The choice of your home’s foundation is made based on the type of soil, terrain, weather conditions, and if you live in earthquake country.
The purpose of the foundation is to provide support to the rest of the house. So a house built on a slope needs to have a foundation that will keep the house from slipping down the hill.
In newer home structures, the foundation is isolated from the rest of the building preventing the harmonic motions of an earthquake from being transmitted to the rest of the building.
There are four main types of home foundations:
- poured concrete
- permanent wood
Poured concrete foundations are also called slab foundations, and are the most common because they’re inexpensive to build. One downside is that you can’t have a basement. Another is any plumbing, electrical, and heating ducts in the slab foundation are difficult to access. Eichler homes are notorious for the expensive problems caused when the radiant heating pipes in the slab foundation would leak or break. The good news is that the main floor in the home is sturdier. They don’t rot and deteriorate, sag or creak. If you want a heavy piano, floor safe, or waterbed, the floor can support it more easily.
Frost-protected foundations were designed for protecting the concrete in extremely cold conditions. It is a T-shaped foundation that provides extra support for the concrete slab with concrete footings extending below the frost line. They’re not very common in the US.
Permanent wood foundations have been around since the 1960s as an alternative for crawl space, basement and stem wall foundations. They’re easy to insulate and very moisture resistant. People often avoid this type because they don’t believe it will be as sturdy or reliable. A good home inspector can find issues, and these foundations are often better then you might think.
Raised foundations are mostly found in coastal areas that receive large amounts of rain. They must be able to both support the home and provide protection from the rain. The two types of raised foundations are pier-and-post (also called pier-and-beam) and stem wall. The difference between them is that the stem wall footings are continuous rather then spaced apart.
Manufactured homes are on the rise and have their own special foundation. The foundations have had to evolve over the years as manufactured houses have expanded into multiple stories.
What type of foundation do you have? If you’re looking for a new home, what kind are you going to look for?