Rules for How to Underpin the Foundation for a House

Consult with an unbiased structural engineer who specializes in this area about the need to underpin the foundation of your home and the most effective methods, since it can be difficult to assess the exact efficacy of the underpinning process.

Take the soil that surrounds your home into consideration by conducting a professional analysis. A professional can tell you about the type of soil that surrounds your foundation, as well as its moisture history, reactivity and variability. Because a soil investigation is crucial to the success of the foundation underpinning, seek a second soil analysis from a separate, unbiased professional. Having two analyses to compare with a structural engineer can help you make a more informed decision regarding the method to underpin the foundation of your home.

Verify the service lines that you may encounter before you begin to dig to underpin your home’s foundation. The lines can include those for gas, electricity and water.

Avoid simply filling in the cracks in your foundation with matching bricks or mortar because doing so may not reinforce the footing sufficiently. Instead, use piles when the soil near the surface is weak or build a basement constructed from reinforced concrete. Like vaults or brick cellars, the cement of the basement compensates for the weight of the building. An alternative includes using shallow spread footings when the ground has the capacity to support a home. Shallow spread footings can come in the form of concrete pads or rafts, which help spread the weight of the building past the unstable portion of topsoil.

Ensure that the underpinning pits cannot become gassed or flooded when you dig. This is particularly important if individuals will work inside the pits. Such pits should also have adequate ventilation and be simple to escape from.

Use threaded couplers in lieu of dowel bars to connect the reinforcement rods that are between sections of shallow concrete. Buildingconservation.com states that threaded couplers will make the underpinning process safer.