If you’ve read any of our other blogs about bowing basement walls, you know that repairing a bowed wall doesn’t have to include straightening it. In many cases, stabilizing and securing the wall is all that’s required to restore your foundation’s stability. We offer wall straightening as a service, but it’s not always necessary.
But every rule has its exceptions, and there are times when a wall can’t be repaired unless it is also straightened. Acculevel has helped more than 35,000 homeowners preserve and protect their homes since our start in 1996. We are a family-owned and operated company that specializes in waterproofing and foundation repair. When we work on your house, our goal is to treat your home as if it’s our own; we provide whole-home solutions that thoroughly address and resolve your concerns.
In this article, we’re going to explain what causes a wall to bow, when it’s necessary to excavate and straighten it, and how that process works.
Hydrostatic Pressure is the Most Likely Suspect
In most cases, your wall is bowing because of hydrostatic pressure. This is a formal way of saying that there is more water in the ground than the soil can absorb. The excess water then pools around your foundation and pushes against it.
Over time, the water pressure weakens your foundation. Cracks form, water may seep in, and eventually, the wall starts to bow (curve) inward.
This photo was taken by an Acculevel project advisor, during a free home assessment. The basement wall has cracked and is bowing inward.
If the wall isn’t bowing too far (less than 3 inches) and there isn’t any shearing (we’ll get to that in a minute), the wall can usually be repaired with carbon fiber straps.
Shearing Undermines Your Home’s Stability
Now that you understand how a basement wall can bow inward, let’s talk about shearing. This is something that only happens to concrete block walls.
Most of the time when a wall starts to bow, the mortar cracks more towards the center of the wall (like it did in the photo above). But if this doesn’t happen, a weak spot may form somewhere higher or lower in the wall.
Since the concrete floor of your basement helps hold the wall in place, it’s usually the block just above it that “gives way.” Shearing is the technical term for a wall that is sliding inward from hydrostatic pressure.
Illustration by the author, who is not a graphic designer
This is a major issue, because when a basement wall is shearing and bowing, that wall is no longer fully supporting the vertical load of the house. As the wall’s strength is eroded by the hydrostatic pressure, it becomes more vulnerable to collapse. It’s struggling against pressure from both the top (your home’s weight) and from the outside (excess water).
If the shearing is too significant (more than 3 inches inward), standard repair methods like carbon fiber straps alone are not going to be effective. The wall needs to be straightened before it can be secured with straps.
The Depth of Your Basement is Another Factor
In some cases, the first 2-3 feet of your basement is above grade (above the ground). But this isn’t true for most homes. If your basement is partially or entirely underground (it’s more common in multi-level houses or homes with walk-out basements), hydrostatic pressure can apply force to a wall closer to the top.
If your wall cracks and begins to bow near the top of the wall, this is a significant problem. In the rudimentary drawing below, you can clearly see how a wall bowing at a higher point undermines the support of the home.
The author is responsible for this illustration, too.
When the pressure is applied at a higher point in the wall, it can crack at the first or second block. This often means the wall bows more quickly and severely. This is another instance when the wall needs to be straightened before it can be repaired.
How Do You Straighten A Basement Wall?
Before beginning work on the wall, the first step is to use floor jacks to supplement the vertical support on the home. This stabilizes and protects your home while the basement wall is moved back into position.
Once it’s safe to do so, excavation along the outside of the wall can begin. When you remove the soil and water, you eliminate the hydrostatic pressure and relieve the horizontal strain against the wall.
Then, it’s time to straighten the wall. This is done by slowly pressing the wall back into position with hydraulic jacks and wooden braces.
Remember the photo from the beginning of this article? This is the same home, but now the wall has been straightened. Braces hold the wall in place, so the cracks in the wall can be filled.
Once the wall has been straightened, secured, and the cracks repaired, it’s time to install carbon fiber straps. You may wonder why- after all, the wall is fixed, right? The problem is, once a wall has been “broken,” it’s more likely to break again. Over time, hydrostatic pressure will build up again, and the crack that was repaired can re-open.
Carbon fiber straps will ensure that the wall remains in place. (The straps we use at Acculevel come with a warranty for the life of your structure.)
Again, this is the same home- but now the cracks have been repaired with epoxy and carbon fiber straps have been installed. FYI: both straps and epoxy can be painted over once dry.
You’ll notice that the braces have not been removed, yet. This is because it takes several days- sometimes more than a week- for the repairs to fully “cure.” The curing time depends on the humidity level of the basement. Once the repairs have fully set, the braces can be removed. As noted in the photo caption, the bright green of epoxy and straps can be painted over to match the other walls.
Does Your Basement Need Repairs?
If you live in Indiana or the surrounding areas, call Acculevel at 866-669-3349 or complete our online form to schedule an in-home consultation. Whether you’re dealing with water intrusion, large cracks, or a bowing/shearing wall, it is essential that you take prompt action. Foundation damage only gets worse (and more expensive to repair) as time passes.
When you schedule an in-home consultation with Acculevel, one of our knowledgeable and experienced project advisors will come to your home and discuss your concerns. They will thoroughly evaluate your home, help you formulate a plan to make any needed repairs, and answer all of your questions. We know your time is valuable and your home’s safety is our first priority. We want to ensure that we provide a whole-home solution for you, so that your greatest investment is protected for years to come.
If you do not live in our service area, please carefully evaluate the contractors in your area for the best possible fit. We strongly recommend that you verify the repair company is insured and accredited by the Better Business Bureau. You are welcome to also use our Questions To Ask A Contractor, a checklist of questions we have compiled to help homeowners protect themselves against potential scam artists posing as reputable contractors.