Let’s say you’re planning to build a custom house. Do you care what type of foundation your house will have? Some homeowners leave this decision to the designer or builder. But if you’re reading this article, you’re probably the type of owner who wants to be involved in all the decisions related to your house — which means that you’ll want to learn as much as you can about foundations before making this decision.
In some rural areas of the country, installing a foundation is often a casual affair involving two contractors: an excavation contractor who digs a hole (or prepares the site) and a concrete contractor who sets up forms and places the concrete. In areas with tight regulations, however, as many as six experts may be involved in a residential foundation, including an architect, a structural engineer, a soils engineer, an excavation contractor, a concrete contractor, and a building inspector.
How many types of foundations are there? There is no agreed-upon system for categorizing foundations, of course, but I’m going to go with six different types.
1. Basement foundation. A basement foundation consists of a full story that is mostly below grade. These days, a basement usually has an 8-foot ceiling, although older basements may have lower ceilings, and some newer basements are 9 feet high. If the basement is built into a hillside, with the uphill side below grade and the downhill side exposed, it is called a “walkout basement.”
Although most new basement foundations have walls made of poured concrete, contractors in some parts of the country still build basement walls from concrete blocks (CMUs). Some older basements have walls made of stone and mortar, unmortared fieldstone, or brick.
A variation on the basement foundation is the permanent wood foundation (PWF) — basically,…