Repairing a Concrete Foundation

Tips from Real-Estate-Agents.com

Poured concrete foundations are created by pouring concrete into moldings. The footing for the foundation wall is generally wider than the wall, and it must rest on firm soil or on a gravel bed, with the base of the footing below the frost line (or in no-frost areas, at a minimum depth of 12 inches for a one-story house.) The footing should also have two half-inch reinforcing bars or rebar.

Concrete block foundations are created by assembling factory-made bricks of concrete with mortar. If you don't know what type of concrete foundation you have, just take a look at it. Concrete block foundations will have a regular pattern of square-ish bricks.

Depending on the size of the crack, a filler and waterproofing compound may be used to patch the hole from the inside. Waterproofing paint can help decrease the amount of seepage through walls, but it should be applied directly over concrete, not on a painted surface. Leaching water is moisture that slowly finds its way through the masonry wall via cracks, holes and mortar joints, usually because of improper or deteriorating waterproofing.

-- Tips courtesy of Service Magic