What’s supporting your mobile home? It might surprise you to learn that there are many different standard foundations for manufactured homes. They affect everything from how the weather impacts your home to which financing options you can qualify for.
The following are examples of common foundations for various single wides, double wides, and modular homes. There are several types of foundations, including but not limited to...
- Crawl Space
- Piers
- Runners
- Cement Slab
- Basem*nt
Almost all of these include a contractor coming to pour cement. Piers on the other hand, are plastic pads that support the home along the frame. It is very rare to put a mobile home on a basem*nt, as this is much easier with a purpose built modular home.
Here is a video of one of our modular homes being set with a crane on a half basem*nt.
Manufactured Home Foundations
Your foundation is essential to the proper balance and longevity of your mobile home. A well built foundation can prevent moisture build up, flex in the home, and sagging.
Costs for a foundation have quite a range, so to ensure you're getting the best possible price quoted from your contractor. The most affordable option for a foundation is piers, with slabs / runner coming in second.
If you need help organizing the construction of your foundation, consider having us manager your project on your behalf. We handle everything for you, and can save you thousands since we are well versed in the going cost of these jobs.
One more thing, make sure the foundation is built to the actual dimensions (box size) of your home, not the size including the hitch! Believe it or not, we have had customers make this mistake when managing their own project.
Home supports will be placed with spacing as laid out on the foundation print - usually around 8 - 10ft apart along the length of each of the 4 beams. The exact spacing can be calculated (if the soil loading capacity is known) from the installation tables in the manuals on our website (see under Info tab) if there is not a layout supplied from the factory. 
Crawl Space Cross Section
Modular Home Foundation
Block Plan Example
Modular Installation Manual
Manufactured Home Installation Manual: TYPICAL
Pier Plan Example
Double Wide Join Instructions Example
Mobile Home Basem*nt Frame Example
Modular Anchoring Example
Basem*nt Perimeter Frame
Example of Beam Over Basem*nt
The actual supports pillars are usually built with a double stack of regular (webbed) concrete masonry blocks 8" x 8" x 16" stacked with each other layer placed at 90 degrees to the last one for a better stack. If they are over 5' high they should be mortared, otherwise they are 'dry stacked'. On top of the block stack there will be a cap board which is a piece of rough-sawn 1" hardwood about 8" x 16" upon which the steel beam of the home will sit. Once the home is placed onto the foundation the installers will drive some hardwood shims between the cap board and the frame as necessary to further level the home.
The other method is to use regular basem*nt jack posts - they cost a bit more - about $25 each at any builder supply - and have a screw adjustment for exact height. They can be 3', 5' or 8' posts.
How Much Does a Mobile Home Foundation Cost?
You can generally figure about $3,000 per section to install an average home onto your foundation – either onto a concrete slab or a crawl space. Hence a Single Wide will cost around $3,000 and a Double Wide around $7,000 – $12,000 depending on the size. There will be an additional cost to install a home over a full basem*nt, and there are usually regional differences in installation costs.A typical installation involves moving the home onto your foundation and anchoring it down. A Double wide will be bolted together, anchored to your foundation and the ridge cap installed on the roof where the two sections come together. The home installer may also include in their scope of work the installation of the siding on each end of the home, and the inside trim work to finish out the marriage wall, as well as the hook up of the utilities to the homes (water, sewer, gas line and electric hook-up). If the home installer does not include this in their bid, you will need to get additional contractors for this phase of the installation.
We can assist you to obtain contractors for every phase of this work for a small fee, or you may prefer to oversee the work yourself.
Mobile Home Foundations: HUD Requirements
The FHA maintains guidelines and standards when it comes to certifying mobile homes. Specifically, they look at the home’s foundation and the requirements to permanently affix it to the manufactured home. When installing a mobile home foundation, it’s important to follow these guidelines closely no matter which type you choose. Certifying your home and its foundation will help you get a mortgage, loan, or refinance your home with a lender. As long as you use contractors with good reputations, you shouldn’t have to worry much about meeting these requirements. Here are some essential aspects regarding FHA regulations:
The foundation piers of a manufactured home have to have poured, reinforced concrete footings below the frost line.
The wheels, tongue, and axles must be removed.
The mobile home’s skirting must cover the space between the foundation and the house, and it should:
Keep out water and vermin.
Have an access opening.
Be self-supported.
Now, let’s take a look at the most common types of foundations, their costs, and their pros and cons.
Permanent Foundations vs. Non-Permanent Foundations
Permanent foundations, like basem*nts and crawl spaces, cannot ever get removed to place somewhere else. Permanent foundations, well, allow a manufactured homeowner to affix their home to its foundation permanently. You typically need a permanent foundation to meet specific requirements for your home to get seen as “real property,” making it much easier to get financing, especially for FHA loans. Your financing qualifications depend on a combination of factors, like your home’s foundation and the land it’s placed on. Permanent foundations have specific requirements, and some of them are area-specific. They require more time and materials, leading to permanent foundations being the most costly option. If you don’t plan on moving your home anytime soon, or you own the land it’s on, permanent foundations are usually the way to go.
Even though permanent mobile home foundations are more expensive, they come with benefits like:
A better chance to get financing.
Higher resale values if you decide to sell your home.
A lower depreciation rate than non-permanent foundations.
Better protection and support against the elements.
Non-permanent foundations have one significant advantage: you can easily detach them from your home, meaning that you can move them with ease. For these foundations, your mobile home’s wheels, hinges, and axles don’t get removed. The downside to non-permanent foundations is that it’s almost impossible to get real estate loans and financing for the home.
Related: Moving a Mobile Home
Foundations: Types and Costs
There are generally three different foundation types – PIERS in the ground that support the home, a CRAWL SPACE (built with either blocks or poured concrete) or a full BAsem*nT. The price for each of these will depend on the size of your home, and will vary from contractor to contractor.
Pier Foundation
The least expensive foundation is the piers in the ground. This is where 18 inch wide holes are dug into the ground down to the frost depth for the region (usually between 30 and 42 inches deep in the Midwest) and filled with concrete where they are level with the finished grade. The holes are usually about 8 feet apart down the length of the home, along each of the beams under the home. (There are two beams per home section). The home will be installed over the piers and supported by concrete blocks from the top of the piers to the beams. Skirting (or ‘underpinning’) will then be installed around the perimeter of the home from the bottom of the home to the ground. The price for a pier foundation system can be as little as $1,000 for a Single-wide and $2,000 for a small Double-wide.
Pier foundations are an affordable mobile home foundation option.
These foundations take less time than most to install.
Pier foundations are wind-resistant, and you can use them in flood hazard, seismic, and frost-prone areas.
Crawl Spaces
A crawl space is the preferred foundation for most Double-wides. This is an excavated area under a home with either blocks or a poured concrete perimeter wall extending down to a footer poured at the frost depth for the region (usually between 30 to 42 inches in the Midwest). The crawl space will usually extend about 8 – 10 inches above the ground. The home is then rolled over the crawl space on a large beam and roller system, and lowered down and bolted to the foundation around the perimeter. The beams under the home will be supported in the center of the crawl space on blocks extending down to the bottom of the space. The cost for a crawl space may be as little as $6,000 for a small Double-wide, and as much as $15,000 for a large one. A poured concrete foundation will always cost more than a block foundation.
Crawl space foundations are the middle ground when it comes to price ranges.
Installing a crawl space foundation takes less time than a full basem*nt but more time than other foundations.
While crawl space foundations provide some wind resistance, they are not intended for areas prone to hurricanes.
Crawl space foundations are seismic resistant but not flood-resistant.
You can use a crawl space foundation in most climates.
Slab Foundations
A slab foundation consists of a single slab of concrete that is poured underneath a manufactured home. The home will then rest on the slab (with the use of piers) -- slab foundations do not need to be measured as precisely as basem*nt or pit foundations. Typically, the slab will be slightly larger than the home, and mobile home skirting gets used to cover the area between the slab and the house. Uninsulated slabs don’t properly protect your home from the freezing and thawing of the ground underneath it.
Slab foundations are one of the most affordable foundation options for manufactured homes.
Slab foundations are typically quick to construct.
You can use slab foundations in seismic areas.
You can use slab foundations in flood hazard areas.
Slab foundations are not ideal for sloping lots.
If you insulate the slab foundation, you can use it in areas with heavy frost.
Runner Foundations
Runner foundations are unique -- they are made of thin stretches on concrete, running either side to side or containing a “backbone” in the middle that has additional runners extending from it. The exact layout varies since it has to match up to the I-beams that support the manufactured home. Runner foundations are an inexpensive option for mobile home foundations, but they require a more precise layout than slab foundations. These foundations aren’t as popular as other options because the thin and long concrete runners can crack, bend, and move more easily than slab foundations.
Runner foundations are one of the cheapest types of mobile home foundations.
They take more design and construction time than slab foundations.
These foundations resist frost better than slab foundations.
Runner foundations are more prone to damage than other ones.
Basem*nt Foundations
A basem*nt can also be installed under almost any Double-wide. If a home is designed with a basem*nt-ready frame from the factory, then it will be rolled over the basem*nt and supported by the perimeter walls and on poles at the marriage wall. There will already be a section of the floor open for a stairwell. If the home does not have a basem*nt ready frame it can still be installed over a basem*nt, however your contractor will have to make provision for a stairwell, and for additional supports under the home. The easiest way to add a stairwell is to add an enclosed porch to the front or back of the home and build steps inside the porch. A basem*nt will generally cost about $12,000 for a small home, and as much as $25,000 for a large home, with regional differences.
Basem*nt foundations are one of the most expensive foundation options for manufactured homes due to the materials and time used to construct them.
Basem*nt foundations take much longer to design and install than other options.
You can use basem*nt foundations in seismic areas but not in flood hazard ones.
They resist frost relatively well.
Basem*nt foundations provide extra living space.
Basem*nt foundations effectively resist wind loads.
Mobile Home Foundations: The Bottom Line
Choosing your mobile home’s foundation is as important as choosing the home itself. Assess your budget and choose the right foundation for you, according to your financing needs, the plot of land, and location. Permanent foundations are a more expensive option, but they can provide you with more financial and physical stability.
Related: Block Leveling a Mobile Home
Do you need assistance choosing the best foundation for your mobile home? Get in touch with Home Nation today! And, if you’re still searching for the manufactured home of your dreams, you won’t be disappointed with our selection or prices!
