MH Installers On-Line Continuing Education. Contents of this Course Installation Standard applicable...
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MH Installers On-Line Continuing Education
MH Installers On-Line Continuing Education. Contents of this Course Installation Standard applicable to Pre- April 1, 2007 homes Requirements for steps
Contents of this Course Installation Standard applicable to
Pre- April 1, 2007 homes Requirements for steps Ramps, Steps and
Handrails Refresher on Post-2007 Home Standards SPS 320 Code
Enforcement Refresher Understanding Soils and Frost Heave
Lets Get Started Act 45 laws of 2005 authorized the Department
Commerce (now Department of Safety & Professional Standards) to
adopt installation standards. The UDC applies to both new and used
(relocated) homes. However, the production date as shown on the
data plate determines which code applies.
Slide 5
Pre-2007 Home In this course Pre-2007 means a home build before
April 1, 2007. The applicable code is fairly short and is found in
SPS 321.40. It is linked for you on the course page at
www.housingalliance.us/InstalCE.htm
www.housingalliance.us/InstalCE.htm
Slide 6
Pre-2007 Code Anchoring is a preferred way to protect the home
from the wind. However, if the home is not on a frost protected
foundation, anchors can damage the home. Since frost protected
foundations are not required neither is anchoring.
Slide 7
Pre-2007 Soil Requirements SPS 321.40(2) No footing may be
placed on Unprepared fill material Top soil Alluvial soil Mud All
organic material must be removed
Slide 8
Pre 2007
Slide 9
Soil bearing capacity must be determined so that the footing
can be properly sized. A pocket penetrometer is the least expensive
method
Slide 10
Controlling water is primarily accomplished by grading the
site. Unlike the federal code, grading for Pre 2007 home is only
required for 5 feet around the home. 10 feet however would be
preferred but again not required.
Slide 11
Footings Once the soil bearing capacity is determined the size
of the footing can be determined. The minimum footing size is 16 by
16 inches
Slide 12
Footings If a ABS pad is used, its bearing capacity for a 16 by
16 pad must be 6,000 lbs
Slide 13
Footings There are 4 acceptable types of footings One nominal14
by 6 by 16 inch solid concrete block or two nominal 4 by 8 by 16
inch blocks An 18 inch hole bored below the frost line or to
unfractured soil and filled with concrete A 16 by 16 inch ABS pad
Any other Department approved systems
Slide 14
Piers In a pier where a single block is at the top of the pier
with double blocks below, the double blocks must be positioned with
their joint parallel to the main frame. If a double block pier is
used, the two footing blocks may be positioned with the joint
parallel or perpendicular to the main frame.
Slide 15
Piers A manufactured steel stand is accepted as a pier. Check
its load bearing capacity however before use.
Slide 16
Pier Heights Single stack piers are limited to 36 inches Above
36 inches up to 80 inches double blocks with alternating
orientations are required. Above 80 inches mortar and inch a steel
reinforcing rod is additionally required There is no limit on
height
Slide 17
Pier Placement The maximum pier separation is 7 feet The piers
must be plumb and centered under the contact area at the point of
support The outside piers cannot be more than 3 feet from the
exterior of the home. Additional piers are required in clear span
openings in exterior walls or openings in mating walls of 4 or more
feet
Slide 18
Blocks Must be 2 core design. Cannot be 3 core or solid. Cores
are always placed vertically No concrete block can contact the main
frame
Slide 19
Caps Since concrete piers cannot contact the frame, a cap is
required. Acceptable caps are A solid concrete at least a nominal 2
inches A solid wood block at least a nominal 2 inches The cap must
be the same width and length as the top of the pier A two-piece cap
shall be positioned with the joint perpendicular to the frame The
combined height of the cap material cannot exceed 3 inches
Slide 20
Shims Shims must have a dimension of at least 4 inches by 8
inches They must all be from the same species of wood. (ABS shims
are not allowed) Shims and caps must be at least equal to No. 2
spruce pine and have a fiber bending stress rating of 1200 psi or
better Shims are to be driven in pairs from opposing sides of the
pier
Slide 21
Wood Trees are divided into two classes hardwoods and softwoods
Hardwoods have broad leaves and softwood have needles
Hardwood/Softwood does not describe the hardness of the wood Drying
wood from green to 5 percent moisture in some cases triples its
strength
Slide 22
Wood Force applied to one side of a beam creates compression on
that side and is way to measure strength The following woods have
stress bending rates high enough to meet the 1200 psi rating
Douglas Fir Hemlocks Spruce Pine Fir but only select, no. 1 or no.
2 Spruce Pine Fir no 3 would not be acceptable
Slide 23
Clearance A minimum clearance of 12 shall be maintained under
at least 75% of the home. (For homes built on or after 4/1/2007 the
entire clearance area must be 12) This is the end of the Pre-2007
Home Installation Code Section
Slide 24
Stairs, Steps, Railings Consult SPS 321 Stairway leading to
non-habitable attics or crawl spaces are not covered by the UDC
Generally, stairways must measure at least 36 in width
Slide 25
Spiral Stairs Often not just a decorative feature but a space
necessity. Spiral staircases shall be at least 26 inches wide
measured from the outer edge of the supporting column to the inner
edge of the handrail. At the top and bottom of a flight,
measurement shall be taken from the top of the nosing to the
finished floor surface unless the finished surface is carpeting, in
which case measurement shall be made to the hard surface below the
carpeting.
Slide 26
Except for spiral staircases risers may not exceed 8 inches in
height measured vertically from tread to tread. Risers in spiral
staircases may not exceed 9.5 inches in height measured vertically
from tread to tread. Rectangular treads shall have minimum tread
depth of 9 inches measured horizontally from nosing to nosing.
Slide 27
Headroom Stairways shall be provided with a minimum headroom
clearance of 76 inches measured vertically from a line parallel to
the nosing of the treads to the ceiling, soffit or any overhead
obstruction directly above that line. The headroom clearance shall
be maintained over a landing that is at the top or bottom of a
stairway for a minimum distance of 36 inches in the direction of
travel of the stairway.
Slide 28
Variance in Height Within a stairway flight, the greatest tread
depth may not exceed the smallest tread depth by more than 3/8 inch
and the greatest riser height may not exceed the smallest riser
height by more than 3/8 inch. WOW!
Slide 29
The walking surface of stair treads and landings shall be a
planar surface that is free of lips or protrusions that could
present a tripping hazard. Stairways leading to non-habitable
attics or crawl spaces are not covered by the UDC. Generally,
stairways shall be at least 36 inches wide.
Slide 30
Common Defects Openings in handrails/guardrails Gripping
surfaces on handrails Headroom Uniformity Landings
Slide 31
Cable or Ropes If cables or ropes are used in a handrail or
guardrail shall be strung with maximum openings of 3 inches with
vertical supports 4 feet Incorrect opening exceeds 3 inches
Slide 32
Stairways with open risers shall be constructed to prevent the
through-passage of a sphere with a diameter of 4 inches or larger
between any 2 adjacent treads.
Slide 33
Design Standards Handrails and guardrails must be designed to
withstand a 200 lb load applied in any direction. Any glazing used
must be safety glazing Exterior handrails and guardrails must be
made of metal, decay resistant or pressure treated wood, or shall
be protected from the weather.
Slide 34
Handrails Forms A common violation regarding decks and stairs
involves handrail shapes. Must be symmetrical at the vertical
centerline to allow for equal wraparound of the fingers and thumb.
Where the handrail is round or truncated round cross sectional
gripping surface must have a whole diameter of 2 inches. 2
inches
Slide 35
Continuity Handrails must be continuous for the entire length
of the stairs except: At an intermediate landing A handrail may
have newel posts At an intermediate wall provided the upper rail is
returned to the wall or provided with a flared end, The horizontal
offset between the 2 rails is no more than 12 measured from the
center of the rails, and Both upper and lower rails can be reached
from the same tread without taking a step.
Slide 36
Landings An intermediate landing is required in any stairs that
has a height of 12 feet or more. Intermediate landings connecting
straight stairs or stairs at a right angle must be as wide as the
stairs and measure at least 36 inches in the direction of travel.
Curved or irregular landings shall have a radius of at least 36
inches.
Slide 37
Landings The level landing at the top and base of every stairs
shall be as wide as the stairs and shall be at least 3 feet in the
direction of travel A landing is not required between the door and
top of the interior stairs if the door does not swing over the
stairs Between a sliding glass door and the top of an exterior
stairs of 3 or fewer risers
Slide 38
Landings The exterior landing, platform or sidewalk at an
exterior doorway shall not exceed 8 inches below the interior floor
elevation and shall have at least 36 inches of surface in the
direction of travel
Slide 39
Ramp Landings A level landing shall be provided at the top, at
the foot and at any change of direction of the ramp. The landing
must be at least as wide as the ramp and shall measure at least 3
feet in the direction of travel.
Slide 40
Ramps Ramps shall not have a slop greater than 1 in 8. (One
foot of rise for each 8 feet of run.) Walkways with a slope of less
than 1 in 20 are not considered ramps. Ramps must have a slip
resistant surface.
Slide 41
Clearance The clearance between the handrail and a wall shall
be at least 1 inches. Handrails and their trim can project a
maximum of 4 inches into the required width of the stairs or
landing.
Slide 42
Required Handrails When the ramp has a gradient greater than 1
in 12 AND which overcomes a change in elevation of 24 inches or
more, shall have a handrail on both sides. Every ramp that
overcomes a change of elevation of 8 inches or more shall have at
least one handrail. Handrails shall be located to the top of the
handrail is at least 30 inches but not more than 38 inches above
the ramp surface.
Slide 43
Openings in Handrails The opening in a handrail shall prevent
the passage of a sphere with a diameter of 4 inches or larger. The
triangular area formed by the tread, riser or guardrail shall have
an opening that prevents the passage of sphere of 6 inches or more
This design is decorative but openings exceed 4 inches. This
completes the section on stair, ramps and handrails
Slide 44
Federal Installation Standard Each state must adopt a version
that is at least as stringent as the federal model code. Each
manufacture must provide 2 sets of instructions At least 1 method
for temporary support when sited at the plant, retailers lot or
home site Instructions for the installation of the home
Slide 45
Federal Installation Standard An installer must follow the
temporary set instruction until the home is placed on its
foundation Failure to support the home while stored could result in
structural damage
Slide 46
Federal Installation Standard Variation to the installation
instructions by an installer is not permitted unless permitted by
the manufacturer, a professional engineer or architect. Any
alteration to the instructions must not impose additional loads to
the home or its foundation
Slide 47
Federal Installation Standard The installation standard applies
to manufactured homes only not Modular homes RVs A manufactured
home is defined in federal law as 8 body feet or more in width or
40 body feet in length or when erected is 320 or more square feet
(additional requirements can be found in the definitions section of
the code)
Slide 48
Federal Installation Standard Before placing the home on the
site consider the impact of: Fire separation distances as may be
required by NFPA 501A and any local requirements The existence of
flood plains Wind zone Roof load zone And the Thermal zone
Slide 49
Caps this section is unique to WI* Acceptable caps are* A
combination of up to two-4 thick concrete blocks and not more than
one-2 hardwood lumber. Lumber must be at the top of the pier. A 4
block cannot be the bottom block in the pier but by be mixed with
other blocks
Slide 50
Caps The cap must be the same width and length as the top of
the pier A two-piece cap shall be positioned with the joint
perpendicular to the frame
Slide 51
Federal Installation Standard The location and spacing of piers
depends upon: The dimensions of the home Live and dead loads Soil
bearing capacity I-Beam size Footing size Factors such as location
of doors/windows Unlike the WI Standard for Pre-2007 homes the
maximum spacing is 10 ft unless the manufacturer provides for a
greater distance
Slide 52
Federal Installation Standard A single stack concrete pier load
must not exceed 8,000 lbs The concrete blocks must conform to ASTM
C-90 Prior to 2000, ASTM C90 included two different type
designations for concrete masonry units: Type I units were defined
as moisture-controlled units; Type II units were defined as
non-moisture controlled units. All units must still comply with the
requirements for minimum compressive strength, maximum water
absorption, maximum variation in dimensions, face shell thickness,
web thickness, equivalent web thickness, and maximum linear drying
shrinkage exactly as they had before the removal of type
designations.
Slide 53
Pay special attention where a mating wall does not support the
ridge beam this is considered an unsupported span Where there is an
open span that is greater than 10 ft, an intermediate pier is
required 10 ft on center despite the fact there is no direct
support above to the ridge beam Piers can be off set up to 6 to
clear plumbing, electrical, mechanical, crawspaces or other
devices
Slide 54
Federal Installation Standard If outriggers or floor joists are
used as an alternative to perimeter supports, the loan design must
consider the additional loads when sizing the pier and footings The
end piers under the I-Beams may be setback from the outside edge of
the home a maximum of 24 (This compares to 36 in the Pre-2007 code.
This ends the Federal Installation Standard section
Slide 55
UDC Enforcement SPS 320 The UDC is a minimum-maximum code
meaning that a municipality may not adopt an ordinance on any
subject within the scope of the UDC including restrictions on
occupancy for any reason other than noncompliance with the Code. A
municipality cannot adopt that are less stringent that the UDC
Installation of manufactured home is a part of the UDC.
Slide 56
UDC Enforcement Is broader than just one and two family
dwellings, adult family homes providing care, treatment and
services for 3 or 4 unrelated adults are also covered by the UDC.
Additions and alterations may be covered by the code at the option
of municipality Determining if the code applies to an addition or
alternation is whether the ordinance doing so was in effect at the
time of permit application or the beginning of the project if no
permit is required