Underpinning

There can be several signs that a home is experiencing foundation settlement, including:

  • Cracks in drywall above windows and doors or in ceilings

  • Windows or doors that suddenly become difficult to open or close

  • Uneven, sloping, or buckled basement floors

These symptoms often indicate that part of the home’s foundation has begun to settle.

Foundation settlement occurs when the soil beneath the footing can no longer adequately support the weight of the structure above it. This can happen when soil compresses, shifts, becomes saturated with water or dries out. 

When this happens, the footing can lose support. As the structure continues to bear weight on the foundation, cracks may develop and sections of the home can begin to settle unevenly. This uneven movement—called differential settlement—can lead to further cracking and structural movement over time.

Construction site showing a support structure for a pipe in a deep excavated hole.
Close-up of a mechanical setup with metal pipes, fittings, a yellow Grip-Tite foundation system, and a wrench, mounted on a rough concrete wall.
Two workers are installing or repairing a foundation or concrete wall, using specialized equipment and wearing gloves in a construction setting.
Room with exposed flooring, cut holes in the floor, and machinery with hydraulic hoses, likely for plumbing or construction work.
Underground plumbing pipes with metal brackets mounted in a construction site with exposed concrete and dirt.
Multiple pier brackets installed in an excavated trench to support a settling foundation.
Pier system with hydraulic lines connected beneath the foundation during underpinning work.
Two underpinning brackets installed beneath the footing to stabilize and lift a foundation.
Pier bracket installation beside rigid foam insulation on an excavated foundation wall.

How Underpinning Works

In many cases, the long-term solution to foundation settlement is underpinning.

Underpinning is the process of strengthening and stabilizing an existing foundation by adding deeper structural support beneath it.

Working from an engineered plan, helical piers (also known as screw piles) are installed at specific locations around the foundation. These steel piles are advanced into the ground until they reach stable, load-bearing soil.

Once the piles are installed, specialized brackets are secured beneath the existing footing. These brackets transfer the weight of the structure onto the deeper, stable soil layers through the piles.

Depending on the engineered design and site conditions, the process can:

  • Stabilize the foundation to prevent further settlement

  • Lift portions of the structure back toward their original position

Helical pier bracket installed beneath a foundation footing during underpinning to stabilize and support a settling home.

At LETY Construction, every underpinning project follows an engineered plan designed specifically for the structure and soil conditions.

Our foreman and crew carefully advance each screw pile to stable, load-bearing soil before transferring the weight of the home onto the system.

Crew members driving a helical pier into the ground using excavator-mounted equipment during a residential foundation underpinning project.

FAQ

  • Some common warning signs of foundation settlement include:

    • Cracks in drywall above windows or doors

    • Cracks in foundation walls (specifically “V” shaped cracks that are wider at the top than the bottom)

    • Doors or windows that stick or won’t close properly

    • Sloping or uneven floors

    • Gaps forming between walls, ceilings, or trim

    These symptoms don’t always mean underpinning is required, but they should be evaluated by a professional to determine the cause.

  • In many cases, underpinning can lift the foundation, helping to close cracks and improve structural alignment.

    However, the primary goal of underpinning is to stabilize the foundation and prevent further movement. The amount of lift possible depends on factors such as the structure, soil conditions, and the extent of settlement.

  • Yes. When properly engineered and installed, underpinning provides a long-term structural solution.

  • Yes. The engineer evaluates the structure, soil conditions, and foundation movement to determine the appropriate pile locations and load requirements.

  • In some situations, piles can be installed from the inside of the basement, especially where exterior access is limited. However, we cannot lift if piles are installed from the inside, only stabilize.

    The best approach depends on the home’s design and site conditions.