature of 68°F (20°C) and which is flammable.

[F] FLAMMABLE LIQUID. A liquid having a closed cupflash point below 100°F (38°C). Flammable liquids are fur-ther categorized into a group known as Class I liquids. TheClass I category is subdivided as follows:

Class IA. Liquids having a flash point below 73°F (23°C)and a boiling point below 100°F (38°C).

Class IB. Liquids having a flash point below 73°F (23°C)and a boiling point at or above 100°F (38°C).

Class IC. Liquids having a flash point at or above 73°F(23°C) and below 100°F (38°C). The category of flamma-ble liquids does not include compressed gases or cryo-genic fluids.

[F] FLAMMABLE MATERIAL. A material capable ofbeing readily ignited from common sources of heat or at atemperature of 600°F (316°C) or less.

[F] FLAMMABLE SOLID. A solid, other than a blastingagent or explosive, that is capable of causing fire throughfriction, absorption or moisture, spontaneous chemicalchange, or retained heat from manufacturing or processing, orwhich has an ignition temperature below 212°F (100°C) orwhich burns so vigorously and persistently when ignited as tocreate a serious hazard. A chemical shall be considered aflammable solid as determined in accordance with the testmethod of CPSC 16 CFR; Part 1500.44, if it ignites and burnswith a self-sustained flame at a rate greater than 0.1 inch (2.5mm) per second along its major axis.

FLAMMABLE VAPOR AREA. An area in which the con-centration of flammable constituents (vapor, gas, fume, mistor dust) in air exceeds 25 percent of their lower flammablelimit (LFL) because of the flammable finish processes opera-tion. It includes:

1. The interior of spray booths.

2. The interior of ducts exhausting from spraying pro-cesses.

3. Any area in the direct path of spray or any area contain-ing dangerous quantities of air-suspended powder,


DEFINITIONS


combustible residue, dust, deposits, vapor or mists as aresult of spraying operations.

4. The area in the vicinity of dip tanks, drain boards orassociated drying, conveying or other equipment duringoperation or shutdown periods.

The building official is authorized to determine the extentof the flammable vapor area, taking into consideration thematerial characteristics of the flammable materials, the degreeof sustained ventilation and the nature of the operations.

[F] FLAMMABLE VAPORS OR FUMES. The concentra-tion of flammable constituents in air that exceed 25 percent oftheir lower flammable limit (LFL).

[F] FLASH POINT. The minimum temperature in degreesFahrenheit at which a liquid will give off sufficient vapors toform an ignitable mixture with air near the surface or in thecontainer, but will not sustain combustion. The flash point ofa liquid shall be determined by appropriate test procedure andapparatus as specified in ASTM D 56, ASTM D 93 or ASTMD 3278.

FLIGHT. A continuous run of rectangular treads, winders orcombination thereof from one landing to another.

FLOOD or FLOODING. A general and temporary condi-tion of partial or complete inundation of normally dry landfrom:

1. The overflow of inland or tidal waters.

2. The unusual and rapid accumulation or runoff of sur-face waters from any source.

FLOOD DAMAGE-RESISTANT MATERIALS. Anyconstruction material capable of withstanding direct and pro-longed contact with floodwaters without sustaining any dam-age that requires more than cosmetic repair.

FLOOD, DESIGN. See “Design flood.”

FLOOD ELEVATION, DESIGN. See “Design flood eleva-tion.”

FLOOD HAZARD AREA. The greater of the following twoareas:

1. The area within a flood plain subject to a 1-percent orgreater chance of flooding in any year.

2. The area designated as a flood hazard area on a com-munity’s flood hazard map, or otherwise legally desig-nated.

FLOOD HAZARD AREAS, SPECIAL. See “Specialflood hazard areas.”

FLOOD HAZARD AREA SUBJECT TO HIGH-VELOCITY WAVE ACTION. Area within the flood haz-ard area that is subject to high-velocity wave action, andshown on a Flood Insurance Rate Map (FIRM) or other floodhazard map as Zone V, VO, VE or V1-30.

FLOOD INSURANCE RATE MAP (FIRM). An officialmap of a community on which the Federal emergency Man-agement Agency (FEMA) has delineated both the specialflood hazard areas and the risk premium zones applicable tothe community.

FLOOD INSURANCE STUDY. The official report pro-vided by the Federal Emergency Management Agency con-taining the Flood Insurance Rate Map (FIRM), the FloodBoundary and Floodway Map (FBFM), the water surface ele-vation of the base flood and supporting technical data.

FLOODWAY. The channel of the river, creek or otherwatercourse and the adjacent land areas that must be reservedin order to discharge the base flood without cumulativelyincreasing the water surface elevation more than a designatedheight.

FLOOR AREA, GROSS. The floor area within the insideperimeter of the exterior walls of the building under consider-ation, exclusive of vent shafts and courts, without deductionfor corridors, stairways, closets, the thickness of interiorwalls, columns or other features. The floor area of a building,or portion thereof, not provided with surrounding exteriorwalls shall be the usable area under the horizontal projectionof the roof or floor above. The gross floor area shall notinclude shafts with no openings or interior courts.

FLOOR AREA, NET. The actual occupied area not includ-ing unoccupied accessory areas such as corridors, stairways,toilet rooms, mechanical rooms and closets.

FLOOR FIRE DOOR ASSEMBLY. A combination of afire door, a frame, hardware and other accessories installed ina horizontal plane, which together provide a specific degreeof fire protection to a through-opening in a fire-resistance-rated floor (see Section 711.8).

[F] FOAM-EXTINGUISHING SYSTEM. A special sys-tem discharging a foam made from concentrates, eithermechanically or chemically, over the area to be protected.

FOAM PLASTIC INSULATION. A plastic that is inten-tionally expanded by the use of a foaming agent to produce areduced-density plastic containing voids consisting of openor closed cells distributed throughout the plastic for thermalinsulating or acoustical purposes and that has a density lessthan 20 pounds per cubic foot (pcf) (320 kg/m3).

FOLDING AND TELESCOPIC SEATING. Tiered seatinghaving an overall shape and size that is capable of beingreduced for purposes of moving or storing and is not a build-ing element.

FOOD COURT. A public seating area located in the mallthat serves adjacent food preparation tenant spaces.

FOSTER CARE FACILITIES. Facilities that provide careto more than five children, 21/2 years of age or less.

FOUNDATION PIER. An isolated vertical foundationmember whose horizontal dimension measured at rightangles to its thickness does not exceed three times its thick-ness and whose height is equal to or less than four times itsthickness.

FRAME STRUCTURE. A building or other structure inwhich vertical loads from floors and roofs are primarily sup-ported by columns.

[F] GAS CABINET. A fully enclosed, ventilated noncom-bustible enclosure used to provide an isolated environmentfor compressed gas cylinders in storage or use. Doors and

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DEFINITIONS


access ports for exchanging cylinders and accessing pressure-regulating controls are allowed to be included.

[F] GAS ROOM. A separately ventilated, fully enclosedroom in which only compressed gases and associated equip-ment and supplies are stored or used.

[F] GASEOUS HYDROGEN SYSTEM. An assembly ofpiping, devices and apparatus designed to generate, store,contain, distribute or transport a nontoxic, gaseous hydrogen-containing mixture having at least 95-percent hydrogen gasby volume and not more than 1-percent oxygen by volume.Gaseous hydrogen systems consist of items such as com-pressed gas containers, reactors and appurtenances, includingpressure regulators, pressure relief devices, manifolds,pumps, compressors and interconnecting piping and tubingand controls.

GLASS FIBERBOARD. Fibrous glass roof insulation con-sisting of inorganic glass fibers formed into rigid boardsusing a binder. The board has a top surface faced with asphaltand kraft reinforced with glass fiber.

GLUED BUILT-UP MEMBER. A structural element, thesection of which is composed of built-up lumber, wood struc-tural panels or wood structural panels in combination withlumber, all parts bonded together with structural adhesives.

GRADE FLOOR OPENING. A window or other openinglocated such that the sill height of the opening is not morethan 44 inches (1118 mm) above or below the finishedground level adjacent to the opening.

GRADE (LUMBER). The classification of lumber in regardto strength and utility in accordance with American SoftwoodLumber Standard DOC PS 20 and the grading rules of anapproved lumber rules-writing agency.

GRADE PLANE. A reference plane representing the aver-age of finished ground level adjoining the building at exteriorwalls. Where the finished ground level slopes away from theexterior walls, the reference plane shall be established by thelowest points within the area between the building and the lotline or, where the lot line is more than 6 feet (1829 mm) fromthe building, between the building and a point 6 feet (1829mm) from the building. For grade of structures built overwater, see Section 425.3.

GRADE PLANE, STORY ABOVE. See “Story abovegrade plane.”

GRANDSTAND. Tiered seating supported on a dedicatedstructural system and two or more rows high and is not abuilding element (see “Bleachers”).

GROSS LEASABLE AREA. The total floor area designedfor tenant occupancy and exclusive use. The area of tenantoccupancy is measured from the centerlines of joint partitionsto the outside of the tenant walls. All tenant areas, includingareas used for storage, shall be included in calculating grossleasable area.

GROUP HOME. A facility for social rehabilitation, sub-stance abuse or mental health problems that contains a grouphousing arrangement that provides custodial care but doesnot provide acute care.

GUARD. A building component or a system of buildingcomponents located at or near the open sides of elevatedwalking surfaces that minimizes the possibility of a fall fromthe walking surface to a lower level.

GYPSUM BOARD. Gypsum wallboard, gypsum sheathing,gypsum base for gypsum veneer plaster, exterior gypsum sof-fit board, predecorated gypsum board or water-resistant gyp-sum backing board complying with the standards listed inTables 2506.2, 2507.2 and Chapter 35.

GYPSUM PLASTER. A mixture of calcined gypsum or cal-cined gypsum and lime and aggregate and other approvedmaterials as specified in this code.

GYPSUM VENEER PLASTER. Gypsum plaster applied toan approved base in one or more coats normally not exceed-ing 1/4 inch (6.4 mm) in total thickness.

HABITABLE SPACE. A space in a building for living,sleeping, eating or cooking. Bathrooms, toilet rooms, closets,halls, storage or utility spaces and similar areas are not con-sidered habitable spaces.

[F] HALOGENATED EXTINGUISHING SYSTEM. Afire-extinguishing system using one or more atoms of an ele-ment from the halogen chemical series: fluorine, chlorine,bromine and iodine.

[F] HANDLING. The deliberate transport by any means to apoint of storage or use.

HANDRAIL. A horizontal or sloping rail intended for grasp-ing by the hand for guidance or support.

HARDBOARD. A fibrous-felted, homogeneous panel madefrom lignocellulosic fibers consolidated under heat and pres-sure in a hot press to a density not less than 31 pcf (497 kg/m3).

[F] HAZARDOUS MATERIALS. Those chemicals or sub-stances that are physical hazards or health hazards as classi-fied in Section 307 and the International Fire Code, whetherthe materials are in usable or waste condition.

[F] HAZARDOUS PRODUCTION MATERIAL (HPM).A solid, liquid or gas associated with semiconductor manu-facturing that has a degree-of-hazard rating in health, flam-mability or instability of Class 3 or 4 as ranked by NFPA 704and which is used directly in research, laboratory or produc-tion processes which have as their end product materials thatare not hazardous.

HEAD JOINT. Vertical mortar joint placed betweenmasonry units within the wythe at the time the masonry unitsare laid.

[F] HEALTH HAZARD. A classification of a chemical forwhich there is statistically significant evidence that acute orchronic health effects are capable of occurring in exposedpersons. The term “health hazard” includes chemicals that aretoxic or highly toxic, and corrosive.

HEAT DETECTOR. See “Detector, heat.”

HEIGHT, BUILDING. The vertical distance from gradeplane to the average height of the highest roof surface otherthan rooftop structures complying with Section 1509.

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DEFINITIONS


HELICAL PILE. Manufactured steel deep foundation ele-ment consisting of a central shaft and one or more helicalbearing plates. A helical pile is installed by rotating it into theground. Each helical bearing plate is formed into a screwthread with a uniform defined pitch.

HELIPAD. A structural surface that is used for the landing,taking off, taxiing and parking of helicopters.

HELIPORT. An area of land or water or a structural surfacethat is used, or intended for the use, for the landing and takingoff of helicopters, and any appurtenant areas that are used, orintended for use, for heliport buildings or other heliport facil-ities.

HELISTOP. The same as “heliport,” except that no fueling,defueling, maintenance, repairs or storage of helicopters ispermitted.

HIGH-PRESSURE DECORATIVE EXTERIOR-GRADECOMPACT LAMINATE (HPL). Panels consisting of layersof cellulose fibrous material impregnated with thermosettingresins and bonded together by a high-pressure process to forma homogeneous nonporous core suitable for exterior use.

HIGH-PRESSURE DECORATIVE EXTERIOR-GRADECOMPACT LAMINATE (HPL) SYSTEM. An exteriorwall covering fabricated using HPL in a specific assemblyincluding joints, seams, attachments, substrate, framing andother details as appropriate to a particular design.

HIGH-RISE BUILDING. A building with an occupied floorlocated more than 75 feet (22 860 mm) above the lowest levelof fire department vehicle access.

[F] HIGHLY TOXIC. A material which produces a lethaldose or lethal concentration that falls within any of the fol-lowing categories:

1. A chemical that has a median lethal dose (LD50) of 50milligrams or less per kilogram of body weight whenadministered orally to albino rats weighing between200 and 300 grams each.

2. A chemical that has a median lethal dose (LD50) of 200milligrams or less per kilogram of body weight whenadministered by continuous contact for 24 hours (orless if death occurs within 24 hours) with the bare skinof albino rabbits weighing between 2 and 3 kilogramseach.

3. A chemical that has a median lethal concentration(LC50) in air of 200 parts per million by volume or lessof gas or vapor, or 2 milligrams per liter or less of mist,fume or dust, when administered by continuous inhala-tion for 1 hour (or less if death occurs within 1 hour) toalbino rats weighing between 200 and 300 grams each.

Mixtures of these materials with ordinary materials, suchas water, might not warrant classification as highly toxic.While this system is basically simple in application, any haz-ard evaluation that is required for the precise categorizationof this type of material shall be performed by experienced,technically competent persons.

HISTORIC BUILDINGS. ((Buildings that are listed in oreligible for listing in the National Register of Historic Places,

or designated as historic under an appropriate state or locallaw (see Sections 3409 and 3411.9).)) See “LANDMARK.”

HORIZONTAL ASSEMBLY. A fire-resistance-rated flooror roof assembly of materials designed to restrict the spreadof fire in which continuity is maintained.

HORIZONTAL EXIT. See “Exit, horizontal.”

[W] HOSPICE CARE CENTER. A building or portionthereof used on a 24-hour basis for the provision of hospiceservices to terminally ill inpatients.

HOSPITALS AND PSYCHIATRIC HOSPITALS. Facili-ties that provide care or treatment for the medical, psychiat-ric, obstetrical, or surgical treatment of care recipients thatare incapable of self-preservation.

HOUSING UNIT. A dormitory or a group of cells with acommon dayroom in Group I-3.

[F] HPM FLAMMABLE LIQUID. An HPM liquid that isdefined as either a Class I flammable liquid or a Class II orClass IIIA combustible liquid.

[F] HPM ROOM. A room used in conjunction with or serv-ing a Group H-5 occupancy, where HPM is stored or usedand which is classified as a Group H-2, H-3 or H-4 occu-pancy.

HURRICANE-PRONE REGIONS. Areas vulnerable tohurricanes defined as:

1. The U.S. Atlantic Ocean and Gulf of Mexico coastswhere the ultimate design wind speed, Vult, for Risk Cat-egory II buildings is greater than 115 mph (51.4 m/s);and

2. Hawaii, Puerto Rico, Guam, Virgin Islands and Ameri-can Samoa.

[F] HYDROGEN CUTOFF ROOM. A room or space thatis intended exclusively to house a gaseous hydrogen system.

ICE-SENSITIVE STRUCTURE. A structure for which theeffect of an atmospheric ice load governs the design of astructure or portion thereof. This includes, but is not limitedto, lattice structures, guyed masts, overhead lines, light sus-pension and cable-stayed bridges, aerial cable systems (e.g.,for ski lifts or logging operations), amusement rides, opencatwalks and platforms, flagpoles and signs.

[F] IMMEDIATELY DANGEROUS TO LIFE ANDHEALTH (IDLH). The concentration of air-borne contami-nants which poses a threat of death, immediate or delayedpermanent adverse health effects, or effects that could pre-vent escape from such an environment. This contaminantconcentration level is established by the National Institute ofOccupational Safety and Health (NIOSH) based on both tox-icity and flammability. It generally is expressed in parts permillion by volume (ppmv/v) or milligrams per cubic meter(mg/m3). If adequate data do not exist for precise establish-ment of IDLH concentrations, an independent certified indus-trial hygienist, industrial toxicologist, appropriate regulatoryagency or other source approved by the building official shallmake such determination.

IMPACT LOAD. The load resulting from moving machin-ery, elevators, craneways, vehicles and other similar forces


DEFINITIONS


and kinetic loads, pressure and possible surcharge from fixedor moving loads.

INCAPABLE OF SELF-PRESERVATION. Personsbecause of age, physical limitations, mental limitations,chemical dependency, or medical treatment who cannotrespond as an individual to an emergency situation.

[F] INCOMPATIBLE MATERIALS. Materials that, whenmixed, have the potential to react in a manner that generatesheat, fumes, gases or byproducts which are hazardous to lifeor property.

[F] INERT GAS. A gas that is capable of reacting with othermaterials only under abnormal conditions such as high tem-peratures, pressures and similar extrinsic physical forces.Within the context of the code, inert gases do not exhibiteither physical or health hazard properties as defined (otherthan acting as a simple asphyxiant) or hazard properties otherthan those of a compressed gas. Some of the more commoninert gases include argon, helium, krypton, neon, nitrogenand xenon.

[F] INITIATING DEVICE. A system component that origi-nates transmission of a change-of-state condition, such as in asmoke detector, manual fire alarm box or supervisory switch.

INSPECTION CERTIFICATE. An identification appliedon a product by an approved agency containing the name ofthe manufacturer, the function and performance characteris-tics, and the name and identification of an approved agencythat indicates that the product or material has been inspectedand evaluated by an approved agency (see Section 1703.5and “Label,” “Manufacturer’s designation” and “Mark”).

INTENDED TO BE OCCUPIED AS A RESIDENCE.This refers to a dwelling unit or sleeping unit that can or willbe used all or part of the time as the occupant’s place ofabode.

INTERIOR EXIT RAMP. An exit component that serves tomeet one or more means of egress design requirements, suchas required number of exits or exit access travel distance, andprovides for a protected path of egress travel to the exit dis-charge or public way.

INTERIOR EXIT STAIRWAY. An exit component thatserves to meet one or more means of egress design require-ments, such as required number of exits or exit access traveldistance, and provides for a protected path of egress travel tothe exit discharge or public way.

INTERIOR FINISH. Interior finish includes interior walland ceiling finish and interior floor finish.

INTERIOR FLOOR FINISH. The exposed floor surfacesof buildings including coverings applied over a finished flooror stair, including risers.

INTERIOR FLOOR-WALL BASE. Interior floor finishtrim used to provide a functional or decorative border at theintersection of walls and floors.

INTERIOR SURFACES. Surfaces other than weatherexposed surfaces.

INTERIOR WALL AND CEILING FINISH. The exposedinterior surfaces of buildings, including but not limited to:fixed or movable walls and partitions; toilet room privacy

partitions; columns; ceilings; and interior wainscoting, panel-ing or other finish applied structurally or for decoration,acoustical correction, surface insulation, structural fire resis-tance or similar purposes, but not including trim.

INTERLAYMENT. A layer of felt or nonbituminous satu-rated felt not less than 18 inches (457 mm) wide, shingledbetween each course of a wood-shake roof covering.

INTUMESCENT FIRE-RESISTANT COATINGS. Thinfilm liquid mixture applied to substrates by brush, roller,spray or trowel which expands into a protective foamed layerto provide fire-resistant protection of the substrates whenexposed to flame or intense heat.

JOINT. The opening in or between adjacent assemblies thatis created due to building tolerances, or is designed to allowindependent movement of the building in any plane causedby thermal, seismic, wind or any other loading.

(([A] JURISDICTION. The governmental unit that hasadopted this code under due legislative authority.))

L RATING. The air leakage rating of a through penetrationfirestop system or a fire-resistant joint system when tested inaccordance with UL 1479 or UL 2079, respectively.

[A] LABEL. An identification applied on a product by themanufacturer that contains the name of the manufacturer, thefunction and performance characteristics of the product ormaterial, and the name and identification of an approvedagency and that indicates that the representative sample of theproduct or material has been tested and evaluated by anapproved agency (see Section 1703.5 and “Inspection certifi-cate,” “Manufacturer’s designation” and “Mark”).

[A] LABELED. Equipment, materials or products to whichhas been affixed a label, seal, symbol or other identifyingmark of a nationally recognized testing laboratory, inspectionagency or other organization concerned with product evalua-tion that maintains periodic inspection of the production ofthe above-labeled items and whose labeling indicates eitherthat the equipment, material or product meets identified stan-dards or has been tested and found suitable for a specifiedpurpose.

LAND-DISTURBING ACTIVITY. Any activity thatresults in a movement of earth, or a change in the existing soilcover (both vegetative and nonvegetative) or the existingtopography. Land-disturbing activities include, but are notlimited to, clearing, grading, filling, excavation or addition orreplacement of impervious surface.

LANDMARK. A building or structure that is subject to arequirement to obtain a certificate of approval from the CityLandmarks Preservation Board before altering or making sig-nificant changes to specific features or characteristics, thathas been nominated for designation and the City LandmarksPreservation Board has not issued a determination regardingdesignation, that has been designated for preservation by theCity Landmarks Preservation Board, that has been designatedfor preservation by the State of Washington, that has beenlisted or determined eligible to be listed in the National Reg-ister of Historic Places, or that is located in a landmark orspecial review district subject to a requirement to obtain a


DEFINITIONS


certificate of approval before making a change to the externalappearance of a structure.

LAND USE CODE. Seattle Land Use Code, Title 23 of theSeattle Municipal Code, as amended.

LEVEL OF EXIT DISCHARGE. See “Exit discharge,level of.”

LIGHT-DIFFUSING SYSTEM. Construction consisting inwhole or in part of lenses, panels, grids or baffles made withlight-transmitting plastics positioned below independentlymounted electrical light sources, skylights or light-transmit-ting plastic roof panels. Lenses, panels, grids and baffles thatare part of an electrical fixture shall not be considered as alight-diffusing system.

LIGHT-FRAME CONSTRUCTION. A type of construc-tion whose vertical and horizontal structural elements are pri-marily formed by a system of repetitive wood or cold-formedsteel framing members.

LIGHT-TRANSMITTING PLASTIC ROOF PANELS.Structural plastic panels other than skylights that are fastenedto structural members, or panels or sheathing and that areused as light-transmitting media in the plane of the roof.

LIGHT-TRANSMITTING PLASTIC WALL PANELS.Plastic materials that are fastened to structural members, or tostructural panels or sheathing, and that are used as light-trans-mitting media in exterior walls.

LIMITED SPRAYING SPACE. An area in which opera-tions for touch-up or spot painting of a surface area of 9square feet (0.84 m2) or less are conducted.

LIMIT STATE. A condition beyond which a structure ormember becomes unfit for service and is judged to be no lon-ger useful for its intended function (serviceability limit state)or to be unsafe (strength limit state).

[F] LIQUID. A material that has a melting point that is equalto or less than 68°F (20°C) and a boiling point that is greaterthan 68°F (20°C) at 14.7 pounds per square inch absolute(psia) (101 kPa). When not otherwise identified, the term“liquid” includes both flammable and combustible liquids.

[F] LIQUID STORAGE ROOM. A room classified as aGroup H-3 occupancy used for the storage of flammable orcombustible liquids in a closed condition.

[F] LIQUID USE, DISPENSING AND MIXING ROOM.A room in which Class I, II and IIIA flammable or combusti-ble liquids are used, dispensed or mixed in open containers.

[A] LISTED. Equipment, materials, products or servicesincluded in a list published by an organization acceptable tothe building official and concerned with evaluation of prod-ucts or services that maintains periodic inspection of produc-tion of listed equipment or materials or periodic evaluation ofservices and whose listing states either that the equipment,material, product or service meets identified standards or hasbeen tested and found suitable for a specified purpose.

LIVE/WORK UNIT. A dwelling unit or sleeping unit inwhich a significant portion of the space includes a nonresi-dential use that is operated by the tenant.

LIVE LOAD. A load produced by the use and occupancy ofthe building or other structure that does not include construc-tion or environmental loads such as wind load, snow load,rain load, earthquake load, flood load or dead load.

LIVE LOAD, ROOF. A load on a roof produced:

1. During maintenance by workers, equipment and mate-rials;

2. During the life of the structure by movable objects suchas planters or other similar small decorative appurte-nances that are not occupancy related; or

3. By the use and occupancy of the roof such as for roofgardens or assembly areas.

LOAD AND RESISTANCE FACTOR DESIGN (LRFD).A method of proportioning structural members and their con-nections using load and resistance factors such that no appli-cable limit state is reached when the structure is subjected toappropriate load combinations. The term “LRFD” is used inthe design of steel and wood structures.

LOAD EFFECTS. Forces and deformations produced instructural members by the applied loads.

LOAD FACTOR. A factor that accounts for deviations ofthe actual load from the nominal load, for uncertainties in theanalysis that transforms the load into a load effect, and for theprobability that more than one extreme load will occur simul-taneously.

LOADS. Forces or other actions that result from the weightof building materials, occupants and their possessions, envi-ronmental effects, differential movement and restraineddimensional changes. Permanent loads are those loads inwhich variations over time are rare or of small magnitude,such as dead loads. All other loads are variable loads (seealso “Nominal loads”).

[A] LOT. A portion or parcel of land considered as a unit.

[A] LOT LINE. A line dividing one lot from another, orfrom a street or any public place.

[F] LOWER FLAMMABLE LIMIT (LFL). The minimumconcentration of vapor in air at which propagation of flamewill occur in the presence of an ignition source. The LFL issometimes referred to as “LEL” or “lower explosive limit.”

LOWEST FLOOR. The floor of the lowest enclosed area,including basement, but excluding any unfinished or flood-resistant enclosure, usable solely for vehicle parking, build-ing access or limited storage provided that such enclosure isnot built so as to render the structure in violation of Section1612.

MAILBOXES. Receptacles for the receipt of documents,packages or other deliverable matter. Mailboxes include, butare not limited to, post office boxes and receptacles providedby commercial mail-receiving agencies, apartment housesand schools.

MAIN WINDFORCE-RESISTING SYSTEM. An assem-blage of structural elements assigned to provide support andstability for the overall structure. The system generallyreceives wind loading from more than one surface.


DEFINITIONS


MALL BUILDING, COVERED and MALL BUILDING,OPEN. See “Covered mall building.”

[F] MANUAL FIRE ALARM BOX. A manually operateddevice used to initiate an alarm signal.

[A] MANUFACTURER’S DESIGNATION. An identifica-tion applied on a product by the manufacturer indicating thata product or material complies with a specified standard orset of rules (see also “Inspection certificate,” “Label” and“Mark”).

MARINA. A facility, generally on the waterfront, that storesand services boats in berths, on moorings, and in dry storageor dry stack storage.

[A] MARK. An identification applied on a product by themanufacturer indicating the name of the manufacturer and thefunction of a product or material (see also “Inspection certifi-cate,” “Label” and “Manufacturer’s designation”).

MARQUEE. ((A canopy that has a top surface which issloped less than 25 degrees from the horizontal and is locatedless than 10 feet (3.05 m) from operable openings above oradjacent to the level of the marquee.)) Marquees are a type ofcanopy. See “canopy.”

MASONRY. A built-up construction or combination ofbuilding units or materials of clay, shale, concrete, glass, gyp-sum, stone or other approved units bonded together with orwithout mortar or grout or other accepted methods of joining.

Ashlar masonry. Masonry composed of various-sizedrectangular units having sawed, dressed or squared bedsurfaces, properly bonded and laid in mortar.

Coursed ashlar. Ashlar masonry laid in courses of stoneof equal height for each course, although different coursesshall be permitted to be of varying height.

Glass unit masonry. Masonry composed of glass unitsbonded by mortar.

Plain masonry. Masonry in which the tensile resistance ofthe masonry is taken into consideration and the effects ofstresses in reinforcement are neglected.

Random ashlar. Ashlar masonry laid in courses of stoneset without continuous joints and laid up without drawnpatterns. When composed of material cut into modularheights, discontinuous but aligned horizontal joints arediscernible.

Reinforced masonry. Masonry construction in whichreinforcement acting in conjunction with the masonry isused to resist forces.

Solid masonry. Masonry consisting of solid masonryunits laid contiguously with the joints between the unitsfilled with mortar.

Unreinforced (plain) masonry. Masonry in which thetensile resistance of masonry is taken into considerationand the resistance of the reinforcing steel, if present, isneglected.

MASONRY UNIT. Brick, tile, stone, glass block or concreteblock conforming to the requirements specified in Section2103.

Hollow. A masonry unit whose net cross-sectional area inany plane parallel to the load-bearing surface is less than75 percent of its gross cross-sectional area measured inthe same plane.

Solid. A masonry unit whose net cross-sectional area inevery plane parallel to the load-bearing surface is 75 per-cent or more of its gross cross-sectional area measured inthe same plane.

MASTIC FIRE-RESISTANT COATINGS. Liquid mix-ture applied to a substrate by brush, roller, spray or trowelthat provides fire-resistant protection of a substrate whenexposed to flame or intense heat.

MEANS OF EGRESS. A continuous and unobstructed pathof vertical and horizontal egress travel from any occupiedportion of a building or structure to a public way. A means ofegress consists of three separate and distinct parts: the exitaccess, the exit and the exit discharge.

MECHANICAL-ACCESS OPEN PARKING GARAGES.Open parking garages employing parking machines, lifts,elevators or other mechanical devices for vehicles movingfrom and to street level and in which public occupancy is pro-hibited above the street level.

MECHANICAL EQUIPMENT SCREEN. A rooftop struc-ture, not covered by a roof, used to aesthetically concealplumbing, electrical or mechanical equipment from view.

MECHANICAL SYSTEMS. For the purposes of determin-ing seismic loads in ASCE 7, mechanical systems shallinclude plumbing systems as specified therein.

MEDICAL CARE. Care involving medical or surgical pro-cedures, nursing or for psychiatric purposes.

MEMBRANE-COVERED CABLE STRUCTURE. Anonpressurized structure in which a mast and cable systemprovides support and tension to the membrane weather bar-rier and the membrane imparts stability to the structure.

MEMBRANE-COVERED FRAME STRUCTURE. Anonpressurized building wherein the structure is composed ofa rigid framework to support a tensioned membrane whichprovides the weather barrier.

MEMBRANE PENETRATION. A breach in one side of afloor-ceiling, roof-ceiling or wall assembly to accommodatean item installed into or passing through the breach.

MEMBRANE-PENETRATION FIRESTOP. A material,device or construction installed to resist for a prescribed timeperiod the passage of flame and heat through openings in aprotective membrane in order to accommodate cables, cabletrays, conduit, tubing, pipes or similar items.

MEMBRANE-PENETRATION FIRESTOP SYSTEM.An assemblage consisting of a fire-resistance-rated floor-ceil-ing, roof-ceiling or wall assembly, one or more penetratingitems installed into or passing through the breach in one sideof the assembly and the materials or devices, or both,installed to resist the spread of fire into the assembly for aprescribed period of time.

MERCHANDISE PAD. A merchandise pad is an area fordisplay of merchandise surrounded by aisles, permanent fix-tures or walls. Merchandise pads contain elements such as�

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DEFINITIONS


nonfixed and moveable fixtures, cases, racks, counters andpartitions as indicated in Section 105.2 from which customersbrowse or shop.

METAL COMPOSITE MATERIAL (MCM). A factory-manufactured panel consisting of metal skins bonded to bothfaces of a plastic core.

METAL COMPOSITE MATERIAL (MCM) SYSTEM. An exterior wall covering fabricated using MCM in a specificassembly including joints, seams, attachments, substrate,framing and other details as appropriate to a particular design.

METAL ROOF PANEL. An interlocking metal sheet hav-ing a minimum installed weather exposure of 3 square feet(0.279 m2) per sheet.

METAL ROOF SHINGLE. An interlocking metal sheethaving an installed weather exposure less than 3 square feet(0.279 m2) per sheet.

MEZZANINE. An intermediate level or levels between thefloor and ceiling of any story and in accordance with Section505.

MICROPILE. A micropile is a bored, grouted-in-place deepfoundation element that develops its load-carrying capacityby means of a bond zone in soil, bedrock or a combination ofsoil and bedrock.

MINERAL BOARD. A rigid felted thermal insulation boardconsisting of either felted mineral fiber or cellular beads ofexpanded aggregate formed into flat rectangular units.

MINERAL FIBER. Insulation composed principally offibers manufactured from rock, slag or glass, with or withoutbinders.

MINERAL WOOL. Synthetic vitreous fiber insulationmade by melting predominately igneous rock or furnace slag,and other inorganic materials, and then physically formingthe melt into fibers.

MODIFIED BITUMEN ROOF COVERING. One or morelayers of polymer-modified asphalt sheets. The sheet materi-als shall be fully adhered or mechanically attached to the sub-strate or held in place with an approved ballast layer.

MORTAR. A mixture consisting of cementitious materials,fine aggregates, water, with or without admixtures, that isused to construct unit masonry assemblies.

MORTAR, SURFACE-BONDING. A mixture to bondconcrete masonry units that contains hydraulic cement, glassfiber reinforcement with or without inorganic fillers ororganic modifiers and water.

MULTILEVEL ASSEMBLY SEATING. Seating that isarranged in distinct levels where each level is comprised ofeither multiple rows, or a single row of box seats accessedfrom a separate level.

[F] MULTIPLE-STATION ALARM DEVICE. Two ormore single-station alarm devices that can be interconnectedsuch that actuation of one causes all integral or separate audi-ble alarms to operate. It also can consist of one single-stationalarm device having connections to other detectors or to amanual fire alarm box.

[F] MULTIPLE-STATION SMOKE ALARM. Two ormore single-station alarm devices that are capable of inter-connection such that actuation of one causes the appropriatealarm signal to operate in all interconnected alarms.

MULTISTORY UNIT. A dwelling unit or sleeping unit withhabitable space located on more than one story.

NAILING, BOUNDARY. A special nailing pattern requiredby design at the boundaries of diaphragms.

NAILING, EDGE. A special nailing pattern required bydesign at the edges of each panel within the assembly of adiaphragm or shear wall.

NAILING, FIELD. Nailing required between the sheathingpanels and framing members at locations other than boundarynailing and edge nailing.

NATURALLY DURABLE WOOD. The heartwood of thefollowing species except for the occasional piece with cornersapwood, provided 90 percent or more of the width of eachside on which it occurs is heartwood.

Decay resistant. Redwood, cedar, black locust and blackwalnut.

Termite resistant. Redwood, Alaska yellow cedar, East-ern red cedar and both heartwood and all sapwood ofWestern red cedar.

[W] NIGHTCLUB. An A-2 occupancy under the 2006International Building Code in which the aggregate area ofconcentrated use of unfixed chairs and standing space that isspecifically designated and primarily used for dancing orviewing performers exceeds 350 square feet (33 m2), exclud-ing adjacent lobby areas. “Nightclub” does not include the-aters with fixed seating, banquet halls, or lodge halls.

NOMINAL LOADS. The magnitudes of the loads specifiedin Chapter 16 (dead, live, soil, wind, snow, rain, flood andearthquake).

NOMINAL SIZE (LUMBER). The commercial size desig-nation of width and depth, in standard sawn lumber andglued-laminated lumber grades; somewhat larger than thestandard net size of dressed lumber, in accordance withDOCPS 20 for sawn lumber and with the AF&PA NDS forglued-laminated lumber.

NONCOMBUSTIBLE MEMBRANE STRUCTURE. Amembrane structure in which the membrane and all compo-nent parts of the structure are noncombustible.

NON-PRODUCTION LABORATORY FACILITY. Afacility where the containers used for reactions, transfers, andother handling of chemicals are designed to be easily andsafely manipulated by one person. It is a workplace wherechemicals are used or synthesized on a nonproduction basis.

[W] NONSTRUCTURAL CONCRETE. Any elementmade of plain or reinforced concrete that is not part of a struc-tural system required to transfer either gravity or lateral loadsto the ground.

NONSTRUCTURAL TRIM. The moldings, battens, caps,nailing strips, latticing or cutouts which are attached to thesign structure.


DEFINITIONS


[F] NORMAL TEMPERATURE AND PRESSURE(NTP). A temperature of 70°F (21°C) and a pressure of 1atmosphere [14.7 psia (101 kPa)].

NOSING. The leading edge of treads of stairs and of land-ings at the top of stairway flights.

[F] NOTIFICATION ZONE. See “Zone, notification.”

[F] NUISANCE ALARM. An alarm caused by mechanicalfailure, malfunction, improper installation or lack of propermaintenance, or an alarm activated by a cause that cannot bedetermined.

NURSING HOMES. Facilities that provide care, includingboth intermediate care facilities and skilled nursing facilitieswhere any of the persons are incapable of self-preservation.

OCCUPANT LOAD. The number of persons for which themeans of egress of a building or portion thereof is designed.

OCCUPIABLE SPACE. A room or enclosed spacedesigned for human occupancy in which individuals congre-gate for amusement, educational or similar purposes or inwhich occupants are engaged at labor, and which is equippedwith means of egress and light and ventilation facilities meet-ing the requirements of this code.

OPEN PARKING GARAGE. A structure or portion of astructure with the openings as described in Section 406.5.2 ontwo or more sides that is used for the parking or storage ofprivate motor vehicles as described in Section 406.5.3.

[F] OPEN SYSTEM. The use of a solid or liquid hazardousmaterial involving a vessel or system that is continuouslyopen to the atmosphere during normal operations and wherevapors are liberated, or the product is exposed to the atmo-sphere during normal operations. Examples of open systemsfor solids and liquids include dispensing from or into openbeakers or containers, dip tank and plating tank operations.

[F] OPERATING BUILDING. A building occupied in con-junction with the manufacture, transportation or use of explo-sive materials. Operating buildings are separated from oneanother with the use of intraplant or intraline distances

ORDINARY PRECAST STRUCTURAL WALL. SeeSection 1905.1.1.

ORDINARY REINFORCED CONCRETE STRUC-TURAL WALL. See Section 1905.1.1.

ORDINARY STRUCTURAL PLAIN CONCRETEWALL. See Section 1905.1.1.

[F] ORGANIC PEROXIDE. An organic compound thatcontains the bivalent -O-O- structure and which may be con-sidered to be a structural derivative of hydrogen peroxidewhere one or both of the hydrogen atoms have been replacedby an organic radical. Organic peroxides can pose an explo-sion hazard (detonation or deflagration) or they can be shocksensitive. They can also decompose into various unstablecompounds over an extended period of time.

Class I. Those formulations that are capable of deflagra-tion but not detonation.

Class II. Those formulations that burn very rapidly andthat pose a moderate reactivity hazard.

Class III. Those formulations that burn rapidly and thatpose a moderate reactivity hazard.

Class IV. Those formulations that burn in the same man-ner as ordinary combustibles and that pose a minimal reac-tivity hazard.

Class V. Those formulations that burn with less intensitythan ordinary combustibles or do not sustain combustionand that pose no reactivity hazard.

Unclassified detonable. Organic peroxides that are capa-ble of detonation. These peroxides pose an extremely highexplosion hazard through rapid explosive decomposition.

ORTHOGONAL. To be in two horizontal directions, at 90degrees (1.57 rad) to each other.

OTHER STRUCTURES. Structures, other than buildings,for which loads are specified in Chapter 16.

OUTPATIENT CLINIC. See “Clinic, outpatient.”

[A] OWNER. Any person, agent, firm or corporation havinga legal or equitable interest in the property.

[F] OXIDIZER. A material that readily yields oxygen orother oxidizing gas, or that readily reacts to promote or initi-ate combustion of combustible materials and, if heated orcontaminated, can result in vigorous self-sustained decompo-sition.

Class 4. An oxidizer that can undergo an explosive reac-tion due to contamination or exposure to thermal or physi-cal shock and that causes a severe increase in the burningrate of combustible materials with which it comes intocontact. Additionally, the oxidizer causes a severe increasein the burning rate and can cause spontaneous ignition ofcombustibles.

Class 3. An oxidizer that causes a severe increase in theburning rate of combustible materials with which it comesin contact.

Class 2. An oxidizer that will cause a moderate increase inthe burning rate of combustible materials with which itcomes in contact.

Class 1. An oxidizer that does not moderately increase theburning rate of combustible materials.

[F] OXIDIZING GAS. A gas that can support and acceleratecombustion of other materials more than air does.

PANEL (PART OF A STRUCTURE). The section of afloor, wall or roof comprised between the supporting frame oftwo adjacent rows of columns and girders or column bands offloor or roof construction.

PANIC HARDWARE. A door-latching assembly incorpo-rating a device that releases the latch upon the application ofa force in the direction of egress travel. See also “Fire exithardware.”

PARTICLEBOARD. A generic term for a panel primarilycomposed of cellulosic materials (usually wood), generally inthe form of discrete pieces or particles, as distinguished fromfibers. The cellulosic material is combined with syntheticresin or other suitable bonding system by a process in which

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DEFINITIONS


the interparticle bond is created by the bonding system underheat and pressure.

PENETRATION FIRESTOP. A through-penetration fire-stop or a membrane-penetration firestop.

PENTHOUSE. An enclosed, unoccupied rooftop structureused for sheltering mechanical and electrical equipment,tanks, elevators and related machinery, and vertical shaftopenings.

PERFORMANCE CATEGORY. A designation of woodstructural panels as related to the panel performance used inChapter 23.

[A] PERMIT. An official document or certificate issued bythe authority having jurisdiction which authorizes perfor-mance of a specified activity.

[A] PERSON. An individual, ((heirs, executors, administra-tors or assigns, and also includes a)) receiver, administrator,executor, assignee, trustee in bankruptcy, trust estate, firm,partnership, joint venture, club, company, joint stock com-pany, business trust, municipal corporation, political subdivi-sion of the State of Washington, the State of Washington andany instrumentality thereof, ((or)) corporation, limited liabil-ity company, association, society or any group of individualsacting as a unit, whether mutual, cooperative, fraternal, non-profit or otherwise, and the United States or any instrumental-ity thereof. ((its or their successors or assigns, or the agent ofany of the aforesaid)).

PERSONAL CARE SERVICE. The care of persons who donot require medical care. Personal care involves responsibil-ity for the safety of the persons while inside the building

PHOTOLUMINESCENT. Having the property of emittinglight that continues for a length of time after excitation byvisible or invisible light has been removed.

PHOTOVOLTAIC MODULES/SHINGLES. A roof cov-ering composed of flat-plate photovoltaic modules fabricatedin sheets that resemble three-tab composite shingles.

[F] PHYSICAL HAZARD. A chemical for which there isevidence that it is a combustible liquid, cryogenic fluid,explosive, flammable (solid, liquid or gas), organic peroxide(solid or liquid), oxidizer (solid or liquid), oxidizing gas,pyrophoric (solid, liquid or gas), unstable (reactive) material(solid, liquid or gas) or water-reactive material (solid or liq-uid).

[F] PHYSIOLOGICAL WARNING THRESHOLDLEVEL. A concentration of air-borne contaminants, nor-mally expressed in parts per million (ppm) or milligrams percubic meter (mg/m3), that represents the concentration atwhich persons can sense the presence of the contaminant dueto odor, irritation or other quick-acting physiologicalresponse. When used in conjunction with the permissibleexposure limit (PEL) the physiological warning thresholdlevels are those consistent with the classification system usedto establish the PEL. See the definition of “Permissible expo-sure limit (PEL)” in the International Fire Code.

PIER. A structure, usually of greater length than width, oftimber, stone, concrete or other material, having a deck andprojecting from the shore into waters so that boats may be

moored alongside for loading, unloading, storage, repairs orcommercial uses.

PLACE OF RELIGIOUS WORSHIP. See “Religious wor-ship, place of.”

PLASTIC, APPROVED. Any thermoplastic, thermosettingor reinforced thermosetting plastic material that conforms tocombustibility classifications specified in the section applica-ble to the application and plastic type.

PLASTIC GLAZING. Plastic materials that are glazed orset in frame or sash and not held by mechanical fasteners thatpass through the glazing material.

PLATFORM. A raised area within a building used for wor-ship, the presentation of music, plays or other entertainment;the head table for special guests; the raised area for lecturersand speakers; boxing and wrestling rings; theater-in-the-round stages; and similar purposes wherein there are no over-head hanging curtains, drops, scenery or stage effects otherthan lighting and sound. A temporary platform is oneinstalled for not more than 30 days.

POLYPROPYLENE SIDING. A shaped material, madeprincipally from polypropylene homopolymer, or copolymer,which in some cases contains fillers or reinforcements, that isused to clad exterior walls of buildings.

PORCELAIN TILE. Porcelain tile shall conform to therequirements of ANSI 137.1.3 for ceramic tile having anabsorption of 0.5 percent or less according to ANSI 137.4.1–Class Table and ANSI 137.1.6.1 Allowable Properties by TileType–Table 10.

[W] PORTABLE SCHOOL CLASSROOM. A structure,transportable in one or more sections, that requires a chassisto be transported, and is designed to be used as an educationalspace with or without a permanent foundation. The structureshall be trailerable and capable of being demounted and relo-cated to other locations as needs arise.

POSITIVE ROOF DRAINAGE. The drainage condition inwhich consideration has been made for all loading deflectionsof the roof deck, and additional slope has been provided toensure drainage of the roof within 48 hours of precipitation.

PREFABRICATED WOOD I-JOIST. Structural membermanufactured using sawn or structural composite lumberflanges and wood structural panel webs bonded together withexterior exposure adhesives, which forms an “I” cross-sec-tional shape.

PRESTRESSED MASONRY. Masonry in which internalstresses have been introduced to counteract potential tensilestresses in masonry resulting from applied loads.

PRIMARY FUNCTION. A primary function is a majoractivity for which the facility is intended. Areas that contain aprimary function include, but are not limited to, the customerservice lobby of a bank, the dining area of a cafeteria, themeeting rooms in a conference center, as well as offices andother work areas in which the activities of the public accom-modation or other private entity using the facility are carriedout. Mechanical rooms, boiler rooms, supply storage rooms,employee lounges or locker rooms, janitorial closets,

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DEFINITIONS


entrances, corridors and restrooms are not areas containing aprimary function.

PRIMARY STRUCTURAL FRAME. The primary struc-tural frame shall include all of the following structural mem-bers:

1. The columns;

2. Structural members having direct connections to thecolumns, including girders, beams, trusses and span-drels;

3. Members of the floor construction and roof construc-tion having direct connections to the columns; and

4. Bracing members that are essential to the vertical sta-bility of the primary structural frame under gravityloading shall be considered part of the primary struc-tural frame whether or not the bracing member carriesgravity loads.

PRISM. An assemblage of masonry units and mortar with orwithout grout used as a test specimen for determining proper-ties of the masonry.

PRIVATE TRANSFORMER VAULT. Vaults that containtransformer equipment that is not owned by Seattle CityLight or other electric power utility.

PROJECTING SIGN. A sign other than a wall sign, whichprojects from and is supported by a wall of a building orstructure.

PROSCENIUM WALL. The wall that separates the stagefrom the auditorium or assembly seating area.

PSYCHIATRIC HOSPITALS. See “Hospitals.”

PUBLIC ENTRANCE. An entrance that is not a serviceentrance or a restricted entrance.

PUBLIC-USE AREAS. Interior or exterior rooms or spacesthat are made available to the general public.

[A] PUBLIC WAY. A street, alley or other parcel of landopen to the outside air leading to a street, that has beendeeded, dedicated or otherwise permanently appropriated tothe public for public use and which has a clear width andheight of not less than 10 feet (3048 mm).

[F] PYROPHORIC. A chemical with an auto-ignition tem-perature in air, at or below a temperature of 130°F (54.4°C).

[F] PYROTECHNIC COMPOSITION. A chemical mix-ture that produces visible light displays or sounds through aself-propagating, heat-releasing chemical reaction which isinitiated by ignition.

RAMP. A walking surface that has a running slope steeperthan one unit vertical in 20 units horizontal (5-percent slope).

RAMP-ACCESS OPEN PARKING GARAGES. Openparking garages employing a series of continuously risingfloors or a series of interconnecting ramps between floorspermitting the movement of vehicles under their own powerfrom and to the street level.

[F] RECORD DRAWINGS. Drawings (“as builts”) thatdocument the location of all devices, appliances, wiringsequences, wiring methods and connections of the compo-nents of a fire alarm system as installed.

RECYCLABLE MATERIALS. Those solid wastes that areseparated for recycling or reuse, such as papers, metals andglass.

REFLECTIVE PLASTIC CORE FOIL INSULATION.An insulation material packaged in rolls, that is less than 0.5inches thick, with at least one exterior low emittance surface(0.1 or less) and a core material containing voids or cells.

[A] REGISTERED DESIGN PROFESSIONAL. An indi-vidual who is registered or licensed to practice their respec-tive design profession as defined by the statutoryrequirements of the professional registration laws of the stateor jurisdiction in which the project is to be constructed.

[A] REGISTERED DESIGN PROFESSIONAL INRESPONSIBLE CHARGE. A registered design profes-sional engaged by the owner to review and coordinate certainaspects of the project, as determined by the building official,for compatibility with the design of the building or structure,including submittal documents prepared by others, deferredsubmittal documents and phased submittal documents.

RELIGIOUS WORSHIP, PLACE OF. A building or por-tion thereof intended for the performance of religious ser-vices.

(([A] REPAIR. The reconstruction or renewal of any part ofan existing building for the purpose of its maintenance.))

REROOFING. The process of recovering or replacing anexisting roof covering. See “Roof recover” and “Roofreplacement.”

RESIDENTIAL AIRCRAFT HANGAR. An accessorybuilding less than 2,000 square feet (186 m2) and 20 feet(6096 mm) in building height constructed on a one- or two-family property where aircraft are stored. Such use will beconsidered as a residential accessory use incidental to thedwelling.

RESISTANCE FACTOR. A factor that accounts for devia-tions of the actual strength from the nominal strength and themanner and consequences of failure (also called “strengthreduction factor”).

RESTRICTED ENTRANCE. An entrance that is madeavailable for common use on a controlled basis, but not publicuse, and that is not a service entrance.

((RETRACTABLE AWNING. A retractable awning is acover with a frame that retracts against a building or otherstructure to which it is entirely supported.))

RISK CATEGORY. A categorization of buildings and otherstructures for determination of flood, wind, snow, ice andearthquake loads based on the risk associated with unaccept-able performance.

RISK-TARGETED MAXIMUM CONSIDERED EARTH-QUAKE (MCER) GROUND MOTION RESPONSEACCELERATIONS. The most severe earthquake effects con-sidered by this code, determined for the orientation that results inthe largest maximum response to horizontal ground motions andwith adjustment for targeted risk.

ROOF ASSEMBLY (For application to Chapter 15 only).A system designed to provide weather protection and resis-tance to design loads. The system consists of a roof covering

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DEFINITIONS


and roof deck or a single component serving as both the roofcovering and the roof deck. A roof assembly includes the roofdeck, vapor retarder, substrate or thermal barrier, insulation,vapor retarder and roof covering.

ROOF COVERING. The covering applied to the roof deckfor weather resistance, fire classification or appearance.

ROOF COVERING SYSTEM. See “Roof assembly.”

ROOF DECK. The flat or sloped surface constructed on topof the exterior walls of a building or other supports for thepurpose of enclosing the story below, or sheltering an area, toprotect it from the elements, not including its supportingmembers or vertical supports.

ROOF DRAINAGE, POSITIVE. See “Positive roof drain-age.”

ROOF RECOVER. The process of installing an additionalroof covering over a prepared existing roof covering withoutremoving the existing roof covering.

ROOF REPAIR. Reconstruction or renewal of any part ofan existing roof for the purposes of its maintenance.

ROOF REPLACEMENT. The process of removing theexisting roof covering, repairing any damaged substrate andinstalling a new roof covering.

ROOF SIGN. A sign erected upon or above a roof or parapetof a building or structure.

ROOF VENTILATION. The natural or mechanical processof supplying conditioned or unconditioned air to, or removingsuch air from, attics, cathedral ceilings or other enclosedspaces over which a roof assembly is installed.

ROOFTOP STRUCTURE. A structure erected on top of theroof deck or on top of any part of a building.

RUBBLE MASONRY. Masonry composed of roughlyshaped stones.

Coursed rubble. Masonry composed of roughly shapedstones fitting approximately on level beds and wellbonded.

Random rubble. Masonry composed of roughly shapedstones laid without regularity of coursing but well bondedand fitted together to form well-divided joints.

Rough or ordinary rubble. Masonry composed ofunsquared field stones laid without regularity of coursingbut well bonded.

RUNNING BOND. The placement of masonry units suchthat head joints in successive courses are horizontally offsetat least one-quarter the unit length.

SALLYPORT. A security vestibule with two or more doorsor gates where the intended purpose is to prevent continuousand unobstructed passage by allowing the release of only onedoor or gate at a time.

SCISSOR STAIR. Two interlocking stairways providingtwo separate paths of egress located within one stairwellenclosure.

SCUPPER. An opening in a wall or parapet that allows waterto drain from a roof.

SECONDARY MEMBERS. The following structural mem-bers shall be considered secondary members and not part ofthe primary structural frame:

1. Structural members not having direct connections tothe columns;

2. Members of the floor construction and roof construc-tion not having direct connections to the columns; and

3. Bracing members other than those that are part of theprimary structural frame.

SEISMIC DESIGN CATEGORY. A classificationassigned to a structure based on its risk category and theseverity of the design earthquake ground motion at the site.

SEISMIC FORCE-RESISTING SYSTEM. That part ofthe structural system that has been considered in the design toprovide the required resistance to the prescribed seismicforces.

SELF-CLOSING. As applied to a fire door or other openingprotective, means equipped with an device that will ensureclosing after having been opened.

SELF-LUMINOUS. Illuminated by a self-contained powersource, other than batteries, and operated independently ofexternal power sources.

SELF-PRESERVATION, INCAPABLE OF. See “Incapa-ble of self-preservation.”

SELF-SERVICE STORAGE FACILITY. Real propertydesigned and used for the purpose of renting or leasing indi-vidual storage spaces to customers for the purpose of storingand removing personal property on a self-service basis.

[F] SERVICE CORRIDOR. A fully enclosed passage usedfor transporting HPM and purposes other than requiredmeans of egress.

SERVICE ENTRANCE. An entrance intended primarily fordelivery of goods or services.

SHAFT. An enclosed space extending through one or morestories of a building, connecting vertical openings in succes-sive floors, or floors and roof.

SHAFT ENCLOSURE. The walls or construction formingthe boundaries of a shaft.

SHALLOW FOUNDATION. A shallow foundation is anindividual or strip footing, a mat foundation, a slab-on-gradefoundation or a similar foundation element.

Interpretation I202S: A secondary member (componentor subsystem) is a structurally significant portion of thebuilding that is supported by the primary structural frame,but which does not contribute to the strength or stability ofthe primary structure. Secondary members have internalstructural integrity to perform their function and have theirinteractions with and attachments to the primary structuralframe analyzed and designed to assure proper integrationwithin the total structure.


DEFINITIONS


SHEAR WALL (For Chapter 23). A wall designed to resistlateral forces parallel to the plane of a wall.

Shear wall, perforated. A wood structural panel sheathedwall with openings, that has not been specifically designedand detailed for force transfer around openings.

Shear wall segment, perforated. A section of shear wallwith full-height sheathing that meets the height-to-widthratio limits of Section 4.3.4 of AF&PA SDPWS.

SHEAR WALL (For Chapter 21).

Detailed plain masonry shear wall. A masonry shearwall designed to resist lateral forces neglecting stresses inreinforcement, and designed in accordance with Section2106.1.

Intermediate prestressed masonry shear wall. A pre-stressed masonry shear wall designed to resist lateralforces considering stresses in reinforcement, and designedin accordance with Section 2106.1.

Intermediate reinforced masonry shear wall. Amasonry shear wall designed to resist lateral forces consid-ering stresses in reinforcement, and designed in accor-dance with Section 2106.1.

Ordinary plain masonry shear wall. A masonry shearwall designed to resist lateral forces neglecting stresses inreinforcement, and designed in accordance with Section2106.1.

Ordinary plain prestressed masonry shear wall. A pre-stressed masonry shear wall designed to resist lateralforces considering stresses in reinforcement, and designedin accordance with Section 2106.1.

Ordinary reinforced masonry shear wall. A masonryshear wall designed to resist lateral forces consideringstresses in reinforcement, and designed in accordance withSection 2106.1.

Special prestressed masonry shear wall. A prestressedmasonry shear wall designed to resist lateral forces consid-ering stresses in reinforcement and designed in accordancewith Section 2106.1 except that only grouted, laterallyrestrained tendons are used.

Special reinforced masonry shear wall. A masonryshear wall designed to resist lateral forces consideringstresses in reinforcement, and designed in accordance withSection 2106.1.

SINGLE-PLY MEMBRANE. A roofing membrane that isfield applied using one layer of membrane material (eitherhomogeneous or composite) rather than multiple layers.

[F] SINGLE-STATION SMOKE ALARM. An assemblyincorporating the detector, the control equipment and thealarm-sounding device in one unit, operated from a powersupply either in the unit or obtained at the point of installa-tion.

SITE. A parcel of land bounded by a lot line or a designatedportion of a public right-of-way.

SITE CLASS. A classification assigned to a site based on thetypes of soils present and their engineering properties asdefined in Section 1613.3.2.

SITE COEFFICIENTS. The values of Fa and Fv indicatedin Tables 1613.3.3(1) and 1613.3.3(2), respectively.

SITE-FABRICATED STRETCH SYSTEM. A system,fabricated on site and intended for acoustical, tackable or aes-thetic purposes, that is comprised of three elements:

1. A frame (constructed of plastic, wood, metal or othermaterial) used to hold fabric in place,

2. A core material (infill, with the correct properties forthe application), and

3. An outside layer, comprised of a textile, fabric or vinyl,that is stretched taut and held in place by tension ormechanical fasteners via the frame.

SKYLIGHT, UNIT. A factory-assembled, glazed fenestra-tion unit, containing one panel of glazing material that allowsfor natural lighting through an opening in the roof assemblywhile preserving the weather-resistant barrier of the roof.

SKYLIGHTS AND SLOPED GLAZING. Glass or othertransparent or translucent glazing material installed at a slopeof 15 degrees (0.26 rad) or more from vertical. Glazing mate-rial in skylights, including unit skylights, solariums, sun-rooms, roofs and sloped walls, are included in this definition.

SLEEPING UNIT. A room or space in which people sleep,which can also include permanent provisions for living, eat-ing, and either sanitation or kitchen facilities but not both.Such rooms and spaces that are also part of a dwelling unitare not sleeping units.

SLIP. A berthing space between or adjacent to piers,wharves, or docks; the water areas associated with boat moor-age.

[W] SMALL BUSINESS. Any business entity (including asole proprietorship, corporation, partnership or other legalentity) which is owned and operated independently from allother businesses, which has the purpose of making a profit,and which has 50 or fewer employees.

[F] SMOKE ALARM. A single- or multiple-station alarmresponsive to smoke. See also definitions of “Multiple-sta-tion smoke alarm” and “Single station smoke alarm.”

SMOKE BARRIER. A continuous membrane, either verti-cal or horizontal, such as a wall, floor or ceiling assembly,that is designed and constructed to restrict the movement ofsmoke.

SMOKE COMPARTMENT. A space within a buildingenclosed by smoke barriers on all sides, including the top andbottom.

SMOKE DAMPER. A listed device installed in ducts andair transfer openings designed to resist the passage of smoke.The device is installed to operate automatically, controlled bya smoke detection system, and where required, is capable ofbeing positioned from a fire command center.

[F] SMOKE DETECTOR. A listed device that senses visi-ble or invisible particles of combustion.

SMOKE-DEVELOPED INDEX. A comparative measure,expressed as a dimensionless number, derived from measure-ments of smoke obscuration versus time for a material testedin accordance with ASTM E 84.

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DEFINITIONS


SMOKE-PROTECTED ASSEMBLY SEATING. Seatingserved by means of egress that is not subject to smoke accu-mulation within or under a structure.

SMOKEPROOF ENCLOSURE. An exit stairway designedand constructed so that the movement of the products of com-bustion produced by a fire occurring in any part of the build-ing into the enclosure is limited.

[F] SOLID. A material that has a melting point, decomposesor sublimes at a temperature greater than 68°F (20°C).

SPECIAL AMUSEMENT BUILDING. A special amuse-ment building is any temporary or permanent building or por-tion thereof that is occupied for amusement, entertainment oreducational purposes and that contains a device or systemthat conveys passengers or provides a walkway along, aroundor over a course in any direction so arranged that the means ofegress path is not readily apparent due to visual or audio dis-tractions or is intentionally confounded or is not readily avail-able because of the nature of the attraction or mode ofconveyance through the building or structure.

SPECIAL FLOOD HAZARD AREA. The land area sub-ject to flood hazards and shown on a Flood Insurance RateMap or other flood hazard map as Zone A, AE, A1-30, A99,AR, AO, AH, V, VO, VE or V1-30.

SPECIAL INSPECTION. Inspection of construction requir-ing the expertise of an approved special inspector in order toensure compliance with this code and the approved construc-tion documents.

Continuous special inspection. Special inspection by thespecial inspector who is continuously present when andwhere the work to be inspected is being performed.

Periodic special inspection. Special inspection by thespecial inspector who is intermittently present where thework to be inspected has been or is being performed.

SPECIAL INSPECTOR. A qualified person employed orretained by an approved agency and approved by the buildingofficial as having the competence necessary to inspect a par-ticular type of construction requiring special inspection.

SPECIAL STRUCTURAL WALL. See Section 1905.1.1.

SPECIFIED. Required by construction documents.

SPECIFIED COMPRESSIVE STRENGTH OFMASONRY, f´m. Minimum compressive strength, expressedas force per unit of net cross-sectional area, required of themasonry used in construction by the construction documents,and upon which the project design is based. Whenever thequantity f´m is under the radical sign, the square root ofnumerical value only is intended and the result has units ofpounds per square inch (psi) (MPa).

SPLICE. The result of a factory and/or field method of join-ing or connecting two or more lengths of a fire-resistant jointsystem into a continuous entity.

SPRAY BOOTH. A mechanically ventilated appliance ofvarying dimensions and construction provided to enclose oraccommodate a spraying operation and to confine and limitthe escape of spray vapor and residue and to exhaust it safely.

SPRAY ROOM. A room designed to accommodate sprayingoperations separated from the remainder of the building by aminimum 1-hour fire barrier.

SPRAYED FIRE-RESISTANT MATERIALS. Cementi-tious or fibrous materials that are sprayed to provide fire-resistant protection of the substrates.

SPRAYING SPACE. An area in which dangerous quantitiesof flammable vapors or combustible residues, dusts or depos-its are present due to the operation of spraying processes. Thebuilding official is authorized to define the limits of thespraying space in any specific case.

STACK BOND. The placement of masonry units in a bondpattern is such that head joints in successive courses are verti-cally aligned. For the purpose of this code, requirements forstack bond shall apply to masonry laid in other than runningbond.

STAGE. A space within a building utilized for entertainmentor presentations, which includes overhead hanging curtains,drops, scenery or stage effects other than lighting and sound.

STAIR. A change in elevation, consisting of one or more ris-ers.

STAIR, SCISSOR. See “Scissor stair.”

STAIRWAY. One or more flights of stairs, either exterior orinterior, with the necessary landings and platforms connect-ing them, to form a continuous and uninterrupted passagefrom one level to another.

STAIRWAY, EXIT ACCESS. See “Exit access stairway.”

STAIRWAY, EXTERIOR. A stairway that is open on atleast one side, except for required structural columns, beams,handrails and guards. The adjoining open areas shall beeither yards, courts or public ways. The other sides of theexterior stairway need not be open.

STAIRWAY, INTERIOR. A stairway not meeting the defi-nition of an exterior stairway.

STAIRWAY, INTERIOR EXIT. See “Interior exit stair-way.”

STAIRWAY, SPIRAL. A stairway having a closed circularform in its plan view with uniform section-shaped treadsattached to and radiating from a minimum-diameter support-ing column.

STANDBY POWER SYSTEM, LEGALLY REQUIRED.An electrical power system that complies with Seattle Elec-trical Code Article 701, Legally Required Standby Systems,and Chapter 27.

[F] STANDPIPE SYSTEM, CLASSES OF. Standpipeclasses are as follows:

Class I system. A system providing 21/2-inch (64 mm)hose connections to supply water for use by fire depart-ments and those trained in handling heavy fire streams.

Class II system. A system providing 11/2-inch (38 mm)hose stations to supply water for use primarily by thebuilding occupants or by the fire department during initialresponse.


DEFINITIONS


Class III system. A system providing 11/2-inch (38 mm)hose stations to supply water for use by building occu-pants and 21/2-inch (64 mm) hose connections to supply alarger volume of water for use by fire departments andthose trained in handling heavy fire streams.

[F] STANDPIPE, TYPES OF. Standpipe types are as fol-lows:

Automatic dry. A dry standpipe system, normally filledwith pressurized air, that is arranged through the use of adevice, such as dry pipe valve, to admit water into the sys-tem piping automatically upon the opening of a hosevalve. The water supply for an automatic dry standpipesystem shall be capable of supplying the system demand.

Automatic wet. A wet standpipe system that has a watersupply that is capable of supplying the system demandautomatically.

Manual dry. A dry standpipe system that does not have apermanent water supply attached to the system. Manualdry standpipe systems require water from a fire depart-ment pumper to be pumped into the system through thefire department connection in order to meet the systemdemand.

Manual wet. A wet standpipe system connected to a watersupply for the purpose of maintaining water within thesystem but does not have a water supply capable of deliv-ering the system demand attached to the system. Manual-wet standpipe systems require water from a fire depart-ment pumper (or the like) to be pumped into the system inorder to meet the system demand.

Semiautomatic dry. A dry standpipe system that isarranged through the use of a device, such as a delugevalve, to admit water into the system piping upon activa-tion of a remote control device located at a hose connec-tion. A remote control activation device shall be providedat each hose connection. The water supply for a semiauto-matic dry standpipe system shall be capable of supplyingthe system demand.

START OF CONSTRUCTION. The date of issuance fornew construction and substantial improvements to existingstructures, provided the actual start of construction, repair,reconstruction, rehabilitation, addition, placement or otherimprovement is within 180 days after the date of issuance.The actual start of construction means the first placement ofpermanent construction of a building (including a manufac-tured home) on a site, such as the pouring of a slab or foot-ings, installation of pilings or construction of columns.

Permanent construction does not include land preparation(such as clearing, excavation, grading or filling), the installa-tion of streets or walkways, excavation for a basement, foot-ings, piers or foundations, the erection of temporary forms orthe installation of accessory buildings such as garages orsheds not occupied as dwelling units or not part of the mainbuilding. For a substantial improvement, the actual “start ofconstruction” means the first alteration of any wall, ceiling,floor or other structural part of a building, whether or not thatalteration affects the external dimensions of the building.

STEEL CONSTRUCTION, COLD-FORMED. That typeof construction made up entirely or in part of steel structuralmembers cold formed to shape from sheet or strip steel suchas roof deck, floor and wall panels, studs, floor joists, roofjoists and other structural elements.

STEEL JOIST. Any steel structural member of a building orstructure made of hot-rolled or cold-formed solid or open-web sections, or riveted or welded bars, strip or sheet steelmembers, or slotted and expanded, or otherwise deformedrolled sections.

STEEL MEMBER, STRUCTURAL. Any steel structuralmember of a building or structure consisting of a rolled steelstructural shape other than cold-formed steel, or steel joistmembers.

STEEP SLOPE. A roof slope greater than two units verticalin 12 units horizontal (17-percent slope).

STONE MASONRY. Masonry composed of field, quarriedor cast stone units bonded by mortar.

Ashlar stone masonry. Stone masonry composed of rect-angular units having sawed, dressed or squared bed sur-faces and bonded by mortar.

Rubble stone masonry. Stone masonry composed ofirregular-shaped units bonded by mortar.

[F] STORAGE, HAZARDOUS MATERIALS. The keep-ing, retention or leaving of hazardous materials in closed con-tainers, tanks, cylinders, or similar vessels; or vesselssupplying operations through closed connections to the ves-sel.

STORM SHELTER. A building, structure or portionsthereof, constructed in accordance with ICC 500 and desig-nated for use during a severe wind storm event, such as a hur-ricane or tornado.

Community storm shelter. A storm shelter not defined asa “Residential Storm Shelter.”

Residential storm shelter. A storm shelter serving occu-pants of dwelling units and having an occupant load notexceeding 16 persons.

STORY. That portion of a building, including basements,located ((included)) between the upper surface of a floor andthe upper surface of the next floor or roof ((next)) above (alsosee “Basement,” “Building height,” “Grade plane” and“Mezzanine”). It is measured as the vertical distance from topto top of two successive tiers of beams or finished floor sur-faces and, for the topmost story, from the top of the floor fin-ish to the top of the ceiling joists or, where there is not aceiling, to the top of the roof rafters.

STORY ABOVE GRADE PLANE. Any story having itsfinished floor surface entirely above grade plane, or in whichthe finished surface of the next floor ((next)) above is:

1. More than 6 feet (1829 mm) above grade plane; or

2. More than 12 feet (3658 mm) above the finishedground level ((at any point)) for more than 25 feet(7620 mm) of the perimeter. Required driveways up to22 feet (6706 mm) wide shall not be considered in cal-culating the 25 foot distance if there is at least 10 feet


DEFINITIONS


(3048 mm) between the driveway and all portions ofthe 25 foot area. See Figure 202S.

STRENGTH (For Chapter 21).

Design strength. Nominal strength multiplied by astrength reduction factor.

Nominal strength. Strength of a member or cross sectioncalculated in accordance with these provisions beforeapplication of any strength-reduction factors.

Required strength. Strength of a member or cross sectionrequired to resist factored loads.

STRENGTH (For Chapter 16).

Nominal strength. The capacity of a structure or memberto resist the effects of loads, as determined by computa-tions using specified material strengths and dimensionsand equations derived from accepted principles of struc-tural mechanics or by field tests or laboratory tests ofscaled models, allowing for modeling effects and differ-ences between laboratory and field conditions.

Required strength. Strength of a member, cross sectionor connection required to resist factored loads or relatedinternal moments and forces in such combinations as stip-ulated by these provisions.

Strength Design. A method of proportioning structuralmembers such that the computed forces produced in themembers by factored loads do not exceed the memberdesign strength [also called “load and resistance factordesign” (LRFD)]. The term “strength design” is used inthe design of concrete and masonry structural elements.

STRUCTURAL COMPOSITE LUMBER. Structuralmember manufactured using wood elements bonded togetherwith exterior adhesives. Examples of structural compositelumber are:

Laminated strand lumber (LSL). A compsite of woodstrand elements with wood fibers primarily oriented alongthe length of the member, where the least dimension of the

wood strand elements is 0.10 inches (2.54 mm) or less andtheir average lengths are a minimum of 150 times the leastdimension of the wood strand elements.

Laminated veneer lumber (LVL). A composite of woodveneer sheet elements with wood fibers primarily orientedalong the length of the member, where the veneer elementthicknesses are 0.25 inches (6.4 mm) or less.

Oriented strand lumber (OSL). A composite of woodstrand elements with wood fibers primarily oriented alongthe length of the member, where the least dimension of thewood strand elements is 0.10 inches (2.54 mm) or less andtheir average lengths are a minimum of 75 times and lessthan 150 times the least dimension of the wood strand ele-ments.

Parallel strand lumber (PSL). A composite of woodstrand elements with wood fibers primarily oriented alongthe length of the member where the least dimension of thewood strand elements is 0.25 inches (6.4 mm) or less andtheir average lengths are a minimum of 300 times the leastdimension of the wood strand elements.

STRUCTURAL ENGINEER IN RESPONSIBLECHARGE. A structural engineer licensed to practice underthe laws of the State of Washington who is engaged by theowner to review and coordinate structural design aspects ofthe project, as determined by the building official, for com-patibility with the design of the building or structure, includ-ing submittal documents prepared by others, deferredsubmittal documents and phased submittal documents.

STRUCTURAL GLUED-LAMINATED TIMBER. Anengineered, stress-rated product of a timber laminating plant,comprised of assemblies of specially selected and preparedwood laminations in which the grain of all laminations isapproximately parallel longitudinally and the laminations arebonded with adhesives.

STRUCTURAL OBSERVATION. The visual observationof the structural system by a registered design professionalfor general conformance to the approved construction docu-ments. Structural observation does not include or waive theresponsibility for the inspection required by Section 108((110)), 1705 or other sections of this code.

STRUCTURALLY QUALIFIED PRODUCTS. Productsthat have been prequalified based on current acceptance andcertification by an accepted authority such as InternationalCode Council (ICC), American Society for Testing and Mate-rials (ASTM), American Concrete Institute (ACI), AmericanInstitute of Steel Construction (AISC), or others widelyaccepted in the engineering field.

[A] STRUCTURE. That which is built or constructed.

SUBDIAPHRAGM. A portion of a larger wood diaphragmdesigned to anchor and transfer local forces to primary dia-phragm struts and the main diaphragm.

SUBSTANTIAL DAMAGE. Damage of any origin sus-tained by a structure whereby the cost of restoring the struc-ture to its before-damaged condition would equal or exceed50 percent of the market value of the structure before thedamage occurred.

FIGURE 202SSTORY ABOVE GRADE PLANE


DEFINITIONS


SUBSTANTIAL IMPROVEMENT. Any repair, recon-struction, rehabilitation, addition or improvement of a build-ing or structure, the cost of which equals or exceeds 50percent of the market value of the structure before theimprovement or repair is started. If the structure has sus-tained substantial damage, any repairs are considered sub-stantial improvement regardless of the actual repair workperformed. The term does not, however, include either:

1. Any project for improvement of a building required tocorrect existing health, sanitary or safety code viola-tions identified by the building official and that are theminimum necessary to assure safe living conditions.

2. Any alteration of a historic structure provided that thealteration will not preclude the structure’s continueddesignation as a historic structure.

((SUBSTANTIAL STRUCTURAL DAMAGE. A condi-tion where:

1. In any story, the vertical elements of the lateral force-resisting system have suffered damage such that the lat-eral load-carrying capacity of the structure in any hori-zontal direction has been reduced by more than 33percent from its predamage condition; or

2. The capacity of any vertical gravity load-carrying com-ponent, or any group of such components, that supportsmore than 30 percent of the total area of the structure’sfloors and roofs has been reduced more than 20 percentfrom its predamage condition and the remaining capac-ity of such affected elements, with respect to all deadand live loads, is less than 75 percent of that requiredby this code for new buildings of similar structure, pur-pose and location.))

SUBSTRUCTURE. The portion of the construction belowand including the deck immediately above the water.

[E] SUNROOM. A one-story structure attached to a buildingwith a glazing area in excess of 40 percent of the gross area ofthe structure’s exterior walls and roof.

SUPERSTRUCTURE. The portion of construction abovethe deck.

Exception: Covered boat moorage.

[F] SUPERVISING STATION. A facility that receives sig-nals and at which personnel are in attendance at all times torespond to these signals.

[F] SUPERVISORY SERVICE. The service required tomonitor performance of guard tours and the operative condi-tion of fixed suppression systems or other systems for theprotection of life and property.

[F] SUPERVISORY SIGNAL. A signal indicating the needof action in connection with the supervision of guard tours,the fire suppression systems or equipment or the maintenancefeatures of related systems.

[F] SUPERVISORY SIGNAL-INITIATING DEVICE.An initiation device, such as a valve supervisory switch,water-level indicator or low-air pressure switch on a dry-pipesprinkler system, whose change of state signals an off-normalcondition and its restoration to normal of a fire protection orlife safety system, or a need for action in connection with

guard tours, fire suppression systems or equipment or mainte-nance features of related systems.

SUSCEPTIBLE BAY. A roof or portion thereof with:

1. A slope less than 1/4-inch per foot (0.0208 rad); or

2. On which water is impounded upon it, in whole or inpart, and the secondary drainage system is functionalbut the primary drainage system is blocked.

A roof surface with a slope of 1/4-inch per foot (0.0208rad) or greater towards points of free drainage is not a suscep-tible bay.

SWIMMING POOL. Any structure intended for swimming,recreational bathing or wading that contains water over 24inches (610 mm) deep. This includes in-ground, above-ground and on-ground pools; hot tubs; spas and fixed-in-place wading pools.

T RATING. The time period that the penetration firestopsystem, including the penetrating item, limits the maximumtemperature rise to 325°F (163°C) above its initial tempera-ture through the penetration on the nonfire side when testedin accordance with ASTM E 814 or UL 1479.

TECHNICAL PRODUCTION AREA. Open elevatedareas or spaces intended for entertainment technicians towalk on and occupy for servicing and operating entertain-ment technology systems and equipment. Galleries, includ-ing fly and lighting galleries, gridirons, catwalks, and similarareas are designed for these purposes.

((TECHNICALLY INFEASIBLE. An alteration of a facil-ity that has little likelihood of being accomplished becausethe existing structural conditions require the removal or alter-ation of a load-bearing member that is an essential part of thestructural frame, or because other existing physical or siteconstraints prohibit modification or addition of elements,spaces or features which are in full and strict compliance withthe minimum requirements for new construction and whichare necessary to provide accessibility.))

TENT. A structure, enclosure or shelter, with or without side-walls or drops, constructed of fabric or pliable material sup-ported in any manner except by air or the contents it protects.

[E] THERMAL ISOLATION. A separation of conditionedspaces, between a sunroom and a dwelling unit, consisting ofexisting or new walls, doors or windows.

THERMOPLASTIC MATERIAL. A plastic material thatis capable of being repeatedly softened by increase of temper-ature and hardened by decrease of temperature.

THERMOSETTING MATERIAL. A plastic material thatis capable of being changed into a substantially nonreform-able product when cured.

THIN-BED MORTAR. Mortar for use in construction ofAAC unit masonry with joints 0.06 inch (1.5 mm) or less.

THROUGH PENETRATION. A breach in both sides of afloor, floor-ceiling or wall assembly to accommodate an itempassing through the breaches.

THROUGH-PENETRATION FIRESTOP SYSTEM. Anassemblage consisting of a fire-resistance-rated floor, floor-ceiling, or wall assembly, one or more penetrating items pass-

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DEFINITIONS


ing through the breaches in both sides of the assembly and thematerials or devices, or both, installed to resist the spread offire through the assembly for a prescribed period of time.

TIE-DOWN (HOLD-DOWN). A device used to resist upliftof the chords of shear walls.

TIE, WALL. Metal connector that connects wythes ofmasonry walls together.

TILE, STRUCTURAL CLAY. A hollow masonry unitcomposed of burned clay, shale, fire clay or mixture thereof,and having parallel cells.

[F] TIRES, BULK STORAGE OF. Storage of tires wherethe area available for storage exceeds 20,000 cubic feet (566m3).

[A] TOWNHOUSE. A single-family dwelling unit con-structed in a group of three or more attached units in whicheach unit extends from the foundation to roof and with openspace on at least two sides.

[F] TOXIC. A chemical falling within any of the followingcategories:

1. A chemical that has a median lethal dose (LD50) ofmore than 50 milligrams per kilogram, but not morethan 500 milligrams per kilogram of body weight whenadministered orally to albino rats weighing between200 and 300 grams each.

2. A chemical that has a median lethal dose (LD50) of morethan 200 milligrams per kilogram, but not more than1,000 milligrams per kilogram of body weight whenadministered by continuous contact for 24 hours (or lessif death occurs within 24 hours) with the bare skin ofalbino rabbits weighing between 2 and 3 kilograms each.

3. A chemical that has a median lethal concentration(LC50) in air of more than 200 parts per million, but notmore than 2,000 parts per million by volume of gas orvapor, or more than 2 milligrams per liter but not morethan 20 milligrams per liter of mist, fume or dust, whenadministered by continuous inhalation for 1 hour (orless if death occurs within 1 hour) to albino rats weigh-ing between 200 and 300 grams each.

TRANSIENT. Occupancy of a dwelling unit or sleeping unitfor not more than 30 days.

TRANSIENT AIRCRAFT. Aircraft based at another locationand that is at the transient location for not more than 90 days.

TRANSIENT LODGING. A building, facility or portionthereof, excluding inpatient medical care facilities and long-term care facilities, that contains one or more dwelling unitsor sleeping units. Examples of transient lodging include, butare not limited to, resorts, group homes, hotels, motels, dor-mitories, homeless shelters, halfway houses and social ser-vice lodging.

TREATED WOOD. Wood and wood-based materials thatuse vacuum-pressure impregnation processes to enhance fireretardant or preservative properties.

Fire-retardant-treated wood. Pressure-treated lumberand plywood that exhibit reduced surface-burning charac-teristics and resist propagation of fire.

Preservative-treated wood. Pressure-treated wood prod-ucts that exhibit reduced susceptibility to damage byfungi, insects or marine borers.

TRIM. Picture molds, chair rails, baseboards, handrails,door and window frames and similar decorative or protectivematerials used in fixed applications.

[F] TROUBLE SIGNAL. A signal initiated by the firealarm system or device indicative of a fault in a monitoredcircuit or component.

TUBULAR DAYLIGHTING DEVICE (TDD). A non-operable fenestration unit primarily designed to transmit day-light from a roof surface to an interior ceiling via a tubularconduit. The basic unit consists of an exterior glazed weather-ing surface, a light-transmitting tube with a reflective interiorsurface, and an interior-sealing device such as a translucentceiling panel. The unit can be factory assembled, or field-assembled from a manufactured kit.

24-HOUR CARE. See “24-hour care” located preceding“AAC masonry.”

TYPE A UNIT. A dwelling unit or sleeping unit designedand constructed for accessibility in accordance with this codeand the provisions for Type A units in ICC A117.1.

TYPE B UNIT. A dwelling unit or sleeping unit designedand constructed for accessibility in accordance with this codeand the provisions for Type B units in ICC A117.1, consistentwith the design and construction requirements of the federalFair Housing Act.

UNDERLAYMENT. One or more layers of felt, sheathingpaper, nonbituminous saturated felt or other approved mate-rial over which a steep-slope roof covering is applied.

UNIT SKYLIGHT. See “Skylight, unit.”

UNSAFE. Structurally unsound, provided with inadequateegress, constituting a fire hazard, or otherwise dangerous tohuman life, or constituting a hazard to safety, health or publicwelfare.

[F] UNSTABLE (REACTIVE) MATERIAL. A material,other than an explosive, which in the pure state or as commer-cially produced, will vigorously polymerize, decompose,condense or become self-reactive and undergo other violentchemical changes, including explosion, when exposed toheat, friction or shock, or in the absence of an inhibitor, or inthe presence of contaminants, or in contact with incompatiblematerials. Unstable (reactive) materials are subdivided as fol-lows:

Class 4. Materials that in themselves are readily capableof detonation or explosive decomposition or explosivereaction at normal temperatures and pressures. This classincludes materials that are sensitive to mechanical orlocalized thermal shock at normal temperatures and pres-sures.

Class 3. Materials that in themselves are capable of deto-nation or of explosive decomposition or explosive reactionbut which require a strong initiating source or which mustbe heated under confinement before initiation. This classincludes materials that are sensitive to thermal or mechan-ical shock at elevated temperatures and pressures.

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DEFINITIONS


Class 2. Materials that in themselves are normally unsta-ble and readily undergo violent chemical change but donot detonate. This class includes materials that canundergo chemical change with rapid release of energy atnormal temperatures and pressures, and that can undergoviolent chemical change at elevated temperatures andpressures.

Class 1. Materials that in themselves are normally stablebut which can become unstable at elevated temperaturesand pressure.

[F] USE (MATERIAL). Placing a material into action,including solids, liquids and gases.

UTILITY TRANSFORMER VAULT. Vaults containingtransformer equipment owned by Seattle City Light or otherelectric power utility.

VAPOR PERMEABLE. The property of having a moisturevapor permeance rating of 5 perms (2.9 × 10-10 kg/Pa × s ×m2) or greater, when tested in accordance with the desiccantmethod using Procedure A of ASTM E 96. A vapor perme-able material permits the passage of moisture vapor.

VAPOR RETARDER CLASS. A measure of a material orassembly’s ability to limit the amount of moisture that passesthrough that material or assembly. Vapor retarder class shallbe defined using the desiccant method of ASTM E 96 as fol-lows:

Class I: 0.1 perm or less.

Class II: 0.1 < perm ≤ 1.0 perm.

Class III: 1.0 < perm ≤ 10 perm.

VEHICLE BARRIER. A component or a system of compo-nents, near open sides or walls of garage floors or ramps, thatacts as a restraint for vehicles.

VEHICULAR GATE. A gate that is intended for use at avehicular entrance or exit to a facility, building or portionthereof, and that is not intended for use by pedestrian traffic.

VENEER. A facing attached to a wall for the purpose of pro-viding ornamentation, protection or insulation, but notcounted as adding strength to the wall.

[M] VENTILATION. The natural or mechanical process ofsupplying conditioned or unconditioned air to, or removingsuch air from, any space.

VINYL SIDING. A shaped material, made principally fromrigid polyvinyl chloride (PVC), that is used as an exteriorwall covering.

[F] VISIBLE ALARM NOTIFICATION APPLIANCE. Anotification appliance that alerts by the sense of sight.

WALKWAY, PEDESTRIAN. A walkway used exclusivelyas a pedestrian trafficway.

WALL. A vertical element with a horizontal length-to-thick-ness ratio greater than three, used to enclose space.

Cavity wall. A wall built of masonry units or of concrete,or a combination of these materials, arranged to provide anairspace within the wall, and in which the inner and outerparts of the wall are tied together with metal ties.

Composite wall. A wall built of a combination of two ormore masonry units bonded together, one forming thebackup and the other forming the facing elements.

Dry-stacked, surface-bonded wall. A wall built of con-crete masonry units where the units are stacked dry, with-out mortar on the bed or head joints, and where both sidesof the wall are coated with a surface-bonding mortar.

Masonry-bonded hollow wall. A multi-wythe wall builtof masonry units arranged to provide an air space betweenthe wythes and with the wythes bonded together withmasonry units.

Parapet wall. The part of any wall entirely above the roofline.

WALL, LOAD-BEARING. Any wall meeting either of thefollowing classifications:

1. Any metal or wood stud wall that supports more than100 pounds per linear foot (1459 N/m) of vertical loadin addition to its own weight.

2. Any masonry or concrete wall that supports more than200 pounds per linear foot (2919 N/m) of vertical loadin addition to its own weight.

WALL, NONLOAD-BEARING. Any wall that is not aload-bearing wall.

((WALL PIER. See Section 1905.1.1.))

[F] WATER-REACTIVE MATERIAL. A material thatexplodes; violently reacts; produces flammable, toxic or otherhazardous gases; or evolves enough heat to cause autoigni-tion or ignition of combustibles upon exposure to water ormoisture. Water-reactive materials are subdivided as follows:

Class 3. Materials that react explosively with water with-out requiring heat or confinement.

Class 2. Materials that react violently with water or havethe ability to boil water. Materials that produce flammable,toxic or other hazardous gases or evolve enough heat tocause autoignition or ignition of combustibles upon expo-sure to water or moisture.

Class 1. Materials that react with water with some releaseof energy, but not violently.

WATER-RESISTIVE BARRIER. A material behind anexterior wall covering that is intended to resist liquid waterthat has penetrated behind the exterior covering from furtherintruding into the exterior wall assembly.

WEATHER-EXPOSED SURFACES. Surfaces of walls,ceilings, floors, roofs, soffits and similar surfaces exposed tothe weather except the following:

1. Ceilings and roof soffits enclosed by walls, fascia,bulkheads or beams that extend a minimum of 12inches (305 mm) below such ceiling or roof soffits.

Interpretation I202U: USE, where otherwise mentionedin this code, is equivalent to character of occupancy and notintended to be construed as the definition of “use” in theLand Use Code.


DEFINITIONS


2. Walls or portions of walls beneath an unenclosed roofarea, where located a horizontal distance from an openexterior opening equal to at least twice the height of theopening.

3. Ceiling and roof soffits located a minimum horizontaldistance of 10 feet (3048 mm) from the outer edges ofthe ceiling or roof soffits.

[F] WET-CHEMICAL EXTINGUISHING SYSTEM. Asolution of water and potassium-carbonate-based chemical,potassium-acetate-based chemical or a combination thereof,forming an extinguishing agent.

WHARF. A structure or bulkhead constructed of wood,stone, concrete or similar material built at the shore of a har-bor, lake or river for vessels to lie alongside of, and to anchorpiers or floats.

WHEELCHAIR SPACE. A space for a single wheelchairand its occupant.

WIND-BORNE DEBRIS REGION. Areas within hurri-cane-prone regions located:

1. Within 1 mile (1.61 km) of the coastal mean high waterline where the ultimate design wind speed, Vult, is 130mph (58 m/s) or greater; or

2. In areas where the ultimate design wind speed is 140mph (63.6 m/s) or greater.

For Risk Category II buildings and structures and RiskCategory III buildings and structures, except health carefacilities, the windborne debris region shall be based on Fig-ure 1609A. For Risk Category IV buildings and structuresand Risk Category III health care facilities, the windbornedebris region shall be based on Figure 1609B.

WINDFORCE-RESISTING SYSTEM, MAIN. See“Main Windforce-Resisting System.”

WIND SPEED, Vult. Ultimate design wind speeds.

WIND SPEED, Vasd. Nominal design wind speeds.

WINDER. A tread with nonparallel edges.

WIRE BACKING. Horizontal strands of tautened wireattached to surfaces of vertical supports which, when coveredwith the building paper, provide a backing for cement plaster

[F] WIRELESS PROTECTION SYSTEM. A system or apart of a system that can transmit and receive signals withoutthe aid of wire.

WOOD SHEAR PANEL. A wood floor, roof or wall com-ponent sheathed to act as a shear wall or diaphragm.

WOOD STRUCTURAL PANEL. A panel manufacturedfrom veneers, wood strands or wafers or a combination ofveneer and wood strands or wafers bonded together withwaterproof synthetic resins or other suitable bonding sys-tems. Examples of wood structural panels are:

Composite panels. A wood structural panel that is com-prised of wood veneer and reconstituted wood-basedmaterial and bonded together with waterproof adhesive;

Oriented strand board (OSB). A mat-formed woodstructural panel comprised of thin rectangular woodstrands arranged in cross-aligned layers with surface lay-ers normally arranged in the long panel direction andbonded with waterproof adhesive; or

Plywood. A wood structural panel comprised of plies ofwood veneer arranged in cross-aligned layers. The pliesare bonded with waterproof adhesive that cures on appli-cation of heat and pressure.

[F] WORKSTATION. A defined space or an independentprincipal piece of equipment using HPM within a fabricationarea where a specific function, laboratory procedure orresearch activity occurs. Approved or listed hazardous mate-rials storage cabinets, flammable liquid storage cabinets orgas cabinets serving a workstation are included as part of theworkstation. A workstation is allowed to contain ventilationequipment, fire protection devices, detection devices, electri-cal devices and other processing and scientific equipment.

WYTHE. Each continuous, vertical section of a wall, onemasonry unit in thickness.

YARD. An open space, other than a court, unobstructed fromthe ground to the sky, except where specifically provided bythis code, on the lot on which a building is situated.

[F] ZONE. A defined area within the protected premises. Azone can define an area from which a signal can be received,an area to which a signal can be sent or an area in which aform of control can be executed.

[F] ZONE, NOTIFICATION. An area within a building orfacility covered by notification appliances which are acti-vated simultaneously.

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Documents

Seattle DPD - 2012 Seattle Building Code, Chapter 2 Definitions