How Can I Change My House Foundation?

Reasons for Replacement

• If you merely want to change the appearance of your home's foundation, there are plenty of cosmetic ways to it, such as with paint, siding or a masonry or brick veneer. But a foundation that's failing structurally may need replacement. Examples would include a deteriorating concrete foundation or a foundation of brick or stone that's coming apart. According to Structural Dynamics Inc., a foundation restoration contractor in Illinois, most jobs involve replacing only one or two walls of the foundation.

No Lifting Necessary

• In most cases, a foundation contractor can replace a foundation without jacking the house up. Instead, workers go underneath the house and shore it up with supports. They place steel or wood beams below the home's ground-level floor joists, then install braces to hold the beams up. This way, the joists -- and the house -- remain exactly where they are. When the foundation is removed, the weight of the house transfers from the foundation to the beams and braces. The new foundation is then installed -- either poured as concrete or built from concrete blocks. The contractor then removes the beams and bracing, transferring the weight back to the new foundation.

Two at a Time

• In cases where the entire foundation needs replacing, the contractor typically won't take out the entire foundation at once. Say a house has four sides facing in the four compass directions: east, west, north and south. The contractor will shore up the house, then remove the foundation on two sides -- the north and east sides, for example. The new foundation walls are built on those sides, then the south and west sides are replaced. When all walls are done, the house is set back on the foundation.

Disruption

• Be warned that if you have a finished basement, it's going to be "unfinished" by the time the work is done, as the contractor will have to tear out the ceiling to get at the joists above and tear out the walls to get at the foundation. Disruption can be minimal for the rest of the house, though. If the house doesn't have to be lifted, then gas, power and water lines can remain connected, though shut off. But in some cases, such as when a house has slipped off its original foundation or when the original foundation wasn't high enough above ground level, the house may have to be lifted. The shoring beams are placed as normal, but instead of merely bracing them, the contractor uses hydraulic jacks to push the whole structure higher. Utility lines will have to be cut and replaced.