Modular Homes -- how far apart can the sections be?

Inspected a modular home recently. The various sections at the base (on the foundation wall) are not in contact. There was 2.5 to 3 inches between the sections. How far apart is too far apart. Any help is appreciated.

Everything I’ve seen tells me the sections should be bolted secure and tightly. Try these links:

Guidelines apply to modular homes as well.

The sections can be miles and sometimes hundreds of miles apart from each other. :slight_smile: Once attached at their final site however, they should be tight as Jimminy said. 2 to 3 apart is unacceptable for a manufactured home.

Viewed from the crawl they should be this tight on a properly married line.

5606 Elliot Estates First 012.jpg

5606 Elliot Estates First 013.jpg

I think you made a typo… Modular Home, not Manufactured. They are two different things.

  • Modular is built in a factory to local building codes.

  • Manufactured is in simple terms a trailer without the axles. It is not built to local building codes.

  • Here in Michigan Realtors can not sell them. They sell the property they sit on and in the purchase agreement the trailer stays with the property. They would have to have a dealers license to sell the Manufactured Home.

*]Mobile Home is a trailer that has axles but, normally has the wheels removed when placed on site.

Any Photo’s???

I’ll post photos later. My photos look similar to Mr. Gault’s 1st photo, but the framing isn’t damaged.

A local manufacturer of modular homes says the bolting should be tight. Common sense says so, too. Now that this has come up, it has got me curious. There doesn’t seem to be a whole lot of guideline information out there on this particular subject. Anybody got a good link?

Modular homes are engineered products and need to be installed according to the manufacturer’s engineering designs and assembly instructions.

Without having the specific engineering and installation instructions for the specific unit, it is impossible to tell whether or not the installation was done correctly or incorrectly.

No general rules apply to modular homes any more than they do to I joists. Each in manufacturer specific based on the manifacturer’s engineering and designs.

Modulars are also NOT built to local building codes.

That is not to say some national code guidelines are used in their construction.

But that should not be confused that modulars can be inspected using local code references. They cannot.

Modulars can only be properly inspected by having the original manufacturer’s installation instruction in hand.

I don’t think you have your information correct. Or, I am not reading your statement correctly! :neutral:

All Modular Homes are built to meet all BOCA (read below) and State Building Codes. Their plans have to be approved by the state before they can be placed on a foundation. In addition they do have to have a C of O to move into them. That is they do have to get their final OK from a local code official in order for someone to move in to them.

There are some special parts involved with Modular Homes when it comes to the Marrage Walls & the Roof Joists but, other then that the rest of the structure is much the same as any other framed house.

It is correct that they may not meet a local community codes or ordnances though.

Most Modular Homes have 2x6 exterior walls, 2x4 interior walls & 2x3 marrage walls (2x3 wall connected to 2x3 wall to make a 2x6 wall.) They also incorporate hinged roof brackets & special Electrical wiring plugs instead of junction boxes to connect the Electrical from one Box (module) to another Box (module). (Normally seen in the basement of craw space at the marrage wall.)

Porches, garages and staircases are normally built on site, Not in the factory and shipped.

Once completed, most people can not tell the difference between a modular & a traditional framed home and that is because modular homes are framed homes. :slight_smile:


All due respect but I don’t think you have your information correct.

Modular manufacturers use portions of national codes to regulate their own industry, but modular homes are not built under the International Residential Code.

In my State, Pennsylvania, for example, modular homes are not regulated nor inspected by State residential building code inspectors at all…(with the exception of foundations, sewer, water service pipes, and service connections)

Instead, modular have their own inspectors which train under a completely different state agency than the one that regulates 1&2 family dwellings a townhouses. Modulars must be installed by specially certified state modular home installers and be inspected by specially trained and certfied Modular Home Inspectors.

In fact, Building Code Officials in Pennsylvania cannot issue Certificates of Occupancy for Modular Homes unless and until we have received a Certificate of Inspection and Compliance from certified installers and certified modular inspectors.

Different states may have different laws regarding ‘modular’ homes, but at least in my state, modular homes are as different from stick-built homes as are LVLs from sawn lumber headers.

There are many similarties between modulars and stick-built dwellings, but modular homes remain engineered products, regulated by the manufacturer and not the ICC Codes.


That is not to say there are not close similarities between modular homes and stick built homes. There are.

But modular homes installations are engineered installations, and without knowing what engineering was used in the original installation, one simply cannot know whether the install complies or not.

In the state of Michigan all Modular Home Plans have to comply with BOCA Code and their plans have to be approved by the state. A Manufactured Home is a different animal here. A Realtor can Not even sell a Manufactured home here. They can sell the property that the Manufactured Home sits on and in the purchase agreement require that the manufactured Home stays on the property. Realtors are not able to sell vehicles, manufactured homes are handled by the MDOT (Michigan Department of Transportation). They would need a dealers license to sell a trailer (manufactured home). Modular Homes in Michigan have to obied by BOCA (ICC) Code.

What you have said about them having to be installed by specially certified state modular home installers is correct. And that person has to follow the the plans & installation plan provided to the state prior to the state approval of the construction.

I agree all states I’m sure are different. What I do know is that here, Modular Homes are not Manufactured Homes. Manufactured Homes are almost the same as a mobile Home (the difference being the date of when they were built & whether or not the axles are left on the structure, for the most part).

I’m sure that I could be wrong but, I would think that if I owned a factory built home company that I would have them all built to the requirements of the strictest state that I plan to sell my product to. That would make construction quick & easy. Changing the construction standards for each home built would be differcult for the crews to keep up with.

I am dealing with all of this right now with my mothers home. We have created our own design. We then have to have the design sent to the Modular Home Building Co. for them to price out the cost and for them to design their building plans. They then have to get their construction plans approved in Lansing before they are able to start construction. The state can and will deny approval of the plan. The state may want something simple like larger windows. The plans will need to be re-done and resubmitted. Like I said I am going through this process here now.


Since mid-1976, all manufactured homes have been constructed to meet the federal building standards adopted and administered by the U.S. Department of Housing and Urban Development. This national code is called the National Manufactured Home Construction and Safety Standards. The code regulates manufactured home design and construction, strength and durability, fire resistance, and energy efficiency. It also prescribes the performance standards for the heating, plumbing, air conditioning, thermal, and electrical systems. The National Manufactured Housing Construction and Safety Standards Act also requires that you receive a home owner’s manual when you buy your home. This manual will explain, among other things, what to do if something goes wrong with your home. Some of the important subjects covered in the home owner’s manual include general maintenance, safety (including a fire safety checklist), and state agencies involved in enforcing the federal manufactured home standards.

**[size=2]State of Michigan **[/size]
Mobile Home Titles,1607,7-127-1585-26228–,00.html

Mobile homes are titled in Michigan. Up until 1978, mobile homes were titled as a “trailer coach”. Since 1978, they are titled as mobile homes. The title is identified as a “Certificate of Manufactured Home Ownership” or “Certificate of Mobile Home Title”. These documents look like a vehicle title and serve the same purpose.

When a person buys a mobile home from a dealer, the dealer applies for the purchaser’s new mobile home title using the Retailer Application for Certificate of Manufactured Home Ownership. When an owner sells their mobile home, they assign the title to the new owner. The new owner brings the assigned title to a Secretary of State Branch Office to have it transferred into their name. An S-110L Application for Certificate of Manufactured Home Ownership is processed at the branch office.

If your mobile home title is lost, you may replace it by processing a duplicate title application at a Secretary of State branch office. All owners shown on the title record must sign the title application and present identification. If an owner cannot appear, they may complete and sign an Appointment of Agent form designating another individual to sign on their behalf.

Your duplicate title will arrive in the mail in 7-10 working days. The fee for a replacement mobile home title is $15.00. Same-day title service is not available.

Related Documents
> [Appointment of Agent for a Vehicle, Watercraft, or Mobile Home](
> [DLEG BCC Retailer Application for Certificate of Manufactured Home Ownership - 116596 bytes](

Modular Homes Manufacturer, Dealer or Builder,1607,7-180-24786_24819-81421–,00.html

Required State License(s):
Modular home manufacturer should submit plans for modular homes to the Department of Labor & Economic Growth, Bureau of Construction Codes for approval prior to manufacturing. Contact the Bureau of Construction Codes at (517) 241-9328. Units should also be inspected.
Builders should have a Residential Builders License from the Builders Board, Department of Labor & Economic Growth, Residential Builders Board at (517) 241-9254.
Modular Home Dealers will need a Residential Builder Salesperson license under one licensed residential builder with the Residential Builders Board.
A sales tax license is also required. You may call the Michigan Department of Treasury at (517) 636-4660.

HUD says how a Manufactured Home is built not who regulates them. In Michigan it is the Secretary of States Office that regulates Manufactured Homes. You know, where you go to renew your drivers license and your vehicle license plates, sorry not MDOT.

My point is here in Michigan, a Modular home is built to traditional building standards and Manufactured Homes are not.

Manufactured Homes are “Titled” like a car or trailer.
Modular Homes receive a “Deed” like any other framed (stick built) home.

I have just checked the State of PA to find out their regulations.

In doing so I found out some interesting information.

I never said the IRC, I said BOCA which is currently part of the ICC.

This is not correct.

From the PA dept. of Community & Economic Development website.

Modular homes are built to comply with the model building codes and are exempt from the PA UCC. Building officials make important contributions to the effective administration of the program. In addition to their oversight in terms of site preparation, foundation construction and utility connections, building code officials shall assist the Department by conducting site inspections of modular housing and components, prior to installation for apparent damage occurring during transportation and other apparent nonconformity. For additional information, please review the complete industrialized housing regulations (PDF).

They are also inspected by the local code inspector to varify that the regulations in the above PDF are followed.

§ 145.83. Issuance of certificates of occupancy.

The local enforcement agency may not withhold the issuance of a certificate of occupancy or other similar permit for certified industrialized housing or a housing structure in which has been installed certified housing components if the industrialized housing or housing structure was constructed and installed on the site under a validly issued building permit and in other respects complies with applicable locally-enacted 28 codes and ordinances not preempted by the act and this chapter.

The provisions of this § 145.83 adopted July 12, 1974, effective July 13, 1974, 4 Pa.B. 1403.

Not correct in regards to your state, PA.

They must follow the ICC as your state (PA) requires.

For additional information, please review the complete industrialized housing regulations (PDF).

I Abriviated the section below… (I did not paste all of the section, see link above.)

§ 145.41. Adoption of standards.
(a) The following codes, which relate to the design, materials and method of construction of buildings, are adopted as the standards applicable to the industrialized housing and housing components for purposes of this chapter:
(1) The ICC International Building Code, with the following exceptions:
(i) The specific article on energy conservation.
(ii) A manufacturer may elect to utilize the 1993 BOCA National Building Code, section 1014.6, exception # 8, with regard to stair geometry (rise & run).
(2) The ICC International Mechanical Code.
(3) The ICC International Plumbing Code.
(4) The National Electrical Code (NFPA No. 70).

They have to be built to meet the current ICC codes.

The information was gathered from:

Again, I must point out that Manufactured Homes are not the same as Modular (Mobile, Trailers) Homes.

Anyone have any comments?
Did I mis-state anything?

Excellent reply and no, I don’t think you missed a thing.
The miss-conception a lot of people have between manufactured and modular homes is unbelievable. As you so stated and if I may add to it: a manufactured home (otherwise known as a trailer or mobile home) is one that has a metal frame, is transported on it’s own wheels and has a hitch. When it’s placed on the foundation the wheels and hitch are removed and both halves (if it’s a double wide) are craned onto the foundation. Cement blocks are used as supports under the frame.
Modular homes are built just like any stick-built home however the biggest difference is they are built in a controlled environment vs. out in the field. They have wooden floor joists, a main carrying beam, lally collumns for support and travel to the site on a flatbed truck. They must be constructed in accordance with state building codes. For instance: the subdivision we built in Massachusetts had to be built in accordance to the Mass State Building Codes and HUD. The company constructing the units was located in NH. The plans had to be stamped & certified before the building official would issue a building permit. The unit also had to bear the seal of certification (in a visible place) usually in the kitchen sink cabinet. Homes built for our NH subdivision had to be built in accordance to local & state codes for example: NH requires all homes (stick built or modular but not manufactured) built using 2 x 6’s for all exterior walls (part of their energy code).
Once plans are stamped by the modular company, their taking on the responsibitiy of the structure. However, in both states I’ve had the building offical come out for their regular inspections ie: foundation, plumbing, electrical - rough and finish. For the structure they only had to do a final inspection.

Thank You Alan,

You just confirmed what I had said for another two states.

Maybe, once I have some time, I or NACHI should work on a couple of mini courses on each of the two.

I should work on creating a training course for the chapters.

Busy right now with the up-comming GLE Chapter Event right now though.


James has no clue and just don’t get it for Pennsylvania.

First, the “BOCA CODES” are obsolete and have have not existed since 1999.
BOCA Codes are not a "part "of the ICC Codes…the ICC Codes completely REPLACED the BOCA CODES over 8 years ago,

Second, ‘stick built homes’ in Pennsylvania are only regulated by the Pennsylvania Uniform Construction Code. This Code DOES NOT INCLUDE ‘manufactured homes’ or ‘modular homes’.

The PA UCC is regulated by the PA Department of Labor and Industry. The ICC Codes are enforced via the certifications issued by the PA Department of Labor and Industry.

Modular Homes are “industrialized housing” in Pennsylvania…regulated by the Department of Community and Economic Development, and ‘inspected’ by those trained directly by the DCED outside of the building ‘codes’.

So you better retract your nonsense and false staements about what think you though you erroneously know about Pennsylvania stick and modular built homes.

That knowledge is all wet and has no basis in the truth.

Stick with what you “think” is true in Michigan.

Your misrepresentations about Pennsylvania conditions only belie your ignorance.



Are you responding to what I posted or to what James posted?

(Who is James?)

If you read what I posted, I said BOCA is a part of the ICC… BOCA, ICBU, and SBCCI merged beginning January 2003 to form ICC, Not in 1999. (info from “Code Check Building”)

I thought we all knew that. Even though we know that some writtings have not been updated, so I have posted what is in those writtings. I even pointed this out in post #15.

Is it just me or does this quote not make sense? :eek:
DCED = Modular
Modular = ICC

DCED = Modular = ICC = PA DL&I = PA UCC
OK, based on the quote of you, I get it now, the PA DL&I when approving the design of a modular home must use the ICC instead of the PA UCC because the DCED requires it that way.

For some reason that just does not sound correct. :frowning:

Please, show me where I posted anything that was a False Statement!

I quoted & even posted the links to verify my statements from the State of PA web site. If I posted anything wrong, then your own state must be wrong also… I’m sorry, how can your state be wrong, they are the ones that created the regulations. So who does that make wrong? :roll:

Are you aware that you are questioning the knowledge of a NACHI CMI?.. :roll: :roll: the most elite of all nacho members, not to mention this title is reserved only for inspectors that claim they met all the rigid CMI non-verified requirements and have an additional 375.00 to send nick.:roll: