FVCC Fire Rescue Building Construction. OBJECTIVES 2-9.1 Identify the basic structural characteristics of the following types of building construction:

FVCC Fire Rescue

Building Construction

OBJECTIVES

•2-9.1 Identify the basic structural characteristics of the following types of building construction: (3-3.11)

2-9.1.1 Fire resistive (Type I) 2-9.1.2 Noncombustible (Type II) 2-9.1.3 Ordinary (Type III) 2-9.1.4 Heavy timber (Type IV) 2-9.1.5 Wood frame (Type V)

OBJECTIVES•2-9.2 Identify the two basic types of light

wood framing.▫2-9.1 Balloon framing▫2-9.2 Platform framing

•2-9.3 Identify the main components of lightweight framing construction.▫2-9.3.1 Footing▫2-9.3.2 Foundation

OBJECTIVES▫2-9.3.3 Plate▫2-9.3.4 Stud▫2-9.3.5 Joist▫2-9.3.6 Rafter▫2-9.3.7 Sill▫2-9.3.8 Header▫2-9.3.9 Ridge Board▫2-9.3.10 Eave

OBJECTIVES▫2-9.3.11 Fascia▫2-9.3.12 Soffit▫2-9.3.13 Interior finish

2-9.3.13.1 Plaster 2-9.3.13.2 Drywall

▫2-9.3.14 Exterior finish 2-9.3.14.1 Brick veneer 2-9.3.14.2 Sheathing

OBJECTIVES

•2-9.4Identify the three, broadly classified, categories of roofs from a firefighting standpoint.▫2-9.4.1 Flat roofs▫2-9.4.2 Pitched roofs▫2-9.4.3 Curved roofs

OBJECTIVES

•2-9.5Identify structural components of large structural systems.▫2-9.5.1 Beams▫2-9.5.2 Columns▫2-9.5.3 Arches▫2-9.5.4 Cables▫2-9.5.5 Trusses

OBJECTIVES•2-9.6Identify the components of truss

construction.▫2-9.6.1 Chords▫2-9.6.2 Web or diagonal members▫2-9.6.3 Gusset plate

•2-9.7Identify three hazards associated with truss and lightweight construction. (3-3.11)

OBJECTIVES

•2-9.7 Identify dangerous building conditions created by fire and fire suppression activities. (3-3.9, 3-3.11)

•2-9.8 Identify the term “building collapse”. (3-3.9, 3-3.11)

•2-9.9 Identify five indicators of building collapse. (3-3.9, 3-3.11)

OBJECTIVES•2-9.11 Identify the effects of fire and fire

suppression activities on the following building materials. (3-3.9, 3-3.11)

2-9.11.1 Wood 2-9.11.2 Masonry 2-9.11.3 Cast iron 2-9.11.4 Steel 2-9.11.5 Reinforced concrete 2-9.11.6 Gypsum wallboard 2-9.11.7 Glass 2-9.11.8 Plaster on lath

OBJECTIVES

•2-9.11 Identify the following terms as they relate to building construction: (3-3.11)▫2-9.12.1 Load bearing wall▫2-9.12.2 Non-load-bearing wall▫2-9.12.3 Party wall▫2-9.12.4 Fire wall▫2-9.12.5 Partition wall ▫2-9.12.6 Cantilever or unsupported wall▫2-9.12.7 Parapet wall

OBJECTIVES•2-9.13 Identify the effects of the

following items in a burning building: (3-3.9, 3-3.11)

2-9.13.1 Intense heat 2-9.13.2 Dense smoke 2-9.13.3 Large volume of water pour

onto and into structure▫IFSTA, Essentials, 4th ed, Chapter 3▫Delmar, Firefighter Handbook, 2000, Chapter

13

BASIC STRUCTURAL CHARACTERISTICS

•Fire Resistive (Type I)▫Structural members are noncombustible or

limited combustible materials.▫Primary hazard contents.▫Ability to confine fire compromised by

openings.

Precast Concrete Bldgs PC2Precast Concrete Bldgs PC2

3s

A beam being placed on columns. The beams are notched to accept the double Ts.

A double T being lowered into place on the beams

The double Ts are notched to fit onto the beams and are held in place by their weight.

Flammable liquids from ruptured fuel tanks can travel to lower levels through penetrations in the deck.

A parking deck attached to an office building.

Parking decks can be found on top of or below occupied spaces. In this building, the first several floors of the structure are parking deck topped with offices.

A stand-alone parking deck.

Stairways in parking decks are often open. Expect heavy smoke conditions.

HAZARDS OF PRECAST CONCRETE : Slabs are transported to the site and then lifted into position with a crane. During the construction process, floors are temporarily connected to the columns. Particular attention must be given to ensure that the concrete has properly cured before being placed into position and loaded. Loads need to be constantly monitored during the construction process to prevent overstressing components. Local failure could trigger a progressive (pancake type) collapse of all or large parts of the structure.

HAZARDS OF POST-TENSIONING : The weight of the concrete is transferred to the columns after tensioning. This situation presents a potential for catastrophic collapse if a column fails. The tendons and anchors used for post-tensioning are left exposed. They may become heat collectors in a fire. Therefore, it is highly recommended that anchors be fireproofed immediately after tensioning.

CUTTING THROUGH TENSIONED CONCRETE: Cables embedded in the concrete are under tension. Cutting a tensioned cable can cause severe injury to the firefighters as the tension is relieved and damage the concrete with a loss of load-bearing capability. Cutting tensioned cables can lead to a collapse of the structure. Therefore, do not cut through a concrete parking deck structure. Construction workers often X-ray the floor before cutting to locate the tensioned cables.

PARKING DECK COLLAPSE • If the concrete parking deck structure has been rattled, such as in an explosion or

other major impact, it is possible that components may have shifted and may be prone to collapse. Always evaluate the need to enter parking decks in these situations. Parking decks may also be in danger of collapse because of improperly cured concrete or overloading caused by vehicle or ice/snow/rain water accumulations. Personnel should also be observant for concrete that has been removed from columns, beams, or the decks themselves, exposing the reinforcing steel. Concrete may have been removed over time, before the fire, as a result of having been struck by vehicles. Exposed steel will begin to lose its strength when the temperature reaches 1,0007F and may be in danger of collapse, depending on the load carried. As mentioned previously, do not cut through the concrete structures because of the likelihood of compromising steel reinforcement and possibly causing injury or collapse.

• Parking decks are becoming more and more common. Preplan these types of structures in your jurisdiction, and develop the appropriate operating plans and guidelines.

First interstate Bank Building (Los Angles ) Fire resistive type I construction ( believe it or not!)Photo by: New York Board of Underwriters

CONCRETE BEHAVIOR IN FIRE

Under fire conditions, concrete resists compressive stresses and yet protects the tensile Under fire conditions, concrete resists compressive stresses and yet protects the tensile strength of the encased steel. Spalling, the failure of the concrete because of entrapped strength of the encased steel. Spalling, the failure of the concrete because of entrapped water's rapid expansion as it turns to steam, may expose the steel reinforcement. Once water's rapid expansion as it turns to steam, may expose the steel reinforcement. Once the unprotected steel is exposed to fire conditions, collapse may occur rapidly as the the unprotected steel is exposed to fire conditions, collapse may occur rapidly as the steel loses its ability to carry the load. Concrete absorbs a great amount of heat. In the steel loses its ability to carry the load. Concrete absorbs a great amount of heat. In the short term this is not a problem, but long-term heat exposure complicates firefighting short term this is not a problem, but long-term heat exposure complicates firefighting efforts. efforts.


•Noncombustible (Type II)▫Similar to fire resistive (Type I); only degree of

fire resistance is less.▫In some cases, materials with no fire resistance

may be used.▫Primary hazard contents▫Heat buildup, during a fire, may cause

structural supports to fail.▫Type of roof material may contribute to fire

extension.


•Ordinary (Type III)▫Exterior walls and structural members are

noncombustible or limited combustible materials.

▫Interior structural members completely or partially of wood.

▫Wood used has smaller dimensions than Type IV.

▫Primary hazard is fire and smoke spread through concealed spaces.

A view of ordinary construction from the street.

The same building. You can see the header courses of brick by looking down the side. Always look at as many sides of the building as possible to determine construction, occupancy, and floor.


Ordinary type III ConstructionPhoto by: Warren Fuchs Brooklyn Dispatcher


•Heavy timber (Type IV) ▫ Exterior and interior walls and associated structural

members are noncombustible or limited combustible materials.

▫ Other interior structural members are made of solid or laminated wood with no concealed spaces.

▫ Wood has large enough dimensions to be considered heavy timber.

▫ Primary hazard: the combustible contents of the structural members.

▫ Because of the amount of heat given off by the structural members, the building may pose serious exposure protection problems.


•Wood frame (Type V) ▫All walls and structural supports are made

completely or partially of wood of dimensions less than heavy timber.

▫Presents unlimited potential for fire spread.▫May present a serious exposure problem

especially if exposures are of similar construction.

The Outer Shell

LIGHT WOOD FRAMING•Balloon framing

▫ Construction can have open channels from the foundation to the attic.

▫ Framing is usually covered with an interior finish of plaster or drywall.

▫ This balloon-frame structure can easily be recognized by the roofline façade. Because of the fire escapes on the “B” side , anticipate that there are front and rear apartments on each floor where there should be only one large unit. The floor plan will also be different from what you would normally find.

The building industry calls these cross braces firestopping. In fact, their purpose is to brace the stud (which is a column receiving compressive loads) at about midpoint, thus greatly increasing its load-carrying capacity. Their firestopping value is incidental-firestopping should cut off the wall voids from the floor voids.

Wait until we get to void spaces

LIGHT WOOD FRAMING

•Platform framing▫Construction has each floor constructed on

its own platform, reducing open channels in the wall.

▫Framing is usually covered with an interior finish of plaster or drywall.

LIGHTWEIGHT FRAMING CONSTRUCTION

•Footing: That part of the building that rests on the bearing soil and is wider than the foundation wall. Also the base for a column. It spreads the weight of a wall or column and presents settling.

•Foundation: The supporting part of a wall usually of masonry or concrete and at least partially underground.

Foundation Footings

Stepped footing can support a concrete block wall. Blocks have nominal dimensions of 8 by 8 by 16 inches (the actual dimensions are actually 3/8 inch smaller than these to allow for mortar joints). They are hollow when laid-up; steel reinforcing bar called rebar is added and the hollows in the blocks are often filled with concrete. They lend themselves to construction where forming concrete is difficult or impractical. Concrete blocks are also used for standard foundation wall construction. Here they are supported by a concrete footing; both are reinforced with steel rods and the concrete blocks are filled with grout.A concrete pier, resting on a footing, may be used to help support beams at mid-span. Though some older homes rest entirely on piers, this method has been phased out in favor of stronger foundations.


•Plate: The top or bottom horizontal structural member of a frame wall or partition.

•Stud: Vertical structural uprights which make up the walls and partitions in a frame building.

•Joist: A framing member which directly supports the floor.

(9) This is a "flitch plate girder," a piece of steel plate sandwiched between two wood beams. It tells (9) This is a "flitch plate girder," a piece of steel plate sandwiched between two wood beams. It tells us that the beam is carrying an unusually heavy load or long span. If the wood burns, the steel will us that the beam is carrying an unusually heavy load or long span. If the wood burns, the steel will buckle and the beam will fail. Note this hazard on the preplan.buckle and the beam will fail. Note this hazard on the preplan.


•Sill: The bottom rough structural member that rests on the foundation or the bottom exterior member of a window or door or other masonry below.

•Head: The top of a window or doorframe.


•Ridge Board: The horizontal timber or beam at the ridge of a roof, to which the upper ends of the rafters are attached. (Next Slide)

•Eave: The lower edge of a roof, usually projecting beyond the sides of a building.

•Rafter: A beam that supports a roof. (next slide)


•Cornice: A horizontal projection that crowns or finishes the eave of a building.

•Fascia: A flat vertical board located at the outer face of a cornice.

•Soffit: A lower horizontal surface such as the undersurface of eaves or cornice.

Fascia and Soffit Fascia and Soffit


•Interior finish▫Plaster: A fire-resistive cement material

that is applied over lathing, which is either a wire mesh or a gypsum board with a fibrous paper.

▫Drywall: A system of interior wall finish using sheets of gypsum board and taped joints.


•Exterior finish▫Brick veneer: Single thickness of brick

wall facing placed over frame construction or masonry other than brick.

▫Sheathing: Covering applied to the framing of a building to which siding is applied.

Brick veneerBrick veneer

The brick wall is connected to the wooden wall by thin steel tabs nailed to the wall.

This makes brick masonry and veneer brick walls look alike. Know your buildings. This makes brick masonry and veneer brick walls look alike. Know your buildings. Recently, a Dallas, Texas, firefighter was killed in the collapse of a brick wall of a Recently, a Dallas, Texas, firefighter was killed in the collapse of a brick wall of a building that was being renovated. When in doubt, consider the wall to be brick veneer. building that was being renovated. When in doubt, consider the wall to be brick veneer.

Click here to enlarge image

Notice the brick veneer on the front of this platform-frame, single-family house. On the Notice the brick veneer on the front of this platform-frame, single-family house. On the left side of the first floor, firefighters can expect to find a vaulted ceiling and must be left side of the first floor, firefighters can expect to find a vaulted ceiling and must be cautious to ensure that the fire is not rolling over their heads. As they move deeper into cautious to ensure that the fire is not rolling over their heads. As they move deeper into the building, they should check it with a pike pole or a quick shot of water.the building, they should check it with a pike pole or a quick shot of water.

This new lightweight frame construction is located in the rehab zone. The front is brick This new lightweight frame construction is located in the rehab zone. The front is brick veneer; the sides are vinyl. It most likely was built with truss floor and roof supports. veneer; the sides are vinyl. It most likely was built with truss floor and roof supports. Check it at the door before moving in too far.Check it at the door before moving in too far.

ROOFS• Flat roofs• Pitched roofs

▫ Gable roofs▫ Hip roofs▫ Gambrel roofs▫ Mansard roofs▫ Shed roofs▫ Butterfly roofs▫ Monitor roofs▫ Saw tooth roofs

• Curved roofs

LARGE STRUCTURAL SYSTEMS• Beams: A structural member subjected to

loads perpendicular to its length.• Columns: A vertical supporting member.• Arches: Curved structural member in which

the interior stresses are primarily compressive. Arches develop inclined reactions at their support.

• Cables: Flexible structural members in which the stresses in the cable are tension stresses.

• Trusses: Framed structural units made of a group of triangles in one plane.

TRUSS CONSTRUCTION

•Chords: Top and bottom horizontal members of a truss.

•Web or diagonal members: Vertical members between the chords.

•Gusset plate: Plate that is used to connect the members of a wood or metal truss.

Photo R275 - The bottom chord of this truss is under a tensile (pulling) load when in Photo R275 - The bottom chord of this truss is under a tensile (pulling) load when in place. place. It consists of three pieces of wood with four gusset plate connectors. When the gusset It consists of three pieces of wood with four gusset plate connectors. When the gusset plate heats up, the heat is transferred to the teeth by conduction. The heated teeth plate heats up, the heat is transferred to the teeth by conduction. The heated teeth destroy the wood fibers in tension which were gripping the teeth. It is called pyrolytic destroy the wood fibers in tension which were gripping the teeth. It is called pyrolytic decomposition, burning without flame as occurs when you burn the company number decomposition, burning without flame as occurs when you burn the company number into an axe handle. into an axe handle.

Photo R244Photo R244 - This construction illustrates the value of - This construction illustrates the value of trusses. To build a conventional building this wide would trusses. To build a conventional building this wide would have required heavy roof beams or bothersome interior have required heavy roof beams or bothersome interior columns.The walls would need to be much heavier to columns.The walls would need to be much heavier to carry the weight of the long rafters.The truss provides carry the weight of the long rafters.The truss provides

clear spans at low cost. Know your buildings and use the clear spans at low cost. Know your buildings and use the thermal imager (Firefighter’s Radar) to detect hidden thermal imager (Firefighter’s Radar) to detect hidden

fire. fire.

HAZARDS ASSOCIATED WITH TRUSS & LIGHTWEIGHT CONSTRUCTION

•Designed to support only own weight•If one fails, a domino effect usually occurs

until total collapse has resulted.•Rapid failure under fire conditions:

▫Usually 5 to 10 minutes▫Wood – ¼ inch char▫Steel 1000 degree F.

(5) In some cases, an unprotected steel beam or a flitch plate girder (see photo 9) is used to (5) In some cases, an unprotected steel beam or a flitch plate girder (see photo 9) is used to provide a wide, clear span. The failure of a steel beam cost the life of a Georgia firefighter. provide a wide, clear span. The failure of a steel beam cost the life of a Georgia firefighter.

(6) The peaked roof is supported on lightweight wood trusses. Personnel operating from a tower (6) The peaked roof is supported on lightweight wood trusses. Personnel operating from a tower ladder should perform ventilation. No code requires that the roof be a safe operating platform for ladder should perform ventilation. No code requires that the roof be a safe operating platform for firefightersfirefighters

DANGEROUS CONDITIONS CREATED BY FIRE & FIRE SUPRESSION

•Two primary types of dangerous conditions.

Conditions that contribute to the spread and intensity of the fire.

Conditions that make the building susceptible to collapse.


•Conditions that contribute to the spread and intensity of the fire.▫Fire loading

Presence of large amounts of combustible materials in an area of a building.

Arrangement of combustible materials in a building.

▫Combustible furnishings and finishes▫Roof coverings▫Wooden floors and ceilings

Patrons attempted to leave by the hallway to the club's front door, but the exit there soon grew choked. Most of the crowd apparently attempted to leave through that exit, fire officials said.

The rush to exit the front left a pile of people, trapped in the burning building. Fire officials estimated the number of people inside as less than 300, the club's official capacity.

Rescuers attempted to pull people from the front door pile. According to authorities, most of the bodies later found were near the front door.

Within minutes, the building was in flames. Firefighters fought the blaze in vain but were able to rescue some people inside.


▫Large open spaces▫Building collapse▫Lightweight and truss construction▫Construction, renovation and demolition

• A trained eye would detect that this A trained eye would detect that this Suburban Hospital Bethesda MD Outpatient Suburban Hospital Bethesda MD Outpatient Center is a post tensioned concrete Center is a post tensioned concrete construction job and all that dry hard construction job and all that dry hard concrete is not attached to the building and concrete is not attached to the building and is supported only by the fire vulnerable is supported only by the fire vulnerable wooden falsework Smoke might obscure wooden falsework Smoke might obscure vision so the only sound precaution is for the vision so the only sound precaution is for the FD to be aware on a daily basis of this deadly FD to be aware on a daily basis of this deadly type of construction.type of construction.

Note the wood stud bearing wall against the concrete block firewall. The code Note the wood stud bearing wall against the concrete block firewall. The code applicable to this building permits no penetration of the firewall. Other codes applicable to this building permits no penetration of the firewall. Other codes permit the firewall to be used structurally, thus providing fire penetrations. Know permit the firewall to be used structurally, thus providing fire penetrations. Know your buildings! (BCFS3, 234) your buildings! (BCFS3, 234)

Void Spaces

Heavy wood firestopping was removed to install a standpipe main requested by the fire department. The Fire Department of New York, which developed standpipe operations, finds it is faster to stretch directly to the third floor instead of using the standpipe Here, the firestopping was not replaced because the gypsum board ceiling was installed right after I took this picture. A void fire would spread throughout the voids, following the fire main.

Fire would spread from floor to floor through the piping holes. The collapse hazard may drive firefighters from the building, especially if the floors are of truss construction. You did not lose the building—the construction techniques used, which made it deadly for firefighters to remain in the building, destroyed it. It is a combustible building, a type that can be destroyed easily by fire.

4) Wooden I-beams are no better than trusses as fire stops because they legally can have holes for wiring and large holes for ducts, metal, or plastic.

For economy, apartment kitchens are built back-to-back. If the connection is not For economy, apartment kitchens are built back-to-back. If the connection is not adequately firestopped (practically impossible), expect early extension of a kitchen fire to adequately firestopped (practically impossible), expect early extension of a kitchen fire to the next unit. the next unit.

A fire in one kitchen will be in the next kitchen by the time you arrive. Chapter 5 of A fire in one kitchen will be in the next kitchen by the time you arrive. Chapter 5 of BCFS3 contains a full discussion of the deficiencies in fire containment in garden BCFS3 contains a full discussion of the deficiencies in fire containment in garden apartments and similar commercial structures. apartments and similar commercial structures.

This flat roof attic space, or cockloft, goes from side to side and from the front to the This flat roof attic space, or cockloft, goes from side to side and from the front to the back of this building. When the fire reaches the cockloft space, it will spread horizontally back of this building. When the fire reaches the cockloft space, it will spread horizontally along the direction of the roof joistsalong the direction of the roof joists

This lightweight truss loft will allow fire to spread horizontally similar to the This lightweight truss loft will allow fire to spread horizontally similar to the way it would in a cockloft; however, a cockloft is built with 2-inch 2 12-inch way it would in a cockloft; however, a cockloft is built with 2-inch 2 12-inch wood, whereas this fire will spread along and through the trusses. wood, whereas this fire will spread along and through the trusses. Because of the fire spread and the members' low mass, the members will Because of the fire spread and the members' low mass, the members will fail within five to 10 minutes.fail within five to 10 minutes.

Roof Coverings

BUILDING COLLAPSE•Resulting from damage to the structural

system of the building caused by the fire or by firefighting operations.

•Most likely time when firefighters are killed or injured.

•Most likely time when R.I.T. is put into action.

•When Building Collapse is evident or possible, operations should be made from the corners of the buildings!!

April 2004 - April 2004 - Ebenezer Ebenezer Baptist Baptist Church - Church - Pittsburgh, Pittsburgh, PA PA

Collapse Zone•1 ½ times the

height of the building.

INDICATORS OF BUILDING COLLAPSE

•Cracks or separations in walls, floors, ceilings and roof structures.

•Evidence of existing structural instability such as the presence of tie rods.

•Stairs that hold the wall together•Loose bricks, blocks or stones falling from

the building•Deteriorated mortar between the

masonry.•Walls that appear to be leaning in one

direction or another

Collapsing floor joists can pull down a masonry wall. The so-called fire cut (cutting the Collapsing floor joists can pull down a masonry wall. The so-called fire cut (cutting the end of the joist off at an angle) was developed to prevent any leverage on the wall. end of the joist off at an angle) was developed to prevent any leverage on the wall. (BCFS3, 166)(BCFS3, 166)


•Are there any of these signs on buildings in your town?

•Bet you there are!


•Structural members that appear to be distorted or pulling away from the walls

•Fires beneath floors that support heavy machinery or other extreme weight loads.

•Prolonged fire exposure to the structural members.

•Unusual creaks and cracking noises.

EFFECTS OF FIRE & FIRE SUPPRESSION

•Wood – reaction depends on size of the wood component. (The smaller the size, the more likely to lose integrity Type IV Construction v. Type V Construction)▫Moisture content of wood (old v. new)▫Application of water has no adverse impact

on

(11) Lightweight floor construction will not withstand more than a few minutes of fire (11) Lightweight floor construction will not withstand more than a few minutes of fire exposure and cannot support a company advancing through the front door. A basement fire exposure and cannot support a company advancing through the front door. A basement fire may have to be attacked from a window or an outside entrance. (Photo by Lazaro Acosta.) may have to be attacked from a window or an outside entrance. (Photo by Lazaro Acosta.)

This beam is made up of planks glued This beam is made up of planks glued together. The industry calls this together. The industry calls this "engineered wood"; all wood products "engineered wood"; all wood products that are not simply sawn from a log that are not simply sawn from a log could be called "engineered wood." could be called "engineered wood." The industry brags that this wood only The industry brags that this wood only chars un-der fire conditions that would chars un-der fire conditions that would cause a steel beam to fail; it neglects cause a steel beam to fail; it neglects to mention that many, possibly most, to mention that many, possibly most, of the beams are supported on of the beams are supported on unprotected steel columns and are unprotected steel columns and are often connected with steel ties. often connected with steel ties.

Laminated beams can be formed in shapes such as these curves. A fire Laminated beams can be formed in shapes such as these curves. A fire spreading across this polished ceiling is best fought by smooth-bore streams spreading across this polished ceiling is best fought by smooth-bore streams that can reach the ceiling and, so to speak, "fireproof" the wood. that can reach the ceiling and, so to speak, "fireproof" the wood.

Commonly found in churches, these laminated Commonly found in churches, these laminated timbers are formed into arches or rigid frames. timbers are formed into arches or rigid frames. Such arches are most often tied together foot to Such arches are most often tied together foot to foot with steel rods. If the church is built on a foot with steel rods. If the church is built on a slab, the rods are buried in the slab. If there is a slab, the rods are buried in the slab. If there is a basement, the rods may be ex-posed to a basement, the rods may be ex-posed to a basement fire, causing them to weaken or basement fire, causing them to weaken or come loose, and the arches are likely to come loose, and the arches are likely to collapse. (BCFS3, 74-78) collapse. (BCFS3, 74-78)

Plywood delaminates. The layers Plywood delaminates. The layers come apart, thus the burning surface come apart, thus the burning surface area and the intensity of the fire are area and the intensity of the fire are increased. (BCFS3, 114) increased. (BCFS3, 114)

This is oriented strand board (OSB), This is oriented strand board (OSB), chips of wood glued together. If chips of wood glued together. If someone were to burn comparable someone were to burn comparable strips of OSB and conventional strips of OSB and conventional plywood to determine if there is a plywood to determine if there is a significant difference in burning significant difference in burning characteristics, I would be happy to characteristics, I would be happy to hear of the results. hear of the results.

This is chipboard, which has been used for flooring in some trailers. A St. Mary's This is chipboard, which has been used for flooring in some trailers. A St. Mary's County, Maryland, firefighter went through the floor as the water-soaked chipboard County, Maryland, firefighter went through the floor as the water-soaked chipboard collapsed. This loaded sample collapsed in a couple of minutescollapsed. This loaded sample collapsed in a couple of minutes


•Masonry▫Minimally affected by fire (heat).▫Mortar between masonry components subject

to more deterioration and weakening from fire.▫Rapid cooling may cause some masonry

components such as bricks, blocks or stone to spall.

▫Masonry components should be inspected after extinguishment to determine signs of damage.


•Cast Iron▫Found only in older buildings.▫Bolts and other fastening devices may fail

when exposed to fire, permitting large sections of cast iron walls to fall.

•Steel▫Members elongate when heated (50 ft beam

may elongate 4 inches when heated to 1000 degrees F.

▫If ends are restrained, it will buckle or fail somewhere in the middle.

▫Failure can be anticipated at 1000 degrees F.

These gas lines in a garden apartment basement are poorly attached to the structure. A These gas lines in a garden apartment basement are poorly attached to the structure. A fire caused the line supports to fail. Fortunately, the firefighters were on the escape side fire caused the line supports to fail. Fortunately, the firefighters were on the escape side of the pipes, which dropped to the floor and ruptured, releasing gas to intensify the fire. of the pipes, which dropped to the floor and ruptured, releasing gas to intensify the fire. (BCFS3, 222-223) (BCFS3, 222-223)


•Reinforced concrete▫Loses strength and spalls.▫Heat may cause failure of bond between

concrete and steel reinforcement.•Gypsum wallboard

▫Excellent heat-resistant and fire-retardant properties.

▫Will gradually break down under fire conditions.

▫Members protected by gypsum could be exposed to high temperatures if gypsum fails.


•Glass/fiberglass▫Glass does not contribute to the fire load,

but resins used in fiberglass will.▫Heated glass may crack when hit by a fire

stream.•Plaster on lath

▫Similar to gypsum▫Large sections may fall during firefighting

operations.

TERMS

•Load-bearing wall: walls that support structural weight

•Non-load-bearing wall: walls that do not support structural weight.

•Party wall: load-bearing wall that supports two adjacent structures

Load-Bearing Walls

Exterior walls that carry ceiling, roof or upper floor loads to the foundation are load bearing or "bearing" walls. Internal walls that support joists at mid span and transfer loads down to foundations are also bearing walls. Bearing walls usually have perpendicular joists or rafters crossing or resting on top of them and foundations underneath them. An exception are the end walls of a gable-roofed house; these usually run parallel to rafters and joists but must bear the weight of extensive wall framing.Wind and seismic loads, which produce lateral stresses on a house, are managed by tightly interlocking framing members. Plywood sheathing or wood or metal crossbracing interconnect framing members, creating a sturdy triangular form and-together with foundation bolts-lock walls to foundation. The roof is protected from wind uplift by steel strapping.

TERMS• Fire wall: separates two

structures, or divides a structure into smaller portions to prevent the spread of fire.

• Partition wall: non-load-bearing wall that divides two areas within a structure.

• Cantilever or unsupported wall: freestanding firewall usually found in shopping centers or churches.

• Parapet wall: low wall at the edge of a roof.

EFFECTS IN A BURNING BUILDING

•Intense heat▫Causes access problems to firefighters during

operations▫Contributes to fire spread

•Dense smoke▫Hampers firefighting operations▫Proper ventilation is required to ensure:

Removal of smoke Stability of building

EFFECTS IN A BURNING BUILDING•Large volume of water

poured into and on the structure▫Compromises integrity of

construction materials▫Accumulation of water on

the upper floors or roof will add to the live load of an already weakened structure.

Match Roman numeral building construction types to their basic structural characteristics. Write the correct letters on the blanks.

a. Type Ib. Type IIc. Type IIId. Type IVe. Type V

1. __ Wood frame construction 2. __ Non-combustible or limited combustible construction 3. __ Ordinary construction 4. __ Heavy timber construction 5. __ Fire-resistive construction

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HomeworkHomework______ 6. Exterior walls and structural members of noncombustible or limited combustible materials; interior members completely or partially of small-dimension wood; associated fire hazards reduced by placement of fire stops inside concealed spaces______ 7. Construction intended to confine fire and its by-products to a given location; structural members made of noncombustible or limited combustible materials______ 8. Exterior and interior structural members made completely or partially of small-dimension wood and other materials______ 9. Exterior and interior walls and structural members of noncombustible or limited combustible materials; other interior structural members of solid or laminated wood with no concealed spaces; used in old construction of factories, mills, and warehouses______ 10.Lower degree of fire resistance than fire- resistive construction; flat, built-up roofs common feature of this type of construction

a. Type I b. Type II c. Type III d. Type IV

e. Type V

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a. Wood-frame construction

b. Noncombustible or limited combustible construction

c. Ordinary construction

d. Heavy timber construction

e. Fire-resistive construction

____ 11. Almost unlimited potential for fire extension within structure; fire extension to other structures; fire extension from doors and windows to exterior of structure____ 12. Smoke and fire spread through concealed spaces____ 13. Contents of structure____ 14. Massive amount of combustible structural and building contents; exposure protection problems caused by structural members giving off tremendous heat____ 15. Contents of structure; failure of structural supports; failure of flat, built-up roofs often used in this type of construction.

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16. ____ Wall that supports structural weight17. ____ Load-bearing wall that supports two

adjacent structures18. ____ Non- load-bearing wall that divides two

areas within a structure19. ____ Wall that does not support structural weighta) Non Load Bearing Wall b) Partition Wallc) Party Wall d) Load Bearing Wall

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20. ____ Decorative wall; usually attached to the outside of some load-bearing frame or structure

21. ____ Load-bearing wall that separates two connected structures

22. ____ Free standing wall commonly found on large churches and shopping centers.

A) Cantilever WallB) Veneer WallC) Fire Wall

Homework23. ____ Is the presence of large amounts of combustible

materials24. ____ is one of the most critical hazards in commercial and

storage facilities25. ____ Toxic gages produced by burning furnishings and

finishes are major factors in the loss of many lives in fires.26. ____ Combustibility of covering is a concern to entire

community; flaming embers fly from roof to roof easily27. ____ even when treated with fire retardant, significantly

contribute to fire spreada) Combustible Furnishings/ Finishes b) Fireloadingc) Heavy Content Fireloading d) Roof Coveringse) Wood Shake Shingles

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28. ____ Encountered most often in residential construction29. ____ Members fail after only 5 to 10 minutes

30. ____ Are common in warehouses, churches, large atriums, common attics, and theaters

31. ____ Is common construction method in houses, apartments, and small commercial buildings

32. ____ Proper vertical ventilation is essential33. ____ Crews should not go onto the roof after these buildings

have been exposed to fire conditionsUsing answers more than one time, match the correct answer to

the building characteristic described above.a) Large Open Spaces b) Lightweight & Truss Constructionc) Wooden Frames/ Floors/ Ceilings

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34. ___ Includes additional fire load and ignition sources

35. ___ Cracks or separations in walls, floors, ceilings, and roof structures

36. ___ Disabled fire protection systems create potential problems

37. ___ Evidence of existing structural instability

38. ___ Loose bricks, blocks, or stones

Using answers more than one time, match the correct answer to the building characteristic described above

a) Construction hazards b) Renovation/demolition hazards

c) Potential Building Collapse

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39. ___ Unusual creaks and cracking noises

40. ___ Does not have protective features in place yet

41. ___ Structural members pulling away from walls

42. ___ Easy access into building creates arson factor

43. ___ Excessive weight of building contents

Using answers more than one time, match the correct answer to the building characteristic described above

a) Construction hazards b) Renovation/demolition hazards

c) Potential Building Collapse

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44. ___ Are typically found only on older buildings; rarely used in modern construction

45. ___ Large pieces of wood retain much of their original integrity even after extensive fire exposure

46. ___ Will spall or crack if rapidly cooled with fire streams

47. ___ May elongate a 50-foot beam by as much as 4 inches when heated to about 1,000°F

a) Cast Iron b) Masonry c) Steel d) wood

Homework48. ___ The smaller the size, the more likely it is to lose its

structural integrity; smaller pieces may be protected by drywall or gypsum to increase their fire resistance

49. ___ The mortar between masonry materials may deteriorate and should be checked for signs of weakening

50. ___ Elongate when heated and can push out load-bearing walls

51. ___ Include fasteners that hold veneer to building; these fail first, causing large, heavy veneer sections to fall


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52. ___ Chance of collapse is reduced when steel is cooled with water.

53. ___ Impregnated with fire retardants does not ignite or burn as fast as untreated.

54. ___ May crack but usually retain most of their strength

55. ___ Stand up well to fire and intense heata) Cast Iron b) Masonry c) Steel d) wood

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56. ___ Are generally fastened to building fronts as veneer walls

57. ___ Rarely show signs of loss of integrity or deterioration other types may spall or lose small portions of their surface

58. ___ Water applied during fire suppression activities has no significant negative effect.

59. ___ Temperature at which a the member will fail depends on many variables such as: Size, Load, Composition and Geometry


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60. ___ May be wire-reinforced, which provides some thermal protection, but are not an effective barrier to fire extension.

61. ___ Have high water content, the evaporation of which takes a good deal of heat

62. ___ Lose their strength and crack and spall under fire conditions

a) Gypsum b) Fiberglass/ Glass c) Reinforced Concrete

63. ___ Gradually break down under fire conditions, exposing the members behind it to higher temperatures and possible failure

64. ___ May separate from reinforcement material when heat causes the bond between the two to fail

65. ___ When heated, may crack when struck by a cold fire stream

a) Gypsum b) Fiberglass/ Glass c) Reinforced Concrete

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Documents

FVCC Fire Rescue Building Construction. OBJECTIVES 2-9.1 Identify the basic structural characteristics of the following types of building construction: