The Complete Basement Waterproofing Guide For Midwest Homeowners
Discover the most common ways water gets into your basement and what you can do to keep it dry.
What are bowing walls?
Put simply, bowing walls are basement or retaining walls that curve inward.
If we look at a cross-section of a wall and drop a plumb line from the top of the wall to its base, the plumb line shouldn’t fall outside the wall’s center of gravity at the base. (The wall’s center of gravity is the middle third of the wall’s thickness.) With bowing walls, the plumb line will fall outside the wall’s center of gravity. In other words, it will fall outside the middle third of the wall.
What causes bowing walls?
Bowing walls are caused by a variety of things including:
Expansive soil – Not all soils are alike. Expansive soils are those that swell as they absorb water, and shrink as they dry out. When the soil expands during the rainy season it puts pressure on the foundation wall, and over time this can result in bowing.
Hydrostatic pressure – Water-saturated soil outside your foundation creates hydrostatic pressure that pushes against the wall.
Frozen soil – When soil freezes, it expands and this exerts pressure against the wall.
Lateral pressure on the outside of the wall – This can happen when there’s – for example – a heavy vehicle parked next to the wall.
Bowing walls can also crack, as you see in the above photo. In fact, these types of wall cracks can even open and close depending on the weather conditions. They might open when it’s rainy, and then close as soon as the soil dries out, or vice versa.
Bowing walls: Repair options
There are a variety of ways to fix a bowing basement wall. The one chosen will depend on the severity of the bowing. We’ve grouped them here into wall anchor systems and bracing systems.
Wall anchors take the pressure off the wall and distribute it into the yard. This stops the wall from continuing to move inward. There are three different types of wall anchors: c-channel wall anchors, helical tie-back wall anchors, and wall plate anchor systems:
C-Channel Wall Anchors – C-channel anchors are typically used when there is “shearing” at the bottom of the wall. They are placed on the wall approximately every 4-5′, on center. (The term ‘’on center’’ means the distance from the middle of one wall anchor – or any other element – to the middle of the next.)
In our service area, which encompasses parts of Nebraska, Iowa, Kansas, and Missouri, the average C-channel job takes 1-2 days to complete.
Helical Tie-Back Wall Anchors – Helical tie backs are often used when a wall is leaning severely, tipping inward, or if a lot of recovery is trying to be achieved. They are placed on the wall approximately every 4-5′, on center. Helical tie backs usually require removing soil from the exterior of the house in order to take the pressure off the wall.
In our service area, the average helical tie back job takes about 3-4 days to complete.
Wall Plate Anchor System – Wall plate anchors are placed on the wall approximately every 5′, on center. In our service area, the average wall plate anchor system takes about 1-2 days to complete.
All of the above wall anchor solutions:
Are a permanent solution to stop failing foundation walls
Don’t take a lot of time to install
Can usually straighten the wall immediately with excavation, or possibly straighten the wall over time without excavation.
While all of the above solutions are designed to straighten bowed walls, we cannot guarantee 100% recovery. However, we do guarantee that all of the above solutions will permanently stabilize the wall.
Steel I-beams – Steel I-Beams don’t require excavation and are designed to straighten both block and concrete walls over time. At Epp Foundation Repair, we recommend them when wall plates can’t be used.
They are placed on the wall approximately every 4- 5’, on center. In our service area, the average job using steel I-beams takes 1-2 days to complete.
Carbon fiber wall repair – Carbon fiber is an extremely strong fabric material that doesn’t stretch and is virtually unbreakable. This makes it perfect for repairing bowed walls. The installation is fast, clean, and the straps can be used to stabilized both block and poured concrete foundations.
The carbon fiber straps are placed on the wall approximately every 4’, on center. The average repair job using carbon fiber wall straps takes 1-2 days to complete.
While carbon fiber straps work well for wall stabilization, they don’t straighten the wall. However, since they’re only 1/4” wide and can be painted after the job is done, you will hardly know they’re there.
What should I do if my basement wall is bowing?
As a general rule of thumb, when a wall is bowing or tilting inward more than 50% of its thickness – For example, an 8” thick wall bowing in more than 4” – the wall almost always needs to be demolished and replaced. Therefore, if you see a crack, or any movement whatsoever in a wall – no matter how slight – you should contact a foundation repair professional immediately for an inspection. In other words, you should never leave a wall unrepaired to the point where it ends up bowed. Any cracks or inward movement of a wall are not OK. The sooner you catch the problem, the less expensive it will be to fix.
You should also be sure to exercise caution around any wall with severe bowing or bulging.
Should I buy a house with bowing basement walls?
If you’re considering buying a house with one or more bowing walls, call either an experienced foundation repair contractor, or a structural engineer, and have them perform an inspection. They will be able to tell you what’s wrong, and how it can be fixed. The foundation repair contractor will also be able to give you an estimate of how much it will cost to fix the damage. You can then figure this into your offer.
Remember, bowing walls are a sign of structural damage. Never buy a house with bowing basement walls unless you first have the problem inspected by an experienced professional.