Ground water and rainwater can cause a lot of damage to a home. Building materials that are allowed to remain damp or saturated for long periods of time will eventually fail. Builders can take several steps to protect the home’s foundation. For example they can properly grade the site so water drains away from the home on all sides, install footing drains at the footing of the foundation walls that drain to daylight or to a French drain away from the home, build the foundation on a bed of aggregate rock, use a vapor barrier under slabs and on crawlspace floors, and damp-proof the exterior of foundation walls.