What Is Foundation Underpinning?

December 16, 2013 Melanie Chaney

When it comes to residential or commercial buildings, foundation underpinning describes a way of stabilizing or strengthening the foundation of a structure. This is accomplished by redistributing or transferring the weight-bearing load of the building to a deeper or more competent soil level. Why would a building require foundation underpinning? Most commonly foundation underpinning is necessary because shifting soil or shrinking concrete has weakened the foundation to the point where it’s no longer strong or stable enough to support the structure.

One method of stabilizing the foundation is through concrete underpinning. In this process, larger concrete footings are poured under the existing footings. This method is not very effective, since it usually does not actually center the foundation over stable soil, so the soil will continue to move. Also, concrete underpinnings tend to shrink as they cure, leaving you with gaps between the new and old footings, which weakens the overall integrity of the structure.

Push pier systems or helical pier systems are two of the most effective foundation stabilization methods for several reasons:

· Can be installed year-round

· Installation can take place from either inside or outside the structure

· Rapid installation compared with other methods

· Minimal damage to the structure during installation

· Can often lift the foundation to its original state

· Effectively repairs cracks and other signs of foundation issues

· Permanent solution to foundation problems

Both push piers and helical piers use heavy-duty steel shafts and foundation brackets to reach the necessary soil depth. As the name suggests, push piers are driven hydraulically into the earth using the weight of the structure. Helical piers work like screws, with helical plates affixed to the shafts that allow them to be twisted down into the soil. Because helical piers do not require the use of the structure’s weight, they’re ideal for the foundation repair of porches, decks, and other lightweight structures that are not heavy enough to drive a push pier.

If you need foundation repairs, let one of our specialists assess the damage and determine what type of foundation underpinning would work best. Call Baird Foundation Repair at 210-534-4110.