About Foundation Underpinnings

Underpinning is a method that is used to increase the depth of the foundation or repair a faulty foundation. When you have something as important as a building or house to protect, it’s good to know how you can protect and repair the foundation. Here’s what you should know about foundation underpinnings.

What is Foundation Underpinning?

Foundation underpinning is used to increase the depth of an existing foundation or repair a faulty foundation of a building or other structure. Increasing the depth of a foundation leads to greater stability. Underpinning is done by using a foundation repair method like mudjacking, wall anchors, and piering.

Sometimes a couple of methods are used if the situation requires it. The type of underpinning that needs to be done should be determined by a professional who can assess the situation. The benefits of underpinning include preservation of a structure’s integrity, increased ceiling height, the ability to change the use of a building (going from residential to commercial), and adding floors.

Types of Foundation Underpinning

Underpinning can be done by using methods that include piering, wall anchors, and mudjacking. Piering can be done using round shaft piers, square shaft piers, or concrete piles. The type chosen depends on the circumstance.

Round shaft piers are used in situations where compression application is required. Round shaft piers have a higher resistance to bending than other options. Square shaft piers are ideal for tension applications. The downside to the square shaft is they bend under pressure. Concrete piles are driven into the ground. They can be cast either before or after installation. If cast while in the ground, a cylindrical shell is placed in the ground and filled with concrete.

Helical wall anchors use square shafts and are used in tension applications. Wall anchors provide lateral support for the walls of the foundation. The benefit of using wall anchors is that they can be used in more confined spaces as they don’t require large machinery for installation.

Mudjacking, also known as slab-jacking, is a method where concrete is pumped under the foundation slab to lift it and the building it supports back into place. This method may work short-term, but over time the foundation and building may shift again. To use mudjacking as a long-term solution, another method such as piering, which goes deep into the bedrock, should be used. This will provide more stability to the foundation and structure that it supports.

Signs Underpinning is Required

One of the visible signs that underpinning is needed are cracks, especially diagonal cracks, in the foundation. Underpinning is necessary when the cracks become larger than 1/4 inch wide. Other signs that the foundation needs underpinning includes: walls that are detaching from the ceiling, walls are buckling, and windows and doors stick. When walls begin to detach from the ceiling, prompt foundation repair is needed otherwise they will continue to separate causing extensive damage.

Underpinning can be an important part of repairing and keeping a foundation sturdy and a building safe. Please contact us for more information.