Transcript Presentation 2 - Wisconsin Housing Alliance

Installation Codes
Manufactured Home Installer Course
Part 2
1
Licensing for Installers
 What’s been the Timeline?
 Jan 1, 2007 –licensing began
 April 1, 2007 – new installation code
effective and inspections began
2
Licensing
 You need a license to install a home on a
foundation. If you ONLY do the following
no license is required:




Anchoring – no
Grading – no
Excavation – no
Pouring basement – no
 The person supervising the home going on
the foundation - yes
3
Licensing
 Your license is subject to the
requirements for General Supervision
– the installer does not need to be on
the job site but must be available to
the building inspector
 Homeowners are exempt from
licensing but if people help and would
otherwise need a license they must
be licensed
4
Licensing of Installers
 Qualifications
 18 years old
 Not been found responsible in any court
or agency hearing of a violation of the
installation law during prior 2 years
 Not been found responsible in any court
or agency hearing for failure to perform
under installation contract or defrauding a
person in the provision of installation
services
5
Application for Installers
License
 A state license fee plus one time
application fee for 4 year license
 Take 12 hour qualifying class & pass
exam
6
Renewal
 Renewal requires 12 hours of
continuing education over the 4 year
period
 Also must not have been found
responsible for breaking the rule or
defrauding a customer
7
Wisconsin Installation Standard
 Act 45 laws of 2005 authorized the
Department Commerce to adopt
standards
8
Comm 21.40
 Formerly Comm 27.18
 Now a part of the UDC
 Applies to homes built before April 1,
2007
April 1, 2007

Comm 21.40 applies
Part 3285 applies
Home Built before April 1
Home Built on or after April 1
Code starts on page 9 of your workbook
9
All Pre April 07
Homes follow
Comm 21.40
10

Even this one!
11
Comm 21.40
 Review pages 9 and 10 of your
workbook for all of the details
regarding the code for Pre-April 1,
2007 built homes.
12
Comm 21.40 for homes before
4/1/2007
 No footing on unprepared fill. All
organic matter must be removed.
 Soil bearing test using pocket
penetrometer
 Grade site to drain water away for
minimum of 5 ft from home
 A footing for every pier, nominal 16”
by 16”
 Consult others if soil is less than 2000
psi
13
Comm 21.40 Footings
 one 4 by 16 by 16 solid blocks or two
4 by 8 by 16 solid blocks.
 16 by 16 ABS pad rated at not less
than 6000 lbs
 18 inch diameter hole bored below
the frost line or to unfractured
bedrock and filled with poured
concrete

Other materials or systems approved by Commerce
14

Note: frost protection not required
ABS Pads
 ABS pads
are
permitted for
homes built
prior to April
1, 2007.
 The
honeycomb
always faces
up
15
Not all ABS Pads are the Same!
4755
lbs/sq ft
4000
lbs/sq ft
5000
lbs/sq ft
In 2000 pfs soil, the capacity of each pad is as shown
above, also the direction of a single stack of blocks is
specified on the back with arrows.
16
Comm 21.40 Piers
 Concrete blocks, manufactured steel
stands or manufactured concrete stands
 Single stack piers limited to 36 inches
 Single stack piers loads limited to 8,000
lbs
 36 to 80 inch piers – double blocked
(layered in opposing layers)
 80 inch or more – double blocked laid in
concrete mortar, cores filled with mortar
and ½ inch steel reinforcing rod*

Note mortar and reinforcing rod is more
stringent than Part 385
17
Comm 21.40 Concrete Blocks
 2 core design, construction grade
8x8x16
 Cores placed with cores open
vertically
 Block nearest main frame shall be
perpendicular to the linear direction
of frame
 No block may contact the frame
18
Comm 21.40 – Pier Spacing
 No more than 7 feet on center
 No more than 3 feet from exterior
side of each end wall
 Can be varied to follow manufacturer
tables
 Piers under clear-span openings of 4
feet or more in mating walls
 Piers must be plumb and centered
under point of support
19
Comm 21.40 - Caps
 Solid concrete block or solid wood
block having nominal thickness of at
least 2 inches
 Cap must be same width and length
as top of pier
 No more than 2 pieces – 2 piece caps
positioned with joint perpendicular to
frame if used
20
Comm 21.40 - Shims
 Where used, driven from opposing
sides and be no less than 4” by 8”
 Wood caps and shims at least equal
to #2 spruce pine fir with min
bending stress rating of 1200 psi. All
wood caps must be of same species
of wood. All shims must be of same
species of wood.

Note - shims not required but concrete blocks cannot
contact the frame.
21
Comm 21.40 – Height limits
 Combination of nominal 2
inch solid concrete block or
wood cap plus shims must
not exceed 3 ½ inches

Minimum clearance under home of 12 inches between
lowest point of main frame in area of utility connections.
Min clearance of 12 inches for 75% of home. Remainder
may be less than 12 inches but cannot touch ground
22
Recap on 21.40 on key items







All organic matter removed
Proper drainage
7 foot maximum spacing between piers
Construction grade blocks
Any hardwood used must be the same species
If ABS pads used, honeycomb is up
Double stacked blocks above 36”
23
Federal Installation Standard
 Known as Part 3285 this code applies
to home built on or after April 1,
2007.
 The Wisconsin changes are noted in
the text in your binder – latest
changes were 3/19/09
24
The Standards
 3280 – HUD Construction Standards
for the home
 3285 – HUD Model Installation
Standards
 The following must be AT LEAST AS
STRINGENT as the federal model
 State Standards
 Manufacturer Manuals
25
Understanding Part 3285
 Use the Blue and Red Cheat Sheet
 This Key to the Code will help you
find applicable sections as you use
the code quicker!
26
Definitions
 Words have meaning so read them
carefully – see 3285.5
 For example, an anchor is a part of
an anchoring system.
27
DAPIA
 DAPIA – means Design Approval
Primary Inspection Agency
 A manufacturer must provide with
each new home a DAPIA approved
designs and instructions that are
consistent with the standards –
3285.2
28
Application of the Standard
 These standards apply to HUD
Code manufactured Homes not
modulars.
29
Fire Separation
 Fire separation distances in accord
with NFPA 501(a) must be
maintained. Means 10 feet
 Fire separation distance must also
comply with Comm 26 in a mobile
home park
(10 feet between basic
structures)
 Local ordinances might have
additional requirements
30
Flood Zones
 Installer is responsible to
determine if home is being
installed in flood zone.
3285.102(c) – Contact the zoning
administrator for the county
 If it is, special installation methods
are required.
 Note there are also Shoreland
zoning implications
31
Zone Maps
 3 maps in the HUD Code
 Wind – Wisconsin in Zone 1
 Roof Load – Wisconsin is South and
Middle Zones
 Thermal Zone – Wisconsin is Zone 3
 U/O value must be less than 0.079
 U/O is inverse of R value 0.079 = R 12.6
 Homes may not be installed in a wind
zone that exceeds the design load for the
home.
32

See pages 11 & 12 in your workbook
Site Preparation
 Soil tests can be conducted with a pocket
penetrometer
 Footings must be sized and spaced
according to soil bearing capacity
 See the tables in 3285.202
 Poor soils – peat, organic clays or
uncompacted fill require a geologist,
engineer or architect’s opinion
33
Site Drainage
 Drainage must be provided to direct
surface water away from home and
prevent build up under home.
 Minimum slope of ½ inch per foot for
the first 10 feet for homes built on or
after April 1, 2007 and 5 feet for
older homes.
 Where site is sloped, home must be
protected from surface runoff
34
Crown and Grade Site
35
36
Controlling Water is Critical
37
Gutters and Downspouts
 Manufacturer must specify if the
home is designed for gutters and
downspouts
 When installed, runoff must be
directed away from the home
38
Ground Moisture Control
Vapor barrier must be installed
Min. 6 mill poly or equivalent
Overlap 12 inches and seal
Barrier may be under, over or around
footings
 Voids and tears must be repaired





3285.204
39
Ground Moisture Control
 1 pint of water vapor is generated
in 24 hours
 @ 55 degrees under 10 sq. ft of
floor area. 1500 sq ft home then
equals 150 pints of water. That’s
16-19 gallons of water
40
Foundations - Piers
 Concrete blocks – Must conform to
ASTM standard C 90-02
 Pressure treated wood – think pilings
 Adjustable metal - Manufactured
piers must be labeled or listed for
loads and installed to the pier
manufacturer’s instructions
41
Pier loads
 Must be designed with load taken into
consideration
 Spacing is dependant on factors such
as soil bearing capacity and foot size
 See tables at 3285.303
 Pier spacing tables do not take into
consideration flood or seismic loads
42
Pier Configuration
 Load bearing blocks not decorative
 Nominal 8 by 8 by 16 inches
 Stacked with hollow cores aligned
vertically
 When stacked side by side, each
layer at right angles to preceding one
 Center beam/mating line supports are
always required for multi-section
homes

Primary failure regarding piers is insufficient sizing of mating
line piers under ridge beam openings
43
A single block pier requires a
minimum 18” diameter footing!
44
No part of the pier can overhang the
footing!
45
Caps
 Must evenly distribute loads across the
capped hollow block piers
 May be made of solid concrete or
masonry at least 4 inches nominal
thickness OR
 hardwood lumber at least 2 inches thick
46
Caps
 Must be same length and width as
piers
 Split caps on double stacked piers
must be installed with long dimension
across the joint in blocks below
47
Gaps
 Must be filled
 Options
2nd 4” concrete block but cannot contact
frame
Nominal 4 by 6 by 1 inch shims

•
a.
b.
c.
Must be used in pairs
Driven tightly
Must not occupy more than 1 inch of
vertical space
48
Manufactured Piers
 Adjustable risers
must not extend
more than 2 inches
when finally
positioned
49
Clearance under Home
 Minimum of 12 inches between lowest
member of main frame and grade under
all areas of the home
 Comm 21.40 for older homes is
A minimum clearance of 12 inches shall be maintained
beneath the lowest point of the main frame in the area of
any utility connection. A minimum clearance of 12 inches
shall also be maintained under the home for at least 75%
of the home. The remainder of the home may be less
than 12 inches above the ground but may not touch the
ground.
50
Less than 36” Piers
 Permitted to be constructed of open or
closed cell 8 by 8 by 16 when capacity
of block is not exceeded
 Long sides are at right angles to
supported I-beam
 Hollow cores stacked vertically
 Horizontal offsets from top to bottom
not to exceed ½ inch
 No mortar unless instructions require
it
51
52
53
Piers 36 to 67” and Corner Piers
 All frame piers 36 to 67” high and all
corner piers over 3 block high must
be double blocked
 No mortar unless instructions require
 Horizontal offsets not to exceed 1”
54
55
56
Hardwood plate must
run in same
direction as
concrete cap
Bottom 2 courses must
be spun around
57
Perimeter support piers
 Piers at mate-line supports, perimeter
piers, and piers at exterior wall
openings can be single open-cell or
closed cell blocks to a maximum
height of 54 inches
 Must be installed with the long
dimension parallel to perimeter rail
58
Pier Support Locations
 No more than 24 inches from both
ends of frame
 No more than 120 inches center to
center under the main I beam
 Mating line, marriage wall line, ridge
beam all mean the point where
sections join and they require support
– Be alert to extreme weight
considerations in these locations!
59
Perimeter Support Locations
•
•
•
Both sides of any exterior door
Any side wall opening of 48 inches or
more
Under any load-bearing porch posts,
factory installed fireplaces and wood
stoves
3285.311
60
Alternative to Perimeter
Supports
 If additional floor joists or outriggers
are providing perimeter support, the
sizing of piers and footers under the
main chassis beam must be adjusted.
61
Footings
 Must be located on undisturbed soil or
fill compacted to 90% of maximum
relative density
 A footing for every pier
 Footing size depends on the load
bearing capacity of soil, footings and
piers

3285.312
62
Footing Types
 Concrete types
 4 inch nominal precast pads meeting
ASTM C 90-02 with 28
day compressive
strength of 1,200 psi
 6-inch minimum
poured in place
concrete pads or slabs
with at least 28 day
compressive strength
of 3,000 psi

Bad footing
63
Footing Types
 ABS footing pads – not really applicable for
new homes since no frost protection
 Installed according to pad manufacturer
instructions and certified for use in soil
classification at the site
 Must be listed for required load capacity
 Treated Wood – not really applicable since
limited frost protection except for elevated type
installations (pilings)
64
Frost Protection
Only 3 ways in Wisconsin to install a post April 07 home
 Footings must be designed using
methods and practices that
prevent the effects of frost heave
by:
1. Conventional below the frost line
footing
2. Monolithic slab above frost line –
Commerce has issued
acceptable design
3. Insulated foundation system
above frost line
3285.312
Frost line is 48 inches statewide as set
by Commerce
65
Acceptable Slab Design
 Seal is not required in Wisconsin
version of installation standards per
Comm 20.09(4)b
 Larry Swaziek of the Department of
Commerce issued an Acceptable Slab
Design
 (see page 94-95 in your workbook)
66
Acceptable Slab Design




6” thick
10” thickened edge with rebar
Min 3000 psi concrete
Make sure you read the footnotes for
design limitations very carefully
67
68
69
Footing Sizing Table
 How to use the tables
 Use soil bearing capacity to
determine size and thickness
needed
70
This is a simplified pier plan for a home – 3 of the I-Beams are deleted
Calculate Bearing Points
for clarity
Note that the marriage line
piers are not equal distance
apart
71
This is a simplified pier plan for a home – 3 of the I-Beams are deleted
Calculate Bearing Points
for clarity
Write down all of the weights
that exceed 5300 which is the
capacity of a 6 inch thick slab
72
Look at the chart on the next page and
note the following things:
1. Your soil bearing capacity – this
section the table from pages 37-38
of your manual assumes 2000 psf
soil.
2. What is your roof load zone? For our
example we’ll use 30 psf.
3. What is the pier spacing you want to
use?
73
Table 1 – Frame only blocking
Pier Spacing
4 ft
6 ft
8 ft
10 ft
Roof Live Load
Location
Load (lbs)
20
Frame
2900
30
Frame
3300
40
Frame
3600
20
Frame
4200
30
Frame
4700
40
Frame
5200
20
Frame
5500
30
Frame
6200
40
Frame
6900
20
Frame
6800
30
Frame
7600
74
Table 1 – Frame only blocking
Pier Spacing
Roof Live Load
Location
Load (lbs)
All under 8000
4 ft
2000 pfs soil
6 ft
8 ft
10 ft
Pages 37 - 38
20
Frame
2900
30
Frame
3300 ok
40
Frame
3600
20
Frame
4200
30
Frame
4700 ok
40
Frame
5200
20
Frame
5500
30
Frame
6200 NO
40
Frame
6900
20
Frame
6800
30
Frame
7600 NO
75
Keys
 Don’t exceed 8,000 lb capacity of
single stack of blocks or 16,000 lb
capacity of double stack
 If print shows required perimeter
support make sure it is present
 Concentrate on largest loads first
usually the mating line

A + B dictates C
76
3 factors to consider



A. soil bearing capacity
B. pier spacing
C. footing size
A + B dictates C
77
Footing tables
 On pages 55-57
 You can read these tables the same
way.
78
Footing Sizes –
Table on Pages 55 -
56
8 by 16 in. pier
16 by 16 in pier
Soil
Capacity
Min
Footing
Size
Max
Footing
Capacity
Min
Max
Thicknes Footing
s
Capacity
Min
Thicknes
s
2000
16 x 16
3,400
6
3,400
6
20 x 20
5,300
6
5,300
6
24 x 24
7,600
8
7,700
8
30 x 30
11,600
10
11,900
10
36 x 36
16,300
15
16,900
10
42 x 42
21,700
18
22,700
12
79
 A 6 inch slab cannot be used under
portions of this home that exceed
5300 lbs
 That means the marriage line area
must be thickened
 For below the frost line footings, pier
loads above 3400 lbs require double
blocking and larger footings that 16 x
16.
80
Calculate
Pointsthe Foundation
Let’s Use theBearing
Tables to Design
Note the load amounts
If this is a slab set note that
mating line must be more
than 6” thick per tables
81
Biggest Load –
Table on Pages 55 -
56
8 by 16 in. pier
16 by 16 in pier
Soil
Capacity
Min
Footing
Size
Max
Footing
Capacity
Min
Max
Thicknes Footing
s
Capacity
Min
Thicknes
s
2000
16 x 16
3,400
6
3,400
6
20 x 20
5,300
6
5,300
6
24 x 24
7,600
8
7,700
8
30 x 30
11,600
10
11,900
10
36 x 36
16,300
15
16,900
10
42 x 42
21,700
18
22,700
12
Footer 24 x 24 satisfies 7000 lb mating line load for below the
frost line footings
82
Biggest Load –
Table on Pages 55 -
56
8 by 16 in. pier
16 by 16 in pier
Soil
Capacity
Min
Footing
Size
Max
Footing
Capacity
Min
Max
Thicknes Footing
s
Capacity
Min
Thicknes
s
2000
16 x 16
3,400
6
3,400
6
20 x 20
5,300
6
5,300
6
24 x 24
7,600
8
7,700
8
30 x 30
11,600
10
11,900
10
36 x 36
16,300
15
16,900
10
42 x 42
21,700
18
22,700
12
83
8” Slab thickness satisfies 7000 maximum load on mating line
Biggest Load –
Table on Pages 55 -
56
8 by 16 in. pier
16 by 16 in pier
Soil
Capacity
Min
Footing
Size
Max
Footing
Capacity
Min
Max
Thicknes Footing
s
Capacity
Min
Thicknes
s
2000
16 x 16
3,400
6
3,400
6
20 x 20
5,300
6
5,300
6
24 x 24
7,600
8
7,700
8
30 x 30
11,600
10
11,900
10
36 x 36
16,300
15
16,900
10
42 x 42
21,700
18
22,700
12
84
20 x 20 or 6” slab satisfies all other loads
Tables Assume Square Footings
It is a major mistake to read the footing
tables in square dimensions and not
properly translate those figures to a
round bored hole.
85
Translating
□ to O
Area of a circle is:
PI x radius of circle
Quick Calc
3.14 x (9 x 9) = 254
Diameter is 18 inches
18” circle = 254 inches
20” circle = 314 inches
24” circle = 452 inches
Radius is 9 inches
Thus 20” diameter is not close to 20” square.
314” vs 400” – you need a 24 inch bored hole
86
Anchorage
 After blocking and leveling, the manufactured
home must be secured against the wind by an
anchoring system
 Anchoring equipment means ties, straps, cables,
turnbuckles, chains and other approved
components including tensioning devices that are
used to secure a manufactured home to anchor
assemblies.
 Conventional anchors or alternative foundation
system (Tie Down or Oliver Technologies type
systems)
87
Tie Downs
 Maximum spacing – see
the tables
 See drawings for near
beam and second beam
methods
 If sidewall or over the
roof, mate-line or shear
wall straps are installed,
they must be connected
 Must be augured at least
30 inches unless the
foundation is a frost
protected above frost
line system
88
Tie Down Straps
 1 ¼ inch by 0.035 in or larger steel
strapping conforming to ASTM D 395397 standard
 Capable to resist a min ultimate load of
4750 lb and a working load of 3150 lbs
(check listing labels) – Same capacity
as the anchors
 Coated with zinc to not less than 0.30
oz/ft2 of surface
89
Tie Down Tips
 No long tails
 Tension evenly or you might pull the
home off the supports
 Determine if stabilizer plate is needed
– See anchor manufacturer
instructions
 Try locking clamp version
90
Anchorage
 The anchors must be capable of meeting
the loads the home was designed to
withstand – see data plate
 Follow the anchor company’s instructions
for spacing, angles, connections and so
forth
 Install anchors to their FULL depth
 A diagonal anchor tie is intended to resist
horizontal or shear forces, but may also
resist vertical, uplift and overturning
forces
 3285.401
91
Ground Anchors
 Must be listed (listed means
approved)
 Steel coated and weather protected.
HUD now allows either zinc coated or
painted anchors.
 Capable to resist a min ultimate load
of 4750 lb and a working load of 3150
lbs (check listing labels)
92
Tie Down Engineering
Vector System
Several companies have alternative systems that work without anchors
93
Vector System with
Longitudinal Support
94
Note base plate and longitudinal support
Tie Down Safety Issues
 Locate Utilities
 abandoned electrical drops is a concern
 utility lineman’s gloves are
recommended
 Test for power on anchor before
connecting to home can be done using a
simple voltage checker
$5.25 worth of
safety
95
Image courtesy of Lab
Safety, Janesville
On-site structures
 Each expansion room or other on-site
structure must be able to support its
own weight including any garage
unless pre-designed by manufacturer,
engineer or architect
 Any addition must be designed by
either the home manufacturer, a
registered engineer or architect
96
Did the manufacturer approve this addition?
97
Optional Equipment
 Comfort systems (HVAC) must be installed
by a licensed HVAC contractor if not factory
installed
 Air conditioning equipment must be
properly sized
 All heat producing equipment must be
properly vented thru the skirting or exterior
wall as appropriate
 When not installed by home manufacturer,
must be installed according to the appliance
manufacturer’s instructions
98
Skirting

Must be weather resistant

Attached so no water is trapped
between siding and trim or forced
up into the wall cavity trim

All wood skirting within 6 inches of
the ground must be pressure
treated or be naturally resistant to
decay and termites – This would
include lumber and sheathing
extension if any of the wood is less
than 6 inches above the ground
99
100
Crawlspace Venting
 NEW - One square foot for every 1,500 sq
ft of floor area – Important – Check with
your manufacturer before proceeding with
reduced venting
 Vent openings as high as practicable
 Vents must located on at least two opposite
sides of home
 Openings must be covered with a
perforated corrosion and weather resistant
covering to prevent rodent entry
101

Front OK
102
103
104
Which vent panel permits the
most free air to pass through?
105
The Answer is A
 This panel has a large number of
openings which although they are
small allows more air to pass than the
other panels which have much more
hard surface area. Panels are rated,
see the back of any panel you buy to
know what you are getting.
106
Access Openings MUST:
 Not less than 18 wide by 24 high and
not less than 3 sq ft
 Must be located so that any utility
connections under the home are
accessible
107
3285.505
108
Dryer vents, air conditioning, &
combustion air vents
 Must pass through skirting to the
outside
 This includes fireplace air inlets
 Air conditioner equipment not
installed by the manufacturer must
be done by a person holding an HVAC
license!
109
Ductwork, Plumbing & Fuel
Supplies
 Manufacturer must supply
instructions for proper field assembly
110
Water
 When local water supply pressure exceeds
80 psi, a pressure reducing value must be
installed
 An identified and accessible shutoff value
must be installed underneath or adjacent
to the home
 Crossovers and lines must be protected
from freezing
 Only listed MH heat tape is permitted
 Water system must be inspected and
tested for leaks after completion at the
site.
 Disconnect water heater if test is air only
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Piping support
 Water lines supported every 3 feet
 Drain lines supported every 4 feet –
See 48 inch on center max 3280.608
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Gas Supply
 Home design calls for system
pressure of 10 to 14 inches of
water column pressure (0.036
psi)
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Ductwork Crossovers
 All ductwork connections must be
sealed
 Galvanized metal straps or tape and
mastics listed to UL 181 A or B must
be used around duct collar and
secured tightly
 Metal straps require metal sheet
screws
 Fasten with at least 3 galvanized sheet
metal screws equally spaced around the
collar
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Ductwork
 Max distance for duct supports is 4 feet
 If straps are used they must be ½” wider than
spacing of spirals in flex duct
 Arrange so that straps cannot slip between
spirals and to prevent kinking
 Ducts cannot contact ground
 Listed for exterior use only
115
Ductwork
 Crossovers outside the envelop must be
insulated with proper materials
 In-floor or ceiling crossover connections
must be sealed to prevent air leakage
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Subpart H - Electrical
 Snap connections may or must be
fastened to adjacent stud – CHECK
instructions
 If a fixture is mounted on a
combustible surface a limited
combustible or non-combustible ring
must be installed
 Wires connected black to black, white
to white and ground to ground
 Test all connections
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Smoke Alarms
 Additional shipped loose alarms for
basement set models are typically
provided by the manufacturer
 They may be wired to communicate
with factory installed units at main
floor
 A separate WI law also requires
carbon monoxide detectors
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Exterior close-up
 Manufacturers provide instructions for
joining sections. Pay particular
attention to directions on fasteners
 The mate-line gasket must be
installed following manufacturer
instructions
 Exterior close up strips are trim that
must be fastened securely and sealed
with an exterior sealant
119
Before Sections are Secured
 The poly sheeting used for transport
must be removed completely
120
Hinged roofs and eaves
 May be
subject to
alternative
construction
inspections if
flue
penetrations
are above the
hinge
No Seal!
121
Gaps
 UPON COMPLETION – no gaps are
permitted between structural elements
 PRIOR TO COMPLETION – minor gaps not
exceeding one inch are permitted
PROVIDED they are filed upon completion
122
Gaps
 Fill gaps must be shimmed with
dimensional lumber and fastener lengths
used to make connections must be
increased to provide adequate penetration
into receiving lumber.
 Pay particular attention to end wall and
floor completion gaps – May have
marriage wall sheathing in from end wall
ends
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Close up
 All shipping blocking, strapping or
bracing must be removed from
appliances, window and doors.
 At a minimum, shipped loose wall
panels must be installed using PVA
adhesive on all framing members and
fastened with 1 inch long staples or
nails 6 inch on center panel edges and
12 inches on center in the field unless
manufacturer directs other methods
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Bottom Board
 Bottom Board is an industry term for
barrier installed by the factory on the
bottom of the floor system. It is for rodent
control.
 Inspect for loosing or areas damaged by
transport or installation
 Tears must be repaired
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Bottom Board
 Any missing insulation must be
replaced
 Splits or tears must be resealed with
tape or patches
 P traps must be checked to be sure
they are well insulated and covered
 All repaired edges must be taped or
otherwise sealed
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Other UDC Issues to Watch
 Site constructed elements subject to
UDC
 Basement stairs
 Exterior decks, stairs and railings
 Garage attachments
 Habitable basements
 Egress windows for bedrooms
 Heating calculations for entire envelop
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Trouble spots-Basement Stairs
Maintain 6'-4" Headroom In
Required 3' Long Landing
Finished Stairwell Length (FSL)
Floor/Ceiling
Depth
Headroom
(Min. 6'-4")
Two Similar
Right
Triangles
Maintain
6'-4"
Headroo
m In
Required
3' Long
Landing
Headroom + Floor/Ceiling Depth (HFCD)
Unit Rise
So to solve for FSL, FSL = Unit Run x HFCD
Unit Rise
Unit Rise
Max. 8"
Unit Run
Min. 9"
Finished Stairwell Length(FSL)
Unit Run
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End
 Return to MH Installer Course Click
here
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