Bowing Basement walls - horizontal cracks
Posted by Jonathan Maguire on Tue, Nov 09, 2010
If you have experienced a horizontal crack in your basement block wall then you may have a foundation problem. Horizontal cracks or bowing walls indicate lateral pressures. On a basement wall, this is generally the soil and/or water from the outside of the house pushing the wall. When the pressure is great enough, the wall begins to fail, or bow inward.
Many engineers will diagnose this bowing wall problem as hydrostatic water pressure. Wet soils weigh about 3 times as much as dry soils. If there is not adequate drainage around the wall in question, then imagine every time it rains there is a force 3 times greater than normal pushing against the wall. Over time this pressure will cause most walls to bow or lean into the home.
Sometimes, the crack is due to a front porch settling or the crack occured during construction. If the crack is near the middle of the wall then hydrostatic water pressure is most likely the cause.
The solution may be two fold. 1) repairing the wall by either helical tieback anchors, wall anchors or carbon fiber reinforcing strips AND 2) grading, evaluating drainage, waterproofing to relieve the pressure.
Each structure is different so either contact a contractor skilled in these types of repair or hire a licensed professional engineer for an evaluation.