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What Is Underpinning?

Underpinning refers to reinforcing the foundation of a structure, such as a house or building, by extending the existing foundation to distribute weight load across a greater area evenly. To begin this major repair project, soil directly beneath the foundation is excavated in stages to minimize the risk of undermining the structure. A foundation repair professional calculates the depth of excavation based on soil type and layer strength before replacing each layer with an underpinning material. This process continues until the complete structural base is reinforced, creating a stronger foundation for the building or structure.


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Cracked foundation

Changes in soil composition do affect the foundation of many buildings and structures. The culprit is often shrinking or weak soil. Because they’re shifty, the foundation has to be reinforced. Otherwise, it will settle, crack, or crumble. This isn’t good for a building’s structural integrity.

Let’s look at what is underpinning and the different types of underpinning products in the foundation repair industry.

When Is Underpinning Used?

It’s a good idea to know some of the reasons why homeowners underpin their foundations. This way, you can discuss underpinning with your foundation specialist, and see which option suits your home.

House settlement

A settling home will likely have gaps between walls and floor and out-of-level concrete. These signs aren’t just unsightly but can be hazardous if they’re not fixed. Underpinning your settling home brings stability to your house.

Poor workmanship

If a builder overlooks a step or takes shortcuts during construction, it can lead to a subpar-quality home. This can occur when the crew neglects to properly tamp down the soil, selects an unfavorable location, or fails to level the soil. However, you can consider yourself fortunate as underpinning can help address many of these issues.

Change in usage

When transforming a residential property into a commercial space, underpinning may be necessary to accommodate the increased foot traffic and installation or operation of heavy machinery or equipment.

Durable Underpinning Solutions

Here are several foundation pier solutions that can be used to strengthen your foundation and ensure the stability of your home:

  • Push piers: This popular type of pier is driven into the ground and permanently stabilizes the foundation, potentially even lifting it back to its original position. Made from galvanized steel, they resist rusting caused by ground moisture.
  • Helical piers: Similar to push piers, these are screwed into the ground and are ideal for lighter structures like porches and chimneys.
  • Slab piers: These are designed to support a slab foundation and prevent settling.

If your foundation is crumbling due to weak soils or any other issue, contact your local foundation experts for a free assessment. They will identify the problem and install the appropriate underpinning solution.