Bowed basement walls result when a building’s foundation walls curve inwards to form a ‘bow’. The commonest cause of a leaning or bowing basement wall is disproportionate lateral pressure on the wall’s exterior. When the wall becomes unable to withstand the pressure, it starts to curve and may develop cracks or even disintegrate.
Bowing of the basement walls occurs because basement walls are always under pressure due to the weight of the dirt and rocks that surround them. Additionally, basement walls are subject to constant freezing and thawing cycles as a result of changes in climate. All these factors combined with soil movements below the basement affect the pressure that the basement walls experience. Three common causes of bowed basement walls are explained below.
Common causes of basement wall bowing
A predominantly clay soil base: Clay soil readily expands and contracts in accordance with moisture changes in the ground. The expanding and shrinking can result in differences in pressure and cause the basement walls to curve.
Frost: The presence of ice or frost in the soil that holds the basement walls can cause bowing as the soil shrinks or expands depending on weather changes.
Hydrostatic pressure: Hydrostatic pressure refers to the accumulation of water in the soil that surrounds the foundation wall of the basement. The accumulation of water adds more pressure to the walls, which can bend if the soil below them is not able to withstand the pressure.
How to fix your bowing walls
The good news is that bowed basement walls can be fixed by competent technicians. Repair of bowing basement walls can be done using three methods: the use of wall anchors, the use of a force wall brace, or the use carbon fiber. Each of these methods is explained below.
Wall anchors: The use of wall anchors is based on the fact that the commonest cause of wall bowing is disproportionate lateral pressure on the exterior. Wall anchors make it possible for the pressure to be spread evenly across the wall, thus stopping the inward movement and bottom stress of the wall.
Force wall brace: This technique involves using a brace that counters the external pressure that causes basement walls to curve. The brace is recommended where a wall plate cannot be used due to yard restrictions or other limitations.
Carbon fiber:Carbon fiber is not only virtually unbreakable but also doesn’t stretch. It is therefore very useful in straightening bowed basement walls and repairing cracks.