Bowing Wall Repair

Perhaps no better-known use for carbon fiber strips is fixing bowing walls.

carbon fiber used for bowing wall repair

The reasons are simple:

  1. It’s a common problem.
  2. It holds significant advantages over alternative repair methods.
  3. It works really, really well.

As a contractor, it provides the strength and reliability that you need, along with the ease of installation that will be appreciated by both you and your clients.

Carbon Fiber Has the Strength Needed to Stabilize Walls

With a tensile strength of 195,000 psi —more than 45,000 pounds per carbon fiber strap —carbon fiber is simply stronger than steel.

It is also lighter, easier to transport, and easier to install.

This strength gives it a 4X safety factor, allowing it to withstand the force applied to the wall by standard soil.

This is enough to arrest the inward movement of the wall and allow for the repair of any cracks.

Advantages of Using Carbon Fiber to Fix Bowing Walls

Aesthetics

One of the most significant advantages of carbon fiber for homeowners is that it solves the problem without detracting from the basement.

You don’t have I-beams sticking out into the room. You don’t have the large metal plates on the wall that come with tiebacks.

Carbon Fiber strips are applied flush to the wall and can be painted or drywalled over. No loss of space. No poor aesthetics. No constant reminder of their home’s past structural problems.

Carbon fiber used to stabilize a bowing wall

Ease of Installation

First, the carbon fiber installation is done entirely indoors, removing weather variables from the equation.

Second, carbon fiber is much lighter than steel I-beams or even tiebacks. That means less wear and tear on your vehicles and, more importantly, you and your employees.

Finally, unlike tiebacks or wall anchors, no excavations are required, and therefore, no additional machinery is needed. From a homeowner’s perspective, it also means no landscaping needs to be torn out. From your perspective, this improves safety and reduces your liability, as you don’t have to worry about hitting any utility lines running through the yard as you dig.

 

Fewer Callbacks

No contractor likes being called back to a job for a repair that didn’t last. The alternative methods of basement wall repair to carbon fiber each have weaknesses that can lead to callbacks, even if the repair itself holds.

With steel I-beams, the wall is only supported at the point where it is most bowed. And, as strong as steel is, it also tends to flex slightly before reaching peak strength. These two factors can cause sufficient movement to reopen cracks. And if the cracks reopen, even if the wall is structurally sound, there is a good chance the homeowner will look to you to fix them.

Tiebacks and Wall Anchors only stabilize the wall in the part with the interior plate. Unlike carbon fiber straps or even I-beams, they don’t support the wall's entire height. This can lead to cracks and other problems appearing above and below the interior wall plate, which, again, is likely to spur a callback.

Installation Method for Carbon Fiber on Bowing Walls

  1. Carbon Fiber Layout
    Determine the placement of the Carbon Fiber Support based on the engineer's specifications. The typical layout is 48” on center spacing.
  2. Surface Preparation
    Grind approximately 1/8” off the block wall to provide a clean, smooth substrate, removing all pliable coatings on walls and exposing the aggregate. A dustless grinding system is recommended that meets or exceeds OSHA standards.
  3. Fill All Cracks
    Seal all cracks in the wall with a non-pliable product and level as needed to provide a clean, smooth surface for the carbon fiber.
  4. Prepare the Base Connection
    There are two options for the base connection. In most cases, drill a hole in the floor at the base of the wall, centered on where the carbon fiber will be applied (or, if the floor has been removed, drill the hole directly into the footer). Later in the installation process, the bottom of the carbon fiber will be fashioned into a point and secured with the 3" SupportBar to anchor the bottom of the carbon fiber strip. In cases where shearing has already occurred or where there is a serious concern that the wall will shear, drill a hole into the cinder block wall three courses up from the footing. Then, insert a rebar support into the hole so that it sits on the footing. When this is done, fill the cores of the blocks with grout through the drilled hole.
  5. Install the Top Connection
    Pre-drill the sill plate where the carbon fiber strip is to be applied for the insertion of 2” lag bolts. Then install the bracket on the sill plate, but don’t tighten it yet. Loop about 12 inches of the carbon fiber strip around the support bar. Feed both ends behind the bracket to lock/anchor the carbon fiber in place. Chemically bond the carbon fiber strip to the wall and bracket with structural epoxy, then tighten the bolts on the top bracket to secure it to the sill plate. This will prevent the carbon fiber from pulling/shearing under pressure.
  6. Apply the Structural Epoxy to the Wall
    Apply the epoxy resin to the wall where the carbon fiber is to be installed, using vertical mortar joints as a guide.
  7. Adhere the Carbon Fiber to the Wall
    After applying a base layer of epoxy resin to the wall, apply the carbon fiber strip. Apply more resin over the carbon fiber, using a trowel to saturate the strip thoroughly.
  8. Attach the Base Connection
    Fold the bottom 5" of carbon fiber into a point with the folds of the carbon fiber facing out. Fill the pre-drilled base connection hole halfway with epoxy and insert the folded carbon fiber. Once the carbon fiber is installed, insert the 3" Support Bar, making sure it is flush with the slab. If necessary, add epoxy to fill the drilled area flush with the slab surface.
  9. Allow Time to Cure
    The epoxy resin will then need time to cure to solidify the bond between the carbon fiber and the wall.

Carbon Fiber Support Supplies Premium Carbon Fiber Products

If you’re looking for a reliable, contractor-friendly solution for stabilizing bowing basement walls, Carbon Fiber Support has your back. Our high-strength, easy-to-install carbon fiber system is designed to reduce callbacks, simplify your workflow, and deliver lasting results your clients will appreciate.

Contact us today to request product specs, get installation support, or place an order. More substantial repairs start with more innovative materials.