Manufactured Home Installer
CE Course
• Approved by the Department of Safety &
Professional Services – Approval #
• Presented by the Wisconsin Housing Alliance
Contents of this Course
• SPS 321 Code Enforcement Refresher
– Glazing
– Ventilation
– Fire protection
– Preserved wood
• Installation Standard applicable Post-2007
Home
• Soils
• Piers, Shims & Caps
Primary Resources
• UDC Code SPS 321
• Installation Code (engrossed version of Part
3285 with Wisconsin Amendments
• Soil Classification Information
• Slides
Let’s Get Started
• The UDC applies to both new and used
(relocated) homes. (However, the production date as shown
on the data plate determines which installation code applies.)
• Act 45 laws of 2005 authorized the
Department Commerce (now Department of
Safety & Professional Standards) to adopt
installation standards.
• The UDC applies to additions to manufactured
homes including garages, exterior decks and
steps.
Glazing Requirements
• Glazing is not often a consideration for home
installers but it can be if a door or window is
altered.
• Both the UDC and the HUD Code have a
general rule that glazed openings shall be at
least 8% of the gross floor area. (3280.103 and
SPS 321.05
• The HUD Code has no exceptions but the UDC
does.
Glazing
• UDC glazing exceptions
– Habitable rooms, other than bedrooms, located
in basements or ground floors do not require
natural light.
– Natural light may be obtained from adjoining
areas through glazed openings, louvers or other
approved methods.
UDC Glazing
• Door openings into adjoining areas may not
be used to satisfy the 8% standard.
• Natural ventilation is required in all habitable
rooms
HUD Ventilation
• Each manufactured home must have whole
house ventilation with a capacity of 0.035
ft3/min/ft2. This is in addition to any openable
window area.
• The ventilation system must not draw or expel
air into the floor, wall or ceiling/roof systems
Ventilation
• Natural ventilation can be provided by:
– Openable doors (UDC only)
– Openable skylights (UDC only)
– Openable windows (UDC & HUD)
UDC Ventilation
• The net area of the openable doors, skylights
or windows shall be at least 3.5% of the net
floor area of the room.
• Infiltration cannot be considered as make up
air.
• All exhaust shall terminate outside the
building
HUD Ventilation
• At least half of the minimum glazed area shall
be openable directly to the outside for
unobstructed ventilation.
UDC Safety Glazing
• Safety glazing is required in doors by the
Consumer Product Safety Commission.
• Safety glass is required when installed in any of
the following locations:
– In any sidelight or glazing adjacent to a door that
meets all of the following:
• The nearest point of the glazing is within 2 feet of the door.
• The nearest point of the glazing is within 5 feet of the floor.
• The plane of the glazing is within 30 degrees of the plane of
the door when the door is in the closed position.
UDC Glazing Requirements
• In any wall where the glazing is within 5 feet vertically of
the lowest drain inlet and within 3 feet horizontally of the
nearest part of the inner rim of a bathtub, hot tub, shower,
spa or whirlpool appliance.
• Within 4 feet vertically of a tread or landing in a stairway
and within one foot horizontally of the near edge of the
tread or landing.
• Within 4 feet vertically of the floor and 3 feet horizontally
of the nosing of the top or bottom tread of a stair.
• Safety glass is not required where the size of an individual
pane of glass is 8 inches or less in the least dimension
SPS 321.05
UDC Glazing
• Glass blocks are considered to be masonry
products and are regulated under the ACI 530
standard adopted under s. SPS 320.24. They
are not required to be safety glazing.
Ceiling Heights
• Both the HUD Code and UDC have a general
requirement for 7 foot ceiling heights.
• Both allow less than 7 feet for 50 percent of
the floor area but the UDC requires 7 feet in
all habitable rooms, kitchens, hallways,
bathrooms and corridors
• The HUD Code requirement applies to all
habitable rooms and bathrooms. Hallways and
foyers can be 6’ 6”.
Ceiling Height
• The UDC allows beams and girders or other
projections shall not project more than 8
inches below the required ceiling height.
UDC only
• These next slides only refer to SPS 321 or the
UDC Construction Standards.
• The focus is on things that MH installers may
be called on to consider when adding an
addition to a manufactured home or
constructing a garage.
Attics and Crawl Space Access
• An attic or a loft is a space found directly
below the pitched roof of a house. As attics fill
the space between the ceiling of the top floor
of a building and the slanted roof, they are
known for being awkwardly shaped spaces
with exposed rafters and difficult-to-reach
corners. Measurements can be difficult if you
don’t know where to measure.
• Attics with 150 or more square feet of area
and 30 or more inches of clear height
between the top of the ceiling framing and
the bottom of the rafter or top truss chord
framing shall be provided with an access
opening of at least 14 by 24 inches, accessible
from inside the structure.
UDC Attic Access
• Attics with 150 or more square feet of area
and 30 or more inches of clear height
between the top of the ceiling framing and
the bottom of the rafter or top truss chord
framing shall be provided with an access
opening of at least 14 by 24 inches, accessible
from inside the structure.
Measure from top of the framing
To the bottom of the rafter or truss
Crawl Space Access
• UDC - Crawl spaces with 18 inches of clearance or
more between the crawl space floor and the
underside of the house floor joist framing shall be
provided with an access opening of at least 14 by
24 inches.
• HUD - Access opening(s) not less than 18 inches
in width and 24 inches in height and not less than
three square feet (ft.2) in area must be provided
and must be located so that any utility
connections located under the home are
accessible.
UDC Fire Separation
• Fire separation distance is to be measured
perpendicular from wall to wall or property
line, ignoring overhangs.
• Fire separation distances between
manufactured home within a manufactured
community are established shall be provided
in accordance with the distances specified in s.
SPS 326 unless there are other local standards.
UDC Fire Rated Construction
• Is designed to protect the home from external
fire sources.
• Between a dwelling and a detached garage
the fire rated construction may be on either
facing wall. (SPS 321.08)
• However, between 2 dwellings, the fire rated
construction shall be on both facing walls.
Fire Rated Construction
• Fire rated construction for a wall facing a
detached garage is a 3/4th hour wall.
• Fire rated construction for a wall facing
another dwelling is also a 3/4th hour wall.
• Fire rated construction for a window facing a
detached garage is 1/3rd hour.
Fire Rated Construction
• The minimum separation distance between a
dwelling and detached garage is 5 feet.
Fire Rated Construction
• The minimum separation distance 20 feet
does not require fire rated construction.
• Fire separation distance between a dwelling
and the property line of 3 feet or more means
that fire rated construction is not required.
Fire Rated Construction
• Gypsum Board comes in 3 types
– Regular, Type X & Foil Backed
• Fire rated construction requires Type X
• One layer of 5/8-inch Type X gypsum drywall on
the garage side of the separation wall or ceiling is
one example of fire rated construction.
• Two layers of ½-inch gypsum drywall on the
garage side of the separation wall or ceiling is an
example of fire rated construction.
Joints
• Joints must be taped or sealed.
• Joints shall be fitted so that the gap is no more
than 1/20-inch with joints backed by either
solid wood or another layer of drywall such
that the joints are staggered.
Note: 1/20-inch is approximately the thickness of a U.S. dime.
Fire Rated Construction
• The door and frame assembly between the
dwelling unit and an attached garage shall be
labeled by an independent testing agency as
having a minimum fire-resistive rating of 20
minutes.
(Home improvement stores generally sell 20 minute and 90 minute doors.
Often there is no price difference so shop smart.)
• A window can be installed in a fire rated door
only if allowed by the door's listing.
Draft Stopping
• Acceptable draft stopping materials for
concealed roof spaces and attics include:
• A. 3/8-inch wood structural panel
• B. ½ -inch gypsum board
Fire Blocking
Fire blocking must be provided in all of the following
locations:
• In concealed spaces of walls and partitions, including
furred spaces, at the ceiling and floor levels.
• At all interconnections between concealed vertical and
horizontal spaces including the attachment between a
carport and a dwelling.
• At all openings around wires, cables, vents, pipes,
ducts, chimneys and fireplaces at ceiling and floor
level.
• At all openings around wires, cables, vents, pipes,
ducts, chimneys and fireplaces at ceiling and floor
level.
Fire blocking for wires, cables, pipes and vents
only, non-shrinking caulk, putty mortar, or
similar material may be used provided no
dimension of the opening exceeds 1/2 inch
around the penetrating object.
Fireblocking shall consist of one of the following:
(a) 2-inch nominal lumber.
(b) Two layers of one-inch nominal lumber.
(c) One thickness of ¾-inch nominal plywood or
wood structural panel with any joints backed
with the same material.
(d) One thickness of ½-inch gypsum wallboard, face
nailed or face screwed to solid wood, with any
joints backed with the same material.
• For chimneys, fireplaces and metal vents,
fireblocking shall be metal, cement board or
other noncombustible material.
Fiberglass or mineral wool batt insulation may
be used if both of the following conditions are
met:
1. The least dimension of the opening may not
exceed 4 inches.
2. The batt shall be installed to fill the entire
thickness of the opening or stud cavity.
SPS 321.10 Protection against decay and termites
• To protect wood, the wood shall be labeled
and pressure treated with preservative in
accordance with a AWPA standard.
When Preserved Wood Is Used
(a) Resting directly upon or embedded in earth.
(b) Floor joists or sleepers that meet certain conditions.
(c) Floor joists exterior to the dwelling that are within 18 inches above exterior grade,
unless protected with a moisture barrier.
(d) Girders that span directly over and within 12 inches of earth.
(e) Sills and rim joists that rest on concrete or masonry and are also below grade or
within 8 inches above final exterior grade.
(f) Siding and sheathing in contact with concrete, masonry or earth and within 6
inches above final exterior grade.
(g) Ends of wood structural members and their shims resting on or supported in
masonry or concrete walls and having clearances of less than ½ inch on the top, sides
and ends.
(h) Bottom plates or sole plates of walls that rest on concrete or masonry and that are
below exterior grade or less than 8 inches above final exterior grade.
(i) Columns in direct contact with concrete or masonry unless supported by a
structural pedestal or plinth block at least one inch above the floor.
(j) Any structural part of an outdoor deck, including the decking.
(k) Permanent wood foundations.
Floor Joints or Sleepers Require
Preserved Wood
a. Floor joists or sleepers that meet all of the
following conditions:
1. The joists or sleepers are protected from the weather.
2. The joists or sleepers are within 18 inches above a
lower floor surface, deck or soil.
b. Floor joists exterior to the dwelling that are
within 18 inches above exterior grade, unless
protected with a moisture barrier.
c. Girders that span directly over and within 12
inches of earth.
Decay & Termite Resistant Species
Naturally Decay-resistant Species = Heartwood
of redwood, cypress, black walnut, catalpa,
chestnut, sage orange, red mulberry, white oak,
or cedar lumber
Naturally Termite resistant Species = Heartwood
of bald cypress, redwood, and eastern red cedar
MH Home Installation
• The following slides relate to manufactured
home installation standards applicable to
home produced on or after April 1, 2007.
• Use the combined code that is listed as an
additional resource for this course as your
guide.
MH Installation
• Federal Law at 24 CFR 3285 sets out federal
model installation standards. Wisconsin has
adopted these standards with some
modifications. The code uses underlined text
to designate Wisconsin amendments.
MH Topics
•
•
•
•
•
General concepts related to the code
Soil conditions, drainage and grading
Alternative foundation systems
How to read pier load tables
Caps, blocks and shims
General Topics
• A manufacturer must provide two types of
installation instructions:
– At least one method for temporary support when
the home is stored at the plant, a retailer’s lot or
the home site.
– A complete installation manual for permanent
installation of the home.
• A manufacturer's installation manual must
note site conditions that do not allow the use
of the manufacturer's installation instructions.
• An alteration of the home by the installer is
not allowed if it imposes additional loads to
the manufactured home or its foundation
unless the alteration is approved by:
A. Manufacturer's installation instructions
B. By a registered professional engineer or architect
Abbreviations to Know
• ASTM -- American Society for Testing and Materials
• AWPA – American Wood-Preservers’ Association
• DAPIA – Design Approval Primary Inspection Agency – approves
manufacturer designs as meeting the HUD Code
• MHCC – Manufactured Housing Consensus Committee – the code
approval committee
• MHCSS -- Manufactured Home Construction and Safety
Standards (the HUD Code)
• NFPA - National Fire Protection Association
• UL - Underwriters Laboratories
Flood Hazard Maps
• In Wisconsin, the “flood hazard maps” means
the maps adopted by each county. This varies
across the country.
• In Wisconsin’s code, the term “department”
means the Department of Safety &
Professional Services.
What does Flood Hazard Area Mean?
The greater of these two:
a. The special flood hazard area shown on the
flood insurance rate map.
b. The area subject to flooding during the design
flood and shown on a county’s flood hazard
map, or otherwise legally designated.
• Prior to the initial installation of a new
manufactured home, the owner or permit
applicant is responsible to determine whether
the home site lies wholly or partly within a
special flood hazard area as shown on the
county’s flood insurance rate map, flood
boundary and floodway map, or flood hazard
boundary map. If so located, the map and
supporting studies adopted by the county may be
used to determine the flood hazard zone and
base flood elevation at the site.
What is the “Lowest” Floor
• Flood regulations often refer to the “lowest”
floor. In Wisconsin, for a manufactured home
this means: The floor of the lowest enclosed area
of a manufactured home.
• An unfinished or flood-resistant enclosure, used
solely for vehicle parking, home access, or limited
storage, must not be considered the lowest floor,
provided the enclosed area is not constructed so
as to render the home in violation of the floodrelated provisions of this standard.
What is “Level”
• The manufactured home must be adequately
leveled prior to completion of the installation, so
that the home's performance will not be
adversely affected.
• The home will be considered adequately leveled
if there is no more than 1/4 inch difference
between adjacent pier supports (frame or
perimeter) and the exterior doors and windows
of the home do not bind and can be properly
operated.
Installation in a Flood Zone
• Installation of a manufactured home in a flood
hazard area is also subject to FEMA regulations
(FEMA 185).
• Appliance air inlets and exhausts in flood hazard
areas may NOT be located under the floor of the
home. Appliance air inlets and exhausts in flood
hazard areas must be located at or above the
same elevation as the lowest elevation of the
lowest floor of the home.
Soil Classifications for MH Installers
The soil classification and bearing capacity of
the soil must be determined before the
foundation is constructed and anchored.
The code delineates several methods for making
those determinations
Steps for Soil Determinations
(a) Soil tests
(b) Soil records
(c) If the soil class or bearing capacity cannot be determined by test or
soil records, but its type can be identified, the soil classification, allowable
pressures, and torque values shown in Table to §3285.202 may be used.
(d) A pocket penetrometer
(e) In lieu of determining the soil bearing capacity by use of the methods
shown in the table, an allowable pressure of 1,500 psf may be used, unless
the site-specific information requires the use of lower values based on soil
classification and type.
(f) If the soil appears to be composed of peat, organic clays, or uncompacted
fill, or appears to have unusual conditions, a registered professional geologist,
registered professional engineer, or registered architect must determine the
soil classification and maximum allowable soil bearing capacity.
In Communities
Where a community-wide soil test does not
exist and a soil test is required by chapter SPS
321, such as for a proposed frost-freefoundation design, the test shall be conducted
to determine the soils in the entire community
rather than at an individual site.
Then Find Soil Bearing # here
Find soil description here
Soil Table
Torque Test
The torque test probe is a device for measuring
the torque value of soils to assist in evaluating
the holding capacity of the soil in which the
ground anchor is placed. The shaft must be of
suitable length for the full depth of the ground
anchor.
Courtesy of Minuteman Products
Torque Test
The torque value is a measure of the load
resistance provided by the soil when subject to
the turning or twisting force of the probe.
The value is read from
the gauge on the
wrench.
Drainage
Drainage must be provided
to direct surface water away
from the home to protect
against erosion of foundation
supports and to prevent
water build-up under the
home, as shown in Figure to
§3285.203.
• All drainage must be diverted away from the
home and must slope a minimum of one-half
inch per foot away from the foundation for
the first ten feet.
• Other methods, such as a drain tile and
automatic sump pump system, must be
provided to remove any water that may
collect under the home.
• The use of ditches and culverts to drain
surface runoff is subject to local and state
regulations and shall be included and
considered in the overall site preparation.
• Where property lines, walls, slopes, or other
physical conditions prohibit the required
slope, the site must be provided with drains or
swales or otherwise graded to drain water
away from the structure.
Vapor Retarder
• A vapor retarder must be installed to cover the
ground under the home for all homes produced
on or after 4/1/2007.
• A minimum of six mil polyethylene sheeting or its
equivalent must be used.
• The entire area under the home must be covered
with the vapor retarder, except for areas under
open porches, decks, and recessed entries. Joints
in the vapor retarder must be overlapped at least
12 inches.
The vapor retarder may be placed directly
beneath footings, or otherwise installed around
or over footings placed at grade, and around
anchors or other obstructions.
Any voids or tears in the vapor retarder must be
repaired. At least one repair method must be
provided in the manufacturer's installation
instructions.
Alternative Foundation Designs
Alternative foundation systems or designs are permitted in accordance with
either of the following:
(1) Systems or designs must be manufactured and installed in accordance
with their listings by a nationally recognized testing agency, based on a
nationally recognized testing protocol; or
(2) System designs must be prepared by a professional engineer or a
registered architect or tested and certified by a professional engineer or
registered architect in accordance with acceptable engineering practice and
must be manufactured and installed so as not to take the home out of
compliance with the Manufactured Home Construction and Safety Standards
(part 3280 of this chapter).
(3) SPS 321.40 (1) (k) Footings and foundations may be designed in
accordance with subchapters IV and V of chapter SPS 321, which include a
frost depth of at least 48 inches.
Wisconsin Housing Alliance
Frost Free Design
• The Wisconsin Housing Alliance has a
proprietary frost free design that is approved
by the State of Wisconsin. It is not approved
for use in other states.
• It is based on the simple premise that is there
is not water under the home there can be no
frost heave.
• Other companies have similar designs
Place on proper soil, grade as required, install perimeter to manufacturer’s instructions, drain water
way by gutters or drain tile.
The design can be used in the visible soil types shown above or if the poor soil was
replaced per Note #2 in the design documents
Alliance Frost Free Design
• The design documents are included in the
resource materials.
State Approved Slab Design
State Approved Slab
• This slab design was prepared by the
Department as a safe harbor meaning that
local inspectors will accept this design.
• Pay particular attention in this design as well
to the note which set out requirements for its
use.
Limitations:
1. Minimum 3,000 psi Concrete. [HUD 3285.312 (b) (ii)]
2. Rebar and mesh at least grade 40.
3. Soil Bearing capacity at least 2,000 psf [SPS 321.40(2)(b)2. and HUD 3285.312 (b) (ii)]
4. Placed on undisturbed soil. Shall not be placed on unprepared fill material, organic soil,
alluvial soil, mud, or frozen soil. [SPS 321.40(2)(b)1. and HUD 3285.312 (a)]
5. 8 to 10” of clean graded sand, gravel or crushed stone base in clay soils [SPS 321.20(2)
with added thickness to resist frost.] Compaction of sand etc, should 95% of modified
Proctor.
6. 6 mil vapor retarder overlapped 12 inches and sealed. [HUD 3285.204]
7. Maximum pier spacing of 7 feet with max load per pier of 5, 300 lbs. when placed on 6”
thick slab. [SPS 321.40(2)(b)10. and HUD 3285 (e), Table.]
8. Maximum load per pier of 11,900 lbs. at mating line when centered on the 20” W. X
10” D. thickened slab, Section B-B, reinforced with 2 - #4 bars. Individual pier footings at
mating line meeting sizing requirements s.3285 (e), Table may be used in lieu of
continuous thickened slab. [HUD 3285 (e), Table.]
9. Site shall drain away from the home per SPS 321.12. Ensure drainage of sand fill zone
so that any clay does not cause water to pool under the slab.
10. The water table shall not be above the frost penetration depth, i.e. at least 4 feet
below grade. [SPS 321.15(2)(a)]
11. Saw cut joints in slab so that sections are approximately square. (Example: 16’ by 76’
slab = 4 segments.)
Pier Designs & Loads
• The load bearing capacity for each pier must
be designed to include consideration for the
dimensions of the home, the design dead and
live loads, the spacing of the piers, and the
way the piers are used to support the home.
How to Read 3285.303 Table
1. Select the desired pier
spacing
2. Find Roof Load
from Data Plate
3. Read across for maximum
load
Interpolation
Interpolation or creating a midpoint out of other
know values such as pier spacings is permitted.
That means you can create a table for 7 foot
spacing by comparing values for 6 foot spacing
to those for 8 foot spacing.
Example
Know Values from the Table
Interpolated Value
7 ft. 0 in …..|
30
|Frame
………|
4,700 + 6,200/2
=5,450
Table Types
• Table 1 to §3285.303 is Frame Blocking
Only/Perimeter Support Not Required Except
at Openings
• Table 2 to §3285.303 is Frame Plus Perimeter
Blocking/Perimeter Blocking Required
Block Piers
(1) Load-bearing (not decorative) concrete
blocks must have nominal dimensions of at least
8 inches × 8 inches × 16 inches;
(2) The concrete blocks must be stacked with
their hollow cells aligned vertically; and
(3) When piers are constructed of blocks stacked
side-by-side, each layer must be at right angles
to the preceding one.
Blocking
A 4" solid block can be used every place in a stack of pier blocks on the
bottom of the stack
Clearance
• A minimum clearance of 12 inches must be
maintained between the lowest member of
the main frame (I-beam or channel beam) and
the grade under all areas of the home.
• (This is actually more stringent than for preApril 1, 2007 homes. Under the prior
standard, 12 inch clearance was required for
75% of the area under the home.)
Wood Cap
• A wood cap must be No. 2 spruce/pine/fir.
• All lumber used as cap and gap filler shall be
the same species of wood.
• Lumber used to fill a gap in the pier may only
be placed at the top of the pier.
• All caps must be of the same length and width
as the piers on which they rest. (Some mistakenly
read this as only requiring the cap lumber to be the same size,
rather, the wood has to be the same size as the pier below it.)
Wood Caps
• When split caps are used on double-stacked
blocks, the caps must be installed with the
long dimension across the joint in the blocks
below.
Shims
• Nominal 4 inch × 6 inch × 1 inch shims to level
the home and fill any gaps between the base
of the main chassis beam and the top of the
pier cap.
The dimensions are read as width, length and height.
• Shims must be used in pairs, and must be
driven in tightly so that they do not occupy
more than one inch of vertical height
Manufactured Piers
• Manufactured pier heights must be selected
so that the adjustable risers do not extend
more than 2 inches when finally positioned.
Thank You for Your Attention
• Using these slides plus the other resource
materials, please take the exam at this time.