What are Modular Home Foundations?

When considering building a modular home, a critical decision is the type of foundation. Modular homes must be bolted to a foundation to keep them in place against the elements, also called a permanent perimeter foundation.

A modular home’s foundation is the base level of the building. It keeps the ground’s moisture away from the house and distributes the house’s weight equally from the load-bearing walls to the ground beneath. 

There are two preferred foundations for modular homes: crawl-space foundations and basement foundations. Let’s explore why the foundation is essential and home builders’ options.

Why is the Foundation Important for Modular Homes?

Building your home is no easy feat. It’s costly, takes up a lot of time, and requires a lot of decisions. Let’s see how we can make one decision a little less daunting.

In case you are not aware, a foundation is created by digging a hole in the ground and laying down a lot of cement. The home’s construction and assembly are on this foundation. The type of foundation dictates how the load will be distributed and is the deciding factor for what foundations modular homes can use.

A building’s foundation is an essential piece of any construction and is the link between the ground and your home. Without a proper foundation, the structure of a building will start to become unstable, putting your house at serious risk.

The foundation’s primary purpose is to support your building structure against moving and unstable soil. In addition, it prevents moisture from entering your building structure. It insulates your home against the ground’s cold. And it prevents insects from infiltrating your house.

It is worth noting that all basements need to adhere to (or exceed) local and state building codes. Foundations must be built below the frost line or be frost-protected.

What are the Two Types of Foundations for Modular Homes? 

As mentioned above, two main foundation options are available for a modular home. The first (and most popular option) is the crawl-space foundation. The second option is a basement foundation.

Basement and crawl-space foundation designs must match the modular home’s dimension, design, and shape. They effectively create a perfect fit from the modular home to the ground.

What is a Crawl-Space Foundation?

a modular home is being installed on a Crawl-Space Foundation

We’ve mentioned it a few times, but let’s dig deeper into what a crawl space foundation is. 

A crawl-space foundation allows for a small space between the ground and the foundation where enough space is left to crawl. The additional space provides room for electricity and plumbing channels in your home. 

Generally, a crawl-space foundation is less costly, requiring less concrete and less digging. In addition, no basement requires heating/cooling, meaning less electricity usage and long-term costs. Therefore, this type of foundation is the preferred option by modular home builders. 

What is a Basement Foundation?

a modular home is being installed on  a basement foundation

The other option available is the basement foundation. Although it is more expensive, it does have another range of functions to counter. 

A basement foundation is created by digging a large hole in the ground and lining the inner walls with concrete. The basement room is the foundation on which the builders will build your house. 

The basement is an additional room that your household can utilize. The most significant benefit of having a basement foundation is the added space. A feature the crawl-space foundation does not provide.

In addition, should tornadoes be a risk, you can use the basement as shelter. 

What Foundation Types Not To Use for Modular Homes?

We’ve discovered two preferred types of foundations for a modular home. Let’s now look at what foundations are either not regularly used or generally not recommended.

Can you Put a Modular Home on a Slab Foundation?

Although slab foundations are popular, they have a few drawbacks, specifically when using a slab foundation for your modular home. Slab foundations are poured directly on the ground (all at once) and straight into the ground. The result is a sizeable square-shaped layer of concrete. 

A modular home’s design doesn’t allow for construction on slab foundations. Modular home builders bolt the structure against the foundation; therefore, they are designed for basement or crawl space foundations. 

Slab foundations are a popular foundation type used in the on-site construction of buildings and houses, specifically in warmer climates. They are simple and cost-effective, and relatively quick to install. Laying the concrete for a slab foundation can be completed within a day, resulting in a complete foundation construction within three to four days (weather permitting). 

Can you Use a Pier Foundation for a Modular Home?

Pier foundations are popular among coastal regions as a caution against rising tides. The concept is similar to a raised deck. It is an elevated foundation, lifting the house above the ground with pillars. But can it be used for a modular home?

Manufactured homes can use pier foundations but not modular homes. A modular home must bolt against either a basement foundation or a crawl space foundation, specifically created on-site, to match the modular home’s design and dimensions.

Can you Use a Runner Foundation for a Modular Home?

By now, it should be obvious. Modular homes can only be placed on a basement or crawl space foundation. But what about a runner foundation?

Modular homes cannot be placed on runner foundations, as they are specifically created to be placed on either a basement or crawl space foundation. 

Runner foundations are similar to slab foundations. But, instead of one large slab, a runner foundation comprises multiple stretches of concrete that run from side to side.

Concluding remarks

Multiple foundations are available for home builders: Slab, runner, pier, crawl space, basement, and more. However, modular homes can only be placed on two types of foundations: Crawl space and basement foundations.

Basement and crawl space foundations allow for utilities underneath the house. They are created according to the dimensions and design of the modular home, which bolts onto the foundation.

The specifically created foundation with the bolted modular home establishes the strength and stability required for a modular home’s longevity.

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