In this article, we’re going to discuss both the procedures used in foundation stabilization and the cost of stabilizing a foundation. We’re also going to talk about the causes and signs of foundation destabilization, which areas of the US are more likely to see problems, buying and selling a home with foundation stabilization issues, and more.

Photo of a Bay Area Underpinning truck parked in front of a house.

Foundation Stabilization: Foundation Repair Methods Compared

Foundations are important. In fact, they’re so important that the structural integrity of any building rests – literally – on the soundness of its foundation, and that depends on the strength of the soil underneath the foundation. Expansive soils and water are probably the two most common causes of foundation problems. We’ll talk more about this in just a bit. But right now, let’s talk about how to stabilize a foundation. The different types of foundation repairs include:

Photo of a push pier

Push piers
Installing push piers is a minimally-invasive procedure that first of all involves attaching heavy-duty steel brackets to the bottom of the foundation. Steel piers are then hydraulically driven through the brackets until they reach load-bearing soil. Once they’re in place, the foundation is hydraulically lifted and leveled and the weight of the structure is transferred from the unstable soil to competent, load bearing strata.

Photo of a helical pier

Helical foundation piers
Helical piers look like giant screws and are turned into the ground until they reach the required depth and torque for the particular foundation stabilization project. They’re good for projects requiring a deep foundation, and they don’t take very long to install. They’re also typically less expensive than traditional concrete piers.

photo of a drilled concrete pier

Drilled concrete foundation piers
Homes built on the sides of hills can experience foundation settlement and lateral movement due to soil creep. When this happens, you’ll notice the common signs of settlement, including sloped floors, doors and windows that are hard to open and close, etc. These foundations can be stabilized using concrete piers drilled deep down into the bedrock.

Photo of a slab pier

Slab Pier

Screw jacks
Sometimes a home might have signs of settlement even though the foundation is perfectly sound. Usually, this happens because either the screw jacks in the crawl space have deteriorated, or the crawl space’s support posts have settled. This problem can be fixed using the existing pier blocks and just removing and replacing the posts or screw jacks. At that point, the floor can be lifted back up.

How much does foundation stabilization cost?

The cost of foundation stabilization depends on a variety of factors, including – but not limited to – the type of problem and severity, the repair solution, and your geographical location. Because of this, we can’t give you a ballpark figure.

For a repair cost estimate, contact an experienced foundation repair contractor in your area and ask for an inspection. Most will do it for free and then offer you an estimate on the cost to repair the damage.

Some people worry that an unscrupulous foundation repair contractor might suggest unnecessary work. If you’re concerned about this, you can contact a structural engineer for an inspection. That person will give you a detailed report about what’s wrong with the foundation and include a suggested repair solution. You can then submit this report to the foundation repair contractor.

What causes foundation destabilization?

You may be surprised to hear that most foundation problems are caused by water, either too much or too little of it. Expansive soils are also a big problem because they swell a lot as they absorb moisture and shrink as they dry out. This swelling-shrinking cycle is usually a seasonal phenomenon, and it causes movement in the soil under the foundation. Since this movement is rarely uniform, it will eventually cause differential settlement.

A foundation is more likely to suffer damage if it’s:

  • Built on top of expansive soil – Expansive soils are those with a lot of clay or silt in them.
  • Built on top of sandy soil – Sandy soil is more susceptible to erosion which can lead to voids under the foundation.
  • Built on top of soil that wasn’t adequately compacted (soil stabilization) before construction
  • Built on top of soil with poor drainage
  • In an area with extreme seasonal weather changes
  • Surrounded by trees – Trees growing near a foundation suck up water from the soil and cause it to dry out and shrink, destabilizing the foundation.

An infographic with information about soil types and foundation construction

Which areas of the US are more susceptible to foundation destabilization?

Any region where the soil has a lot of clay, sand, or silt in it will present challenges when it comes to building sound foundations.

Soils with a high percentage of clay or silt in them are expansive. They expand significantly when they absorb water and then shrink a lot when they dry out. This swelling-shrinking cycle creates movement in the soil, which puts stress on a foundation and can lead to differential settlement.

foundation settlement: uniform vs differential

While sandy soil isn’t expansive, it is subject to erosion, and this can create voids under a foundation, which can also lead to differential settlement.

The best soil for constructing foundations is loam, which contains equal measures of sand, silt, and clay. Of course, bedrock is also a preferred base on which to build a foundation.

Signs of foundation destabilization

Signs of a destabilized foundation include:

  • Windows and doors that stick
  • Uneven floors
  • Ceilings and floors that have separated from the wall
  • Floor cracks
  • Bowed walls
  • Wall cracks
  • Ceiling cracks
  • Wall rotation – Wall rotation happens when soil outside of a foundation wall becomes over-saturated with water. The outside edge of the foundation sinks into the soil while the inside edge – which is on drier soil – pulls up. This causes the wall to rotate.
  • Diagonal cracks that start from the corners of windows and doors and go up toward the ceiling.
  • Moldings that have separated from the wall or ceiling
  • Stairstep cracks in brick
  • Chimneys and porches that are separating from the house

How do I hire a repair contractor for foundation stabilization?

The first thing you should do is educate yourself about the various foundation repair methods. An educated consumer is a smart consumer who is less likely to be ripped off by an unscrupulous, fly-by-night contractor.

Make sure the contractor you hire is both licensed and insured, and don’t be swayed by lowball estimates. You also want to make sure the repair comes with a warranty. However, remember that the warranty is only as good as the company offering it. Finally, ask if the cost of the repair includes things like permits and engineering costs. You don’t want any surprises.

Buying and selling a home with foundation problems

If you’re in the market for a home, you should learn to spot the signs of foundation damage. If you’ve already found a home that you’re interested in, but it has foundation damage, you should have a foundation repair contractor inspect it and give you a repair estimate. You can then figure that into your offer.

For information about selling a home with foundation problems see our article How To Sell A House With Foundation Problems.

Foundation damage is serious business. Even what appears to be a minor issue can quickly turn into a major problem if it isn’t taken care of right away. Therefore, every homeowner should learn to spot the signs of foundation trouble and then take action immediately.

If your home has a foundation problem and you live in our service area, contact us today for a free inspection and estimate.