‘58 Foundations & Waterproofing offers three solutions to stabilize or repair a bowed basement wall. Each basement bracing solution is dictated by the depth of the bow and the intended result – stabilization or straightening. Walls that are bowed 4-inches or less can be saved. Walls that are bowed more than 4-inches may have to be reconstructed.
Carbon Fiber Strapping
When the bow of your wall is 2-inches or less, Carbon Fiber Strapping can be used. It is the least invasive stabilization technique. This 8-inch wide material is epoxied to your bowing wall to prevent any further movement.
First the wall is scarified, which means all paint and residue is removed from the wall to reveal a clean, porous surface. Then the Carbon Fiber material is soaked in epoxy and placed on the porous wall so it bonds tightly. Strips run from the top of the wall to the floor and are mechanically fastened to the wood framing and the slab. On a typical 8-foot wall with 7-foot of exterior backfill, the strips are placed 2-foot from the corner and then every 4-foot.
Steel I-Beam Reinforcement
On occasions where the basement wall is bowed up to 2-inches but not more than 4-inches, Steel I-Beams offer a very solid solution. Placed 2-foot from the corner and then every 4-foot, they are mechanically anchored top and bottom. Once installed, they are unforgiving and will not move.
Steel I-Beams are a perfect solution if your basement does not have a slab. In this instance, a 2-foot wide, 3-foot deep trench is dug out 2-feet from the wall. The I-Beams are placed in the trench and the void is filled with concrete to create a solid foundation.
You may lose some square footage if finishing your basement over the I-Beams, but when the I-Beam is secured against the bowing wall, it is very stable.
Helical Tieback Anchors
Helical Tiebacks are used in any instance of a wall bowing 4-inches or less and when you want to straighten the wall back to its original vertical position. Think of the Tieback as a giant ground screw. A long galvanized 1.25-inch diameter screw is driven through the wall and anchored into the ground outside. Inside, against the wall, a threaded plate (or C-channel bracket) is added.
If you excavate on the outside before you place the helical tieback, you may be able to actually draw the wall back up to vertical. This is accomplished by turning the helical tieback like a screw (before the dirt is replaced). This is the only solution that can potentially bring your wall back to plumb.