Thread: Settlement cracks in basement block wall

Anybody have any thoughts on these settlement cracks in basement wall. House was built in 1961. I saw no evidence of water entry coming from the cracks. The separation was about 3/16". Should I have any reason for concern?

You don't mention if there is any inward bowing of the wall or exactly how far below grade the crack is or how long horizontally the crack is.

Horizontal cracking in concrete block wall would be a concern as there maybe be lateral forces acting on the wall. An engineer should be consulted as the crack may be stable or active. If its active it requires a fix.

Originally Posted by Raymond Wand

You don't mention if there is any inward bowing of the wall or exactly how far below grade the crack is or how long horizontally the crack is.

Horizontal cracking in concrete block wall would be a concern as there maybe be lateral forces acting on the wall. An engineer should be consulted as the crack may be stable or active. If its active it requires a fix.

Yes a slight inward bow, crack is about 20 ft (almost the total length of wall) and about 3 ft below grade)

Yep, needs to be fixed. I generally don't recommend engineers for this. I just tell the clients to have it repaired by a foundation specialist. Around here it generally costs about $100 per foot to anchor the wall.

Because its a bowed basement wall in some jurisdictions the building department will require building permit along with an engineered solution.

Originally Posted by Ken Rowe

Yep, needs to be fixed. I generally don't recommend engineers for this. I just tell the clients to have it repaired by a foundation specialist. Around here it generally costs about $100 per foot to anchor the wall.

How do they anchor? $100 per square foot?

Originally Posted by Sam Morris

Anybody have any thoughts on these settlement cracks in basement wall. House was built in 1961. I saw no evidence of water entry coming from the cracks. The separation was about 3/16". Should I have any reason for concern?

Horizontal cracks are always cause for some concern, because the crack would not exist if the wall had not moved inward or outward in some cases. 3/16" is not that small for a crack of that type. Other factors come into play. Sandy or clayey soil, 8", 10", 12" thick, height of backfill. As an example, with an 8" thick hollow block wall and Silty-clayey backfill the maximum backfill height would be about 4 to 5 feet. If the wall is backfilled to near the top then the wall is significantly under-designed. I am familiar with a number of cases where foundation walls failed suddenly and collapsed.