Poured foundation walls, the most common type in our service area, can almost always be counted on to crack. These cracks can occur due to conditions when the concrete is poured, soil conditions around the foundation as well as the shape of the foundation itself.
Typical foundation cracks, under 1/8” in thickness are expected, considered normal and not a major cause for structural concern. They can, however, be a source for water intrusion into the basement or crawlspace and should be fixed, whether actively leaking or not.
It is our experience that an existing foundation crack will eventually leak at some point.
You can expect cracks to form in a few typical places in a poured foundation wall. Cracks can appear near window and door openings, where sewer or waterlines pass through the foundation, where beams sit in the foundation wall or where the foundation wall turns a corner or has changed in elevation such as in a walk-out basement.
Diagnosing foundation cracks is pretty straightforward. In the case of an unfinished basement or crawlspace, they are easily seen because the foundation wall is exposed.
In the case of a finished basement, cracks can be identified by finding the first point of entry into the basement and looking at the exterior of the building.
Foundation cracks are predictable in that they almost always follow a relatively vertical path from the bottom of the foundation wall to the top and can be seen from the exterior where the foundation wall is visible above grade.
Once the foundation crack is located, a decision needs to be made…repair from the interior or the exterior?
If the basement or crawlspace foundation walls are accessible, a urethane crack injection is the preferred method of repair due to its relatively low cost and no need to excavate a portion of the exterior of the foundation wall. Another advantage of the urethane material is that it expands to fill the entire crack, effectively stopping the water on the exterior of the building.
Unlike epoxy injections, Urethane crack repairs, once cured, remain slightly flexible as well so the seasonal movement of the foundation wall caused by expanding soil conditions and frost do not compromise the repair. This flexibility allows Midwest Waterproofing to include a lifetime transferable warranty with all urethane crack repairs.
If the basement space is finished, an exterior option may be preferred if you do not want to cut open the wall to expose the crack or if mechanical equipment like furnaces and water heaters are in the way. There are two typical options for exterior crack repair, a waterproof membrane or a sodium bentonite clay application.
Our staff, with their years of experience, can help determine which crack repair method is right for your situation. If you want to learn more about foundation crack repairs, visit our Education Center.