How are slab foundations are structurally repaired

Structural foundation repair: what does it mean?

When engineers talk about repairing slab foundations structurally, they specifically mean underpinning the foundation. The term underpinning is a structural engineering term that means that structural supported is being added to the foundation.

How piers and piles make the foundation more stable

The structural support that is added is almost always piers or piles installed under the slab foundation. The piers and piles transfer much of the load to deeper soil that is less susceptible to shrinking and swelling than the soil closer to the surface. This makes the foundation stable than it would be if it were supported by the surface soils alone.

Piers and piles are used to make the foundation more level

After the foundation is underpinned, jacks can be used to lift the lower areas of the foundation. As the lower areas are lifted, the slab surface is made more level, or at least closer to the as-built condition.

The end result is a foundation that is more stable and more level

After the foundation is underpinned, it should be:

•More stable since it is not as susceptible to settlement due to normal weather related changes in the moisture of the surface soils.
•By lifting lower areas and closing brick veneer cracks, the foundation can be brought to a closer approximation of the as-built levelness