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Codes & standards for manufactured homes, mobile homes, doublewides, multiwides, & trailers.
This article assists mobile home, trialer, or doublewide owners and inspectors of those homes who need to find the appicable codes and standards for manufactured homes, multiwides, trailers or mobile homes.
Manufactured homes are those built entirely in a factory. They are then transported to a building site and installed.
A manufactured home is a single-family dwelling built according to the U.S. Department of Housing and Urban Development (HUD) Manufactured Home Construction and Safety Standards Act, which is a national, preemptive building code. - Washington State Government, http://www.lni.wa.gov/TradesLicensing/FAS/Mobile/ (2014)
A mobile home is a factory-built dwelling built prior to June 15, 1976, to standards other than the HUD Code, that were acceptable under applicable state codes in effect at the time of construction or introduction of the home into the state.
Manufactured Homes other countries such as Australia are regulated by different laws that we also provide here.
Manufactured Home Construction and Safety Standards Act, U.S. HUD, Code of Federal Regulations No. 24, PARTS 0-199, 5/1/2001, can be read at http://www.gpo.gov/fdsys/pkg/CFR-2001-title24-vol1/content-detail.html
MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS, PART 3280 contains 10 subparts pertaining to General (data plate and certification contents and locations), Plans (dimensions, exits, etc), Fire Safety, Body and Frame, Testing, Thermal Protection, Heating/Cooling and venting systems, Electrical, and Transportation (axles, springs, drawbar). It's about 90 pages of regulations.
Part 3282 (subset of the document links just above) discusses pre-emption of state laws, among other things, and requires a new unit to be delivered with a "consumer manual" containing required information about the unit. - Thanks to NHFireBear for this update, April 2015. Retrieved 9 April 2015, original source: www.gpo.gov/fdsys/pkg/CFR-2001-title24-vol5/pdf/CFR-2001-title24-vol5-subtitleB.pdf [note this is a very large PDF that contains other sections. Our live link above has excerpted the Manufactured Home standards section from the HUD document - Ed.]
HUD INSPECTION CHECKLIST, Housing Choice Voucher Program [PDF], US Department of Housing & Urban Development, Office of Public and Indian Housing, (2012), retrieved 2017/06/09, original source: https://portal.hud.gov/hudportal/documents/huddoc?id=DOC_11775.pdf
MANUFACTURED HOUSING RULES (TEXAS), [PDF] Effective: November 23, 2014, Administrative Rules of the Texas Department of Housing and Community Affairs 10 Texas Administrative Code, Chapter 80, retrieved 2017/06/09, original source: https://www.tdhca.state.tx.us/mh/docs/Rules-141123-160514.pdf
PERMANENT FOUNDATIONS GUIDE FOR MANUFACTURED HOUSING Chapter 1-5 [PDF], U.S. Department of Housing and Urban Development (1996), source: https://www.huduser.gov/portal/publications/destech/permfound.html This is the complete HUD foundation handbook in PDF format, compressed for faster downloading, no loss of data, no loss of image quality.
Abstract quoted from HUD
This handbook is a guide for those approving HUD-code manufactured homes on permanent foundations, including engineers, manufacturers, and site owners seeking approval. It provides current technical information, recommendations, and tables of analytical data, expanding and clarifying the definition of a permanent foundation. It updates 1989 loading requirements for snow, wind, and seismic forces.
Because of the increased use of multi-section manufactured homes, the guide now includes consideration of large openings along the length of marriage walls in multi-section units.
The construction recommendations assure that the home, foundation, and site are all compatible. In addition to the new technical recommendations, the guide has been expanded and reorganized for easy reference with more illustrations and clarifications. The handbook can greatly assist preparation of the worksheets needed to apply for an FHA mortgage
GUIDE TO FOUNDATION AND SUPPORT SYSTEMS FOR MANUFACTURED HOMES [PDF], (2002, initally marked "Draft not for distribution") Office of Policy Development and Research (PD&R) U.S. Department of Housing and Urban Development, HUD USER P.O. Box 23268, Washington, DC 20026-3268 USA, Tel: 1-800-245-2691 TDD: 1-800-927-7589 and PATH (Partnership for Advancing Technology in Housing), 451 Seventh Street, SW Washington, D.C. 20410 UDA Tel: 202-708-4250 Email: firstname.lastname@example.org, PATH is managed and supported by the U.S. Department of Housing and Urban Development (HUD). Retrieved 2017/06/07, original source: https://www.huduser.gov/portal/Publications/PDF/foundations_guide.pdf
This document discusses factors to consider in manufactured home (& mobile home) foundation design, non-proprietary foundation and support systems, and proprietary foundation and support systems for mobile homes / manufactured homes.
Note: The contents of this report are the view of the contractor and do not necessarily reflect the views or policies of the
U.S. Department of Housing and Urban Development or the US government.
HUD-Manufactured Housing and Standards, U.S. Department of Housing and Urban Development (HUD), Website: http://portal.hud.gov, Retrieved 5/1/2014, original source: http://portal.hud.gov/hudportal/HUD?src=/program_offices/housing/ramh/mhs/faq, Quoting:
A manufactured home (formerly known as a mobile home) is built to the Manufactured Home Construction and Safety Standards (HUD Code) and displays a red certification label on the exterior of each transportable section. Manufactured homes are built in the controlled environment of a manufacturing plant and are transported in one or more sections on a permanent chassis.
Homes built prior to June 15, 1976, even with modifications, do not meet the HUD standards and cannot be accepted as compliant with the HUD Code. As the homeowner, you may find a licensed engineer willing to inspect your home for compliance with your state's housing code.
FHA does not insure mortgages on manufactured homes built prior to June 15, 1976. Most other mortgage insurance firms follow FHA's policy.
However the term "manufactured home" is used by different authoritis to include a variety of construction types as we list next. Manufactured homes include:
Modules are transported to the site and installed. See MODULAR HOME CONSTRUCTION for a detailed look at modern modular home construction.
Panels—a whole wall with windows, doors, wiring and outside siding—are transported to the site and assembled. See Panelized Construction for a detailed look at a 1950's panelized construction home that was war surplus (Fishkill NY).
Building materials are factory-cut to design specifications, transported to the site, and then assembled. Pre-cut homes include kit, dome, and log homes.
LOG HOME GUIDE - provides an example of pre-cut homes, how to inspect, diagnose, and repair problems on log houses; how to identify and determine the age of different types of log homes: traditional log homes, manufactured log homes, slab-sided log homes, and alternative log homes using concrete logs and fiberglass logs.
This is the term used for factory-built homes produced prior to when the HUD Code went into effect.
A mobile home is a factory-built dwelling built prior to June 15, 1976, to standards other than the HUD Code [cited above] that were acceptable under applicable U.S. State Codes (or equivalent in other countries) in effect at the time of construction or introduction of the home into the state. E.g. U.S. Washington State WAC 296-150-M. - Washington State Government, http://www.lni.wa.gov/TradesLicensing/FAS/Mobile/ (2014)
The following is the opinion of the author and has not had a technical review by other industry experts.
Various trailer, mobile home, and modular housing
manufacturers may disagree with some of these views. Corrections and content suggestions are welcome.
Australian Manufactured Home Codes & Standards
"National Construction Code (NCC) 2014 (Hard Copy & Online)" Building Code of Australia, Website: https://services.abcb.gov.au/abcbshop/
The NCC 2014 Hard Copy, Digital & Online contains all volumes for both commercial and residential construction as detailed below. The digital format utilises a Digital Rights Management (DRM) system which requires the use of the ABCB's NCC Viewer* to access the file.
Please note that the DRM allows for the installation of the Digital format onto 2 computers/notebooks. Online archives for the included volumes extending back 5 years from the date of the current edition are also provided as part of this package, noting that the PCA archives only extend back to 2011 when it was introduced.
Other Useful Codes References & Standards for Manufactured Homes & Mobile Homes
Baar, Kenneth K. "The Right To Sell The" Im" Mobile Manufactured Home In Its Rent Controlled Space In The" Im" Mobile Home Park: Valid Regulation Or Unconstitutional Taking?." The Urban Lawyer (1992): 157-221.
Bair, Frederick Haigh. Local regulation of mobile home parks: travel trailer parks, and related facilities. Mobile Homes Research Foundation, 1965.
Bartke, Richard W., and Hilda R. Gage. "Mobile Homes Zoning and Taxation." Cornell L. Rev. 55 (1969): 491.
Brown, James Milton, and Molly A. Sellman. "Manufactured Housing: The Invalidity of the" Mobility" Standard." The Urban Lawyer (1987): 367-399.
Budnick, Edward K., and David B. Klein. Mobile home fire studies: summary and recommendations. National Bureau of Standards, 1979.
Budnick, Edward K. Mobile home living room fire studies: the role of interior finish. Division of Energy, Building Technology and Standards, Office of Policy Development and Research, US Department of Housing and Urban Development, 1978.
This paper aims to make recommendations for the design of nonprofit-based programs for the replacement of older, substandard manufactured housing. It begins with an introduction to manufactured housing and its promise as a source of affordable housing, followed by an overview of the theoretical case for a national effort to replace older, substandard manufactured housing.
The paper elaborates on this effort’s scope by using Census Bureau data to describe the relevant housing stock and its occupants. On the basis of qualitative research, it then describes and analyzes previous and existing efforts to replace manufactured housing.
Finally, the paper concludes by synthesizing its findings into recommendations for the design of manufactured housing replacement programs and future research.
Herndon, Thomas W. "Foundation system for manufactured homes." U.S. Patent 4,738,061, issued April 19, 1988.
Kelly, Eric Damian. "Fair Housing, Good Housing ot Expensive Housing-Are Building Codes Part of the Problem or Part of the Solution." J. Marshall L. Rev. 29 (1995): 349.
Kircher, Charles A., Aladdin A. Nassar, Onder Kustu, and William T. Holmes. "Development of building damage functions for earthquake loss estimation." Earthquake spectra 13, no. 4 (1997): 663-682.
Marshall, Richard D. "Wind Load Provisions of the Manufactured Home Construction and Safety Standards: A Review and Recommendations for Improvement." (1993).
Moore, Marvin M. "Mobile Home and the Law, The." Akron L. Rev. 6 (1973): 1.
Nabinger, Steven, and Andrew Persily. "Impacts of airtightening retrofits on ventilation rates and energy consumption in a manufactured home." Energy and Buildings 43, no. 11 (2011): 3059-3067.
National Fire Protection Association. NFPA 70: National electrical code. NationalFireProtectionAssoc, 2007.
Persily, A. K., J. Crum, S. Nabinger, and M. Lubliner. "Ventilation characterization of a new manufactured house." In Air Filtration and Ventilation Centre Conference and Building Environment and Thermal Envelope Council Conference, Washington, DC. 2003.
Runyan, Carol W., Shrikant I. Bangdiwala, Mary A. Linzer, Jeffrey J. Sacks, and John Butts. "Risk factors for fatal residential fires." New England journal of medicine 327, no. 12 (1992): 859-863.
Simmons, Kevin M., and Daniel Sutter. "Manufactured home building regulations and the February 2, 2007 Florida tornadoes." Natural Hazards 46, no. 3 (2008): 415-425.
Spengler, John D., and Ken Sexton. "Indoor air pollution: a public health perspective." Science 221, no. 4605 (1983): 9-17. [Discusses IAQ in mobile homes & manufactured homes]
Question: building codes for manufactured home steps
What are the florida codes for a Manufactured Home steps. Can they be steal attached or wooded removable - Melissa 7/18/2012
Specific examples of unsafe steps and railings at mobile homes and manufactured homes can be found "
Because there are many trip and fall hazards that maybe present at stairs and railings, see our separate articles
STAIRS, RAILINGS, LANDINGS, RAMPS
and CODES for STAIRS & RAILINGS. In addition to those specifications for safe steps and railings, most states require safe and securely-attached entry and exit stairs at both the primary entry to the home and also to a secondary safety or fire exit pathway from the home.
Some later model manufactured homes are provided with emergency egress windows (push out or pop out) but there should be at least two exit doors at opposite ends of the structure.
Question: Step height from ground level to first built-in step of a 5th Wheel travel trailer
(July 29, 2016) Jimmy said:
When my 5th. wheel is parked and not leveled out by the jacks, the step height is 14.6" from the concrete pad to the top of the first step. I know there are codes for residential, but I was hoping there was something on 5th. wheels.
Reply: make your steps safe, regardless
If your home is being uses as a residence, depending on where you live, residential stair codes would still apply;
Even if "codes don't apply" to your situation, safety applies as does the cost of injury or lawsuit;
Make your stairs safe by providing secure steps with reasaonable riser height - say in the 17.3" each range to make up the steps from the stair landing pad to the step that is attached to your 5th wheel home.
You may need handrails and guardrailings too, depending on the situation and the users of the steps.
(Aug 1, 2016) Jimmy said:
So what I think you are saying is, here s no code for any 5th wheel manufacturer on step rise, right ?
(Aug 1 2016) Mod said:
Not quite, Jimmy
There are certainly manufacturing standards for campers and trailers. But those are not building codes.
See NAICS Code 336214 Travel Trailer and Camper Manufacturing
Excerpt of description from SICCODE
this u.s. industry comprises establishments primarily engaged in one or more of the following:
(1) manufacturing travel trailers and campers designed to attach to motor vehicles
(2) manufacturing pickup coaches (i.e., campers) and caps (i.e., covers) for mounting on pickup trucks; and
(3) manufacturing automobile, utility and light-truck trailers. travel trailers do not have their own motor but are designed to be towed by a motor unit, such as an automobile or a light truck.
I do not know this code and did not find a downloadable copy; I'd be surprised if it addresses stair and handrail safety to the extent that you will find in buildign codes.
Are you working on litigation? It sounds that way.
Do the same building codes regulate the construction of modular homes and caravans, trailers, doublewides, mobile homes?
In order to sort out the question of what are common construction practices and what is usually included or not with a manufactured home, we first need to get a couple of confusing terms straightened out.
You originally posted question about double-wide mobile home construction in our article on modular construction
See MODULAR HOME CONSTRUCTION) .
Double-wides and mobile homes are not built using the same structural materials, codes, standards as modular homes. Details about double-wide homes and mobile homes are discussed separately beginning in the article starting at the top of this page: See
MOBILE HOMES, DOUBLEWIDES, TRAILERS.
So What' the Difference Between a Manufactured Home, Mobile Home, & do the same building codes apply?
Yes and no: some codes contain provisions for manufactured or mobile homes, while in other cases and locations those structures are governed by specific building codes.
A modular home is built using conventional 2x4 or 2x6 wood framing much like a stick built house, but it is constructed in several sections that are then trailered to a building site, set upon a conventional building foundation or slab, and fastened together there. The floor of each section is built strong enough to be placed on a temporary trailer for transport to the building site where the trailer chassis is removed prior to assembly of each section.
Building codes and standards for modulars are essentially the same as for a stick-built residential home. Even when the modular home is built in a different state from which it is to be assembled, the home must comply with state building codes.
Also see MOBILE HOME ELECTRICAL DEFECTS
What building codes regulate mobile homes & doublewide homes?
A double-wide or mobile home or trailer (also called house trailers or "static caravans") is typically built to different building standards than a conventional stick-built house or modular built house. These homes are completely assembled in a factory and trailered to a site where they are parked.
The structure includes a permanently-attached trailer chassis, axle, wheels, trailer hitch that are used to deliver the home and can (in concept) be used to move it later.
Unlike modular homes whose constructions are regulated by state and local building codes, mobile homes, double-wides and trailers, are regulated by the U.S. Department of Housing and Urban Development (HUD), via the Federal National Mfd. Housing Construction and Safety Standards Act of 1974.
This national regulation has allowed many manufacturers to distribute nationwide because they are immune to the jurisdiction of local building authorities. There are, however, windzones adopted by HUD that home builders must follow. Depending on where a mobile home is located, these wind zone regulations can require special anchoring or tie downs to reduce the chances of the home being overturned in a storm.
Based on the description in your posted comment/question and your email, you are describing a double-wide mobile home.
Question: where can I find the HUD Section 184 Red Tag on my Home?
Where would the section 184 Red Tag be located on a 1983-West single wide? - Suzanne
(Apr 16, 2014) Sharon said: how do I find the mobile home manufacturer information?
How can I find the name of the manufacturer and model, and possibly a serial number of a 1971 manufactured home? The title says Make: MALB, Body: HS. The home now has vinyl siding so any label is concealed.
Sharon, in this article at MOBILE / MANUFACTURED HOME LABELS we list some locations where you might find the data tag on your mobile home - that's where the manufacturer should be identified. On a home as old as yours there may be no tag. At that point I'd start asking my neighbors who have similar-aged homes.
Reply: See if your home qualifies under HUD Section 184 financing rules
Section 184 refers to manufactured home financing assistance available in the United States from HUD. A red tag indicating that the home qualifies for financing under Section 184 is installed on homes that are eligible. If the Section 184 red tag is missing, the house is not eligible for Section 184 financing. Only manufactured homes built after June 15, 1976 qualify. The tag is mounted outside on the rear of the unit.
This HUD financing pertains to manufactured homes sometimes referred to as "doublewides". So even though your 1983 single wide is newer than the 1976 cutoff year, it may not qualify as qualifying housing by the HUD rules, and it won't bear the RED TAG you are asking about.
Other HUD Section 184 Indian Home Loan Guarantee Program rules that determine if a home qualifies for 184 financing (and thus will bear a red tag) include: 
The manufactured home bears a red tag certifying that its construction complies with the Federal Manufactured Home Construction & Safety Standards
The home mortgage term is for 30 years or less, covers the unit and its building site or an appropriate site lease document was executed
The home was built after 15 June 1976
One- to four-family principal residences that qualify as standard housing under Section 184 (including units in condominiums, planned unit developments, and manufactured housing that is permanently affixed to the property, but not including cooperatives), fee simple properties located on Indian trust land or land located in an "Indian area"
The home is classified and taxed as "real estate" - this will exclude
homes lacking a suitable skirt and adequate insulation (in freezing climates) to protect the mechanicals
homes that are not new and/or that were moved from another site and homes not mounted on a permanently-attached foundation system with their transportation axles and tongue removed (i.e. the home can't easily be simply towed to another site)
homes located in a 100 year flood plain (including the level of ground below the home or its basement or crawl space
Reader comment: NHFireBear offers manufactured homes regulation citations for the U.S. & for individual states
More about relevant mobile home codes, as we expand our local inspection policies:
Where not preempted by the federal code (i.e., things outside of the manufactured home or in mobile homes manufactured prior o 1976), you might want to consult the NFPA 501 Standard on Manufactured Housing, 2013 edition, and NFPA 501A, Standard for Fire Safety Criteria for Manufactured Home Installations, Sites, and Communities, 2013 edition, are both referenced in NFPA 1 (2015). Of course, not all jurisdictions use NFPA 1, preferring International Fire Code or their own home brew of codes.
Furthermore, for those enacting NFPA 1: "New manufactured housing shall comply with Section 20.11 and NFPA 501, Standard on Manufactured Housing." NFPA 1 (2015) National Fire Code, section 20.11.5: Occupancy Fire Safety; One- and Two-Family Dwellings and Manufactured Housing.
"Manufactured Home Sites. The fire safety requirements for the installation of manufactured homes and manufactured home sites, including accessory buildings, structures, and communities,
shall comply with NFPA 501A, Standard for Fire Safety Criteria for Manufactured Home Installations, Sites, and Communities." Ibid., 27.2.
Where the code says "shall comply" it means everyone has to do it, unless they get a proper waiver from the fire marshal, i.e., show that their alternative provides adequate or equivalent safety as would an installation in strict compliance with the code.
FWIW, NFPA 501 has its own labeling requirement showing certification of compliance with NFPA 501 on a permanent plate mounted on the taillight end of each transportable (mobile) unit, located one foot up from the bottom and one foot in from the "road" side. - NHFireBear is a fire inspector and a frequent contributor to InspectApedia.com - Ed.
This article references "Codes and Standards Act" for manufactured homes at 24 CFR Parts 0-199, 5/1/2001.
This manufactured-home standard contains 10 subparts (listed below) pertaining to General (data plate and certification contents and locations), Plans (dimensions, exits, etc), Fire Safety, Body and Frame, Testing, Thermal Protection, Heating/Cooling and venting systems, Electrical, and Transportation (axles, springs, drawbar).
It's about 90 pages of regulations. Part 3282 discusses pre-emption of state laws, among other things, and requires a new unit to be delivered with a "consumer manual" containing required information about the unit. NH FireBear
Thank you once again NHFireBear. For the convenience of readers I have excerpted the portions of the HUD document pertaining to manufactured housing and have included a live link to the document in the article above.
(Apr 9, 2015) NHFireBear said:
You guys are AWESOME! Thanks for cheerfully accepting my suggestions! I know many readers couldn't care less where the rules came from, but others may be curious about the source materials. I came across these materials while trying to help an owner dealing with an inspection triggered by a "housing assistance" application by a renter.
(August 1 2016) NH FireBear said:
... the article [above] does mention "local building codes" (pertaining to MODULAR home, for some reason not relevant to this article), but leaves questions about what other codes may apply, under a section on questions, such as "what Florida codes apply to manufactured home steps" and "What building codes regulate mobile homes & doublewide homes?"
However, it has recently come to my attention the the ICC's International Residential Code (IRC), which is adopted as part of the building code in many states, includes a specific appendix (E) for "Manufactured Homes Used as Dwellings".
The IRC lays out LOCAL CODE applicability to permits and inspections for "Construction, alteration and repair of any foundation system... building services equipment which is necessary for connecting manufactured homes to water, fuel or power supplies and sewage systems, as well as alterations, additions or repairs to existing manufactured homes..." It also mentions that any "auxiliary structures" associated with a mobile/mfd home installation are covered by "applicable local codes", and not preempted by the federal code on the construction of the dwelling itself.
In other words, the state/county/municipality may have their own codes (e.g., the IRC or local equivalents), which do apply to everything OUTSIDE of the manufactured home (which is pre-empted by federal code), as well as installation and any later modifications.
Similarly, it is quite possible that state/local FIRE CODES (including life-safety codes) will apply to inherently unsafe installations, such as pre-1976 mobile homes that lack adequate escape windows or smoke detectors, among other things, especially under any specific programs requiring fire inspections/compliance.
It's a serious problem that shows up at InspectApedia as some reader questions about code compliance, particularly because there is a high correlation between people who place mobile homes on sites AND people who put up modulars and real ignorance of good construction practices, codes, and standards.
Factory built housing is particularly appealing to that class of builders who are not really builders but rather desk-men (and women) who order homes and get them put-up. Often, perhaps usually, because the builder is relying on the assured-code-compliance of the principal structure, and because they are not themselves educated builders but more they are financial people and order-takers or promoters, there is nobody on-site making sure that other site work and features are correct and safe.
I have seen in modular construction foundation catastrophes, incoming electrical fiascos, incoming water and outgoing sewage snafus, house-to-foundation shape mis-match, and even a house roll-over and another foundation collapse.
Even when the factory insists on sending their own trained site crew to install a home the surrounding work may be incompetent.
Similarly in mobile home set-up, complete failure to install proper support, piers, tie-downs. Mobile homes are in some situations more egregious as the buyers tend to be lower-income with less resources to make things right or even to check that the siting and site infrastructure are safe.
SEPTIC & CESSPOOL SAFETY has an example with my friend Steve Vermilye showing a collapsing DIY concrete block access to an open septic tank at a large mobile home facility for farm workers at a famous and expensive NY Pate production facility that we inspected for the farm workers union and for lawyers.
This was just one of many dangerous situations. Electrical was similar.
In addition to those specifications for safe steps and railings, most states require safe and securely-attached entry and exit stairs at both the primary entry to the home and also to a secondary safety or fire exit pathway from the home.
A professional reference designed to assist surveyors, engineers, architects and contractors in diagnosing existing problems and avoiding them in new buildings. Fully revised and updated, this edition, in new clearer format, covers developments in building defects, and problems such as sick building syndrome.
Well liked for its mixture of theory and practice the new edition will complement Hinks and Cook's student textbook on defects at the practitioner level.
Layers of Roofing Permitted on Mobile Homes or Manufactured Homes
While 2 or even 3 layers of asphalt shingles may be permitted on conventional site-built or "stick built" (and probably modular) homes, manufactured homes - assuming we're using the euphamism for mobile home, doublewide, trailer - may be permitted only one layer of shingles at a time on the roof.
Where does this one-layer of shingles on mobile home roofs originate?
Where this one-layer rule is true and appropriate is probably on older mobile / manufactured homes or even new ones if the home was not framed using framing members of the same dimension and strength as a conventional stick built or modular home (typically 2x6, 2x8 or larger rafter or truss roofs of sufficient strength to carry the weight that can, spread over the roof surface, be a ton or more).
For conventional-framed homes regulated by model codes like the IRC figure that two layers is commonly permitted and in some jurisdictions up to 3 layers of asphalt shingle roofing on those structures.
Most experts we consulted and several insurance companies all insist that only one layer of asphalt roof shingles is permitted on manufactured homes, mobile homes, doublewides, trailers, presuming that those structures were built with original framing not intended for the added weight of additional layers of asphalt shingle roofing that can weigh about 100 lbs / square or an additional ton or more of dead load on the structure.
It's interesting that some HUD and FHA documents imply that up to 3 layers of roofing may be permitted, while not always making clear just which building types are being discussed:
Chapter 9. Building Envelope, at HUD (1985) -
Depending on local codes, a maximum of
three (original and two reroofs or original and one
reroof in heavy snow load areas) roofs may be
installed before tear-off is mandatory.
decision to reroof shall depend on the structural
integrity of the supporting roof structure and the
condition of the existing shingled roof. Substrate
for reroofing shall be firm. If not available,
ventilation shall be provided concurrently with the
reroofing. Ridge and soffit ventilation is
FHA 203K financing:
FHA Single Family Housing Policy Handbook II. Title II Insured Housing Programs Forward Mortgages A. Origination through Post-Closing/Endorsement 8. Products b. 203(k) Consultant -
4. Roof. Describe roof work to be performed, such as: installation of a new built-up 10 roof, with new metal gravel stops; installation of 240 Sealtab asphalt shingles on 11 all roofs with a 3:12 pitch or greater; etc. Roofs that already have two layers of 12 shingles should not be roofed again. Remove the existing shingles, then roof with 13 new shingles. Most estimates must be based on square footage projections.
HUD 4905.1 REV-1 Chapter 2 - GENERAL ACCEPTABILITY CRITERIA is quoted:
2-12 ROOF COVERING must prevent entrance of moisture and provide reasonable future utility, durability and economy of maintenance. When reroofing is needed for a defective roof, already consisting of three layers of shingles, all old shingles must be removed prior to re-roofing. - https://www.hud.gov/offices/adm/hudclips/handbooks/hsgh/4905.1/49051c2HSGH.pdf
HUD HOC Reference Guide, Roofs & Attics - at https://archives.hud.gov/offices/hsg/sfh/ref/sfhp1-24.cfm
C. Re-Roofing: FHA will accept a maximum of 3 layers of existing roofing. If more than 2 layers exist and repair is necessary, then all old roofing must be removed as part of the re-roofing. (4905.1 REV-1, 2-12)
These references, not focused on manufactured housing but published by U.S. agencies HUD & FHA, are perhaps a source of the roof layer confusion we've come across, as those documents refer to HUD appraisals and not specifically to manufactured homes
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Defects and Deterioration in Buildings: A Practical Guide to the Science and Technology of Material Failure, Barry Richardson, Spon Press; 2d Ed (2001), ISBN-10: 041925210X, ISBN-13: 978-0419252108. Quoting: A professional reference designed to assist surveyors, engineers, architects and contractors in diagnosing existing problems and avoiding them in new buildings. Fully revised and updated, this edition, in new clearer format, covers developments in building defects, and problems such as sick building syndrome. Well liked for its mixture of theory and practice the new edition will complement Hinks and Cook's student textbook on defects at the practitioner level.
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TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones