Understanding how manufactured homes are constructed can help you remodel or modify a home. This is especially true when you have to replace the flooring or move walls in a mobile home. Knowing the construction methods that are involved, and the order of construction, can help you plan your project better and save money.
Manufactured Home Construction Basics
Both single wides and double wides (which are basically just two single wides) sit on a steel chassis.
Steel beams with slight curvatures are welded together to create a cambered chassis.
This is done to help even out or distribute the weight of the home. These curves are barely noticeable but are vital to a strong manufactured home that can withstand vibrational forces and transportation at 55 mph.
The camber or curve of the steel chassis helps the home absorb shocks and distribute weight more efficiently.
The best chassis are built with American steel. Cheaper Chinese steel is used in a few builders – try to stay away from those if you have a choice.
The ‘side to side’ beams have outriggers on the ends. Outriggers are the tapered edges that may or may not go to the very edge of the home.
Cheaper manufactured homes will not have outriggers that go to the very edge of the home.
Outriggers that go to the very edge are better because they hold the weight of the walls and the roof better. If the outriggers aren’t strong enough or doesn’t extend out far enough, the home’s perimeter walls and roof can sag.
Besides the chassis and roof-down structural integrity, manufactured homes are built much like site-built homes.
Once the chassis has been built to specifications, the builders will use a jig or template to built the floor joists from 2x6s or sometimes 2x8s for the higher quality homes.
Palm Harbor homes uses computer aided design programs to help design their floor joists for each model.
The heating and cooling vents, plumbing lines, and electrical cables will be installed through the floor joists. In some models, the ductwork and electrical will be ran through the roof trusses.
Next, the subflooring and floor covering will be laid.
How Walls are Built in Manufactured Homes
Walls are built using wood boards called studs. Studs are the vertical boards and are normally 2″ x 4″ and spaced every 16″ in a manufactured home. That’s what the term 16″ OC, or ‘on center’ means in construction lingo. Better quality manufactured homes will have 2×6 studs and more affordable homes will have 2x3s. State laws and wind zones will determine how your manufactured home is constructed.
Interior walls, sometimes called partition walls because they separate space and have no load bearing qualities, can be 2x2s and spaced 24″ apart.
The vertical studs are held together with horizontal boards called bottom plates and top plates. Home Tips shares a helpful illustration of the parts of a wall:
Walls around doors and windows are built differently to distribute weight down the sides of the rough opening. Structural headers are used above the doors and windows to reinforce the area. Oftentimes trimmer or king studs will be used (sometimes both but not as often).
How Walls are Attached to Joists and Trusses
The bottom plate of an interior wall is nailed into the floor joists. The floor and the roof will sandwich the walls to create a structurally sound wall.
The perimeter walls of a manufactured home are attached to the floor joists using nails and 26 gauge metal straps as shown below. These are also called hurricane straps.
The perimeter walls are attached to the roof trusses using metal straps and nails, as shown below.
If your manufactured home’s roof truss sits completely upon a top plate it usually indicates a load bearing wall.
In reality, double wides are just two single wides. Each piece of a double wide has its own integrity and strength but together it creates an even stronger home.
In the image below, you see one half of a double wide that has the interior and perimeter walls installed. Notice there is no roof, yet. Roofs are built separately from the rest of the home and installed after all interior work has been done.
Double Wide Roofs
Double wides use roof trusses that are
Once the roof is installed over the walls it will create a strong web of structural integrity.
Exterior Construction on New Manufactured Homes
Some manufactured home builders do things a little differently. Some brands will put the roof on first and then add the exterior sheathing, others will add the sheathing on before the roof.
Jacobsen Homes does the latter. Jacobsen Homes released a video on Youtube that shows their manufactured home construction process. Of all the videos I’ve watched they seem to call out other brands more often for cutting corners or using cheaper materials – I enjoy that.
Exterior sheathing should be OSB or plywood. There is a product petrochemical product called Thermo-Ply. It’s cheaper and doesn’t seem to withstand the elements as well.
Video Tours and Construction Videos
We have added several of the top manufactured home builder’s construction videos below. This should make it easy for you to see how each company differs. Remember, though, a few of the brands below are owned by the same corporation so there really isn’t much of a difference.
Also, keep in mind that these brands are showing their best models in these videos and therefore their best construction. Most models that builders offer will not have the materials mentioned.
How Manufactured Homes are Constructed at Clayton Homes
How Manufactured Homes are Constructed at Jacobsen Homes
How Manufactured Homes are Constructed at Palm Harbor
How Manufactured Homes are Constructed at Champion Homes
How It’s Made TV Show Covers Factory-Built Homes
How Manufactured Homes are Constructed at Schult Homes
How Manufactured Homes are Constructed at Golden West Homes
A Better Look Inside a Manufactured Home
If you want to visualize a double wide’s building process, this image should help you. I found it at Frey’s Mobile and Manufactured Home Sales website.
1. 2×10 #2 SPF or better floor joists on 16″ centers.
2. Perimeter heat with wall mounted registers and boots.
3. Shaw Acclaim 16 ounce casual texture carpet with 5 pound rebond pad.
4. 2×6 Stud SPF or better placed on 16″ centers.
5. 2×10 headers above all windows and doors.
6. 7/16″ OSB exterior sheathing.
7. R-19 Owens Corning Fiberglass wall batt insulation.
8. R-33 Cellulose Roof Insulation.
9. Optional 7/12 roof pitch with 50 or 70-pound snow load.
10. 2×6 Fascia plate.
11. 7/16″ OSB exterior roof sheathing.
12. Architectural Roof Shingles.
13. Full-finish drywall throughout the home.
14. Dual pane vinyl, single hung – single tilt windows.
15. 36×80 vinyl clad steel insulated 6-panel door with storm front and rear.
Conclusion – How Manufactured Homes are Constructed
Knowing how manufactured homes are constructed is smart for those looking to remodel an older mobile home or buy a new manufactured home.
Over the years, the manufactured home builders have tweaked their building processes down to a fine science and the quality of the homes has increased significantly.
Building a home in a factory is a safer and far more affordable method of home construction.
Advanced computer-aided design, specialized machinery, and tight inventory control has allowed brands to build manufactured homes at half the cost per square foot as a site-built home.
Constructing a home inside a temperature controlled factory with well-trained employees that know they will have a job tomorrow creates a higher quality product. People that work regular shifts is the best all-around method for home construction.
As always, thanks so much for reading Mobile Home Living!
Updated April 13, 2019 (MMHL does not endorse or recommend one manufacturer over another. Each manufacturer has their own strengths and weaknesses.)