When external pressure on foundation walls becomes too great, walls can begin to bow in the middle, tilt along the top or slide along the bottom. The soil in the Kansas City area is made up predominantly of expansive clays – they swell or heave when inundated with water and shrink when dried. Swell pressure can occur when the soil becomes over-saturated, weakening the wall and pushing it inward.
Pier Masters has performed thousands of repairs on bowed walls, straightening the walls and strengthening them to resist external pressure in the future.
Repair methods for bowed walls can include:
- Helical Tiebacks: Also called helical wall anchors, this is a pre-engineered anchoring system to stabilize and/or straighten and strengthen bowing walls. The anchors are screwed at an angle into the ground, bypassing unstable soil until competent soil is reached. The other end of the anchor is attached to an anchor bolt and steel plate on the interior side of the wall. These plates hold the anchors in place, supporting and repairing the damaged wall. Depending on the severity of the bowing and the size of the affected area, a series of tiebacks can be installed along one wall.
- Steel Beam Vertical Wall Restraints: A steel beam that is installed vertically against a wall, connected to the floor joists above and the concrete slab below.
- Carbon Fiber Vertical Wall Restraints: This installation method doesn’t require excavation and bonds flat to the wall.
Helical tiebacks can also be used for new construction projects as prevention for failing, bowing walls. For more information on how helical tiebacks work, visit our Resources section: Resources-Helical Tiebacks
The video below shows a Pier Masters crew installing helical tiebacks on a bowing foundation wall, along with a waterproofing system. The time lapse allows viewers to see the wall actually being straightened.