Modular home four sections (C) Daniel FriedmanA Photo Guide to Modular Home Construction Identification & Inspection

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Guide to modular home construction, inspection, troubleshooting, diagnosis, repair: how are modular homes recognized?

How is a modular home built, brought to a homesite, and assembled? What portions of a modular home were not made in a factory? What is the quality of modular homes? What are their features, common defects, problems, solutions.

This series of articles describes the history and characteristics of these different types of factory-built structures. Our page top photo shows a four-section modular home after the set-crew has finished placing the four individual sections of the building and the roof has been lifted and enclosed.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Characteristics of Modular Homes or Modular Housing

Modular home during highway transport (C) Daniel Friedman

A modular home is constructed in a factory of one or more sections which are carried to the building site on a trailer (photo above) and lifted by a crane to be set upon a foundation which has been prepared ahead of time (photo below). Modular homes can be quite large, involving four or quite a few more individual sections which are lifted and "set" into place at the site.

Modular homes, earlier in their conception, enjoyed a less than stellar reputation several decades ago, having the reputation of flimsy construction. That is certainly no longer the case.

Definitions: If you are not sure if your home is a mobile home, trailer, double-wide, caravan, or a modular or panelized-built or factory built home, please
see DEFINITIONS of Mobile Home, Doublewide, Modular, Panelized Construction

Article Contents

Contemporary modular construction of homes have these attributes:

Modular home during set process (C) Daniel FriedmanSome manufacturers provide custom architectural services and can deliver unique, but factory-built homes in sections. Contemporary modular construction of homes have these attributes:

How to Identify a Modular or factory built home after construction has been completed

A modular home can be difficult to recognize once its construction has been completed. However these clues will work every time:

Modular home main girder (C) Daniel Friedman Modular home main girder (C) Daniel Friedman

Modular home label (C) Daniel Friedman Modular home label (C) Daniel Friedman Modular roof hinged truss or rafter (C) Daniel Friedman Modular roof hinged truss or rafter (C) Daniel Friedman

Hinged modular home roof (C) Daniel Friedman

Modular home ridge (C) Daniel Friedman

Just how Strong are Factory Built Homes? Stronger than Stick Built Wood Framed Houses?

One modular home I inspected had fallen off of its trailer while being lifted by the crane. It rolled over on its face. Like the unit which had impaled itself on the guard rail, there was little damage other than broken windows.

But there was a slight crease in all of the roof shingles about 24" up from the eaves.

The rafter hinges had all been slightly bent when the section toppled. Outside, even on a modular section which has not fallen, you may see this telltale line of slight shingle anomaly, parallel to the eaves.

Factory built homes are constructed so that each section can withstand being lifted onto a trailer, driven up the highway at 65 mph, pushed or pulled over an uneven, often sloped site, lifted into the air by the site crane, and set into place on the foundation.

Often factory built homes combine glue as well as conventional framing fasteners, extensive use of truss joists, girders, and additional framing of individual building sections so that each can be manipulated into place.

Modular Office Building Labeling & Code Compliance Certification

Modular office building code approval labels (C) InspectApedia RS Modular office building code approval labels (C) InspectApedia RS

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Reader question: how do I establish that my modular office meets my local state building code?

I bought a 12'x56' modular office building from a government auction in sc and got it hauled to my business in NC. But to my surprise I was told by the city code inspector, since the modular was built in the state of SC and has codes and approval of that state I won't be allowed to get the permits until it is certified to the NC building codes. Please suggest what are my options and how can I take care of this issue.

This modular office building was built in 1998 by AAA modular based in SC or GA at the time, unfortunately seems like they are not in business anymore, it has sc stamps etc, let me take some photographs and send them over. - Anonymous by private email 2016/07/23

Reply: how to find and check the labels affixed to the structure, check with the labeling agency

Modular office building labeling in electrical panel (C) RS

Virtually every modular building construction company in North America builds their products to meet all of the state codes where they can imagine their building will end-up. Take a look at the data tags on your building. Send me some sharp photos of the data tag and a couple of the whole building and I can comment further. [Done, shown here - Ed. ]

Check for one or more industry / agency / manufacturing certifying labels that for any modular home or office will identify at least:

Depending on the age and type of modular structure, the identifying labels are usually found in or at the main electrical panel, under the main or kitchen sink affixed to a cabinet door, and/or on a weatherproof data tag riveted to one end of the structure near ground level and near a corner.

Labeling in a modular office building (C) InspectApedia RS

Then give a call to the manufacturer of your building if they are still in business. Give them the same data tag information: model number, serial number, etc. and ask them what codes their product meets.

Labeling in a modular office building (C) InspectApedia RS

When the manufacturer of your modular structure has disappeared, don't give up: you may still be able to obtain documentation of the building codes with which your building complies by contacting the original certifying agency.

Radco who certified your modular building is still in business even though the original manufacturer, Triple A Modular Buildings, Inc., has disappeared: see this ASTM citation for Radco

Labeling in a modular office building (C) InspectApedia RS

and now check with the Radco company. They're based in California, but Radco has an office in your state:

More about mobile home, modular home, manufactured home and modular office labels is at MOBILE / MANUFACTURED HOME LABELS

Modifying Modular-Built Building Construction

Reader Question: is it OK to modify or remove modular home attic ceiling framing?

Can the protruding mating joints on the attic floor of modular home be safely trimmed down? Would like to level flooring for finishing of attic. - Anonymous, 22 July 2015


I cannot say for sure if what you want to trim is safe or not - it depends on the amount. Trimming off 1/4" or even 1/2" of the upper surface of mating 2x lumber of the mating beam in the center of an attic is likely of no import.

For a greater difference or maybe even in all cases as it's easier and faster, I'd consider instead using some shims to level the surface before installing flooring. Use tapered wood shims (available at any building supplier) or left-over tapered wood siding if that's available.

Reader follow-up:

Raised header in attic floor of a modular home (C) InspectApedia Thank you for response. I'm not sure I described the issue properly. I have a setup similar to the image here:
[Photo shown at left]

[Click to enlarge any image]

The existing flooring is significantly lower than the bulky joint in the middle.



Your photo is a very different case from what I was describing. It appears to me that there is a raised header installed where that 2x lumber projects up into the attic.

If so it's probably spanning an open doorway or opening in a wall partition below.

If that is the case you definitely cannot remove or chop down that beam. Your options are to box it in and leave it alone or to hire a structural engineer to re-design a dropped beam in that location. I recommend the former.


Continue reading at PANELIZED CONSTRUCTION or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see KIT HOMES, Aladdin, Sears, Wards, Others



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