The three common foundation types found in the United States are basements, crawlspaces and slab-on grade. Basement foundations have foundation walls placed on footings . A crawlspace usually extends below the frost line or to a stable substrate. Crawlspaces are generally constructed with foundation walls and footings , however, piers may be used when the crawlspace is above grade.
Foundations transfer the weight or load of the house to the footings.
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