There are three basic types of foundations in use today in the construction of a home.

Slab Foundations

A slab foundation is a foundation built immediately on the soil with no basement or crawl space. Slab foundations are common in areas where soil conditions are not OK for a basement, and are the most typical foundation found in warmer areas such as Florida, Arizona, California and Texas, or anywhere where the depth between the soil and stable underlying rock is very shallow. Slabs are the quickest and cheapest foundation because they require less work, ability and materials cost. They consist of a concrete slab that is sometimes six to 8 inches thick. Embedded within the slab is a grid of supporting ribbed metal rods known as "rebar." Even in locations where basements are prevalent, slab foundations are typically laid to serve as the base for structures like garages, pole barns, and outbuildings. Slabs are the least costly of the 3 main foundation types but provide no storage or utility space, as the home really sits without delay on a large platform of solid concrete. Slabs have the drawback of being hard and costly to fix when they settle and crack, and plumbing lines that protrude from the soil upward thru the concrete can also be expensive for a home foundation repair. In areas where the underlying soil is thick or subject to over the top enlargement and contraction, wires are embedded which can be tightened to provide better horizontal support and minimize the width of cracks.

Crawl Space (Pier and Beam ) Foundations

A pier and beam foundation contains either vertical wood or concrete columns (piers) that support beams or floor beams above the ground. The areas between the soil and the base of the house floor is thought of as the crawl space. These foundations are built either at floor zero or over a shallow excavation that varies in depth, but is commonly about 36 to forty inches deep. The best crawl space foundations have a load-bearing concrete perimeter wall and concrete or steel piers, both having footings below the freeze line of the soil, along with a good barrier over the soil to keep moisture in hand. Less expensive versions have no load-bearing perimeter walls, piers with shallow footings, and no moisture barrier at all over the soil. Crawl spaces that enclosed by a wall or by skirting must have vents on each side to allow air to circulate and help keep the soil dry under the home. These vents must be configured to prevent the entry of rodents and snakes. Crawl space foundations are most frequently employed in areas where there is heavy clay content in the soil that can severely damage (crack) slab foundations, or in waterfront or flood prone building sites where the necessary floor height to stop water penetration of the living space must be higher than a slab can typically provide. The first advantages of crawl space foundations are that plumbing lines are readily accessible for a foundation repairs and settlement issues are less complicated and more cost-effective to correct than with slab foundations. A primary drawback happens when these foundations are not properly maintained or are constructed without acceptable ventilation, allowing water or pests to cause damage. Crawl space foundations without acceptable insulation applied to the base of the house floor can be extraordinarily energy incompetent in a cold climate.

Basement Foundations

A basement is a type of foundation which includes an accessible space between the soil and the bottom of the 1st floor of a home. This foundation provides living space below the home, below the ground elevation. It is basically a slab foundation with walls and a floor. Basements are most frequently built in cold weather climates such as the Northeast, Midwest and Rocky Mountains, and in places where the price of excavation isn't prohibitive. Basements begin with a hole approximately 8 feet deep, some householders will opt for a nine or 10 foot deep basement wall to increase height and volume of useable space. The floor and walls are built, then the house itself is built over that. Basement foundations have the good thing about providing useful space for applications, mechanicals systems, and storage not available in the prior 2 kinds of foundations. The first downside of basements is that because they are mostly below ground level, they're exposed to leakage, mold formation, and flooding. Basements in wet climates must always have a working drain and pump in the floor to combat flooding.