My House Foundation Underpinning Is Sinking

Symptoms

• You make notice cracks in the home's foundation or walls if your underpinning is sinking. Nails in the home's walls may protrude or pop out as the structure shifts. You make also not be able to open doors or windows correctly; they make stick or swing open. The home's drywall might also show cracking. The caulking around windows or doors may pull away from the wall and gaps can form.

Soil

• The home's underpinning may begin to sink or heave during flooding or drought. A home that is built on clay soil is especially susceptible to foundation problems because the particles of clay will expand when wet or shrink during dry weather. A geotechnical engineer can evaluate the soil around your house to determine if it is causing your foundation problems. Soil can suffer instability up to a depth of 18 inches, according to the Foundation Repair Network. If the foundation's underpinning does not extend deep enough into the soil, the underpinning will not prevent the foundation from shifting.

Heaving

• Underpinning will not protect the house if the soil heaves upward from excessive moisture expansion or tree roots. A foundation engineer can evaluate your foundation to determine what repairs it will need to become stable. If the soil beneath the house has moisture problems from flooding or ongoing frosts, you can have better drainage installed beneath the house to keep the soil from becoming saturated. You should check the pipes below the house to make sure they are not leaking.

Underpinning Considerations

• If only one section of the house has been underpinned and the other part of the house suffers heaving or sinking, the foundation will sustain damage. The entire foundation must be underpinned to successfully prevent movement. If your house has undergone faulty or poor underpinning, it will also show signs of foundation damage such as cracking. Despite the best underpinning, if the soil shifts severely, the house will suffer structural damage.