Usually, these cracks are “uniform” in terms of width but can sometimes be V-shaped. Wall shrinkage cracks are wide at the top but get smaller moving downward. They stop before they reach a wall’s bottom section.
Wall shrinkage foundation cracks are found beneath basement windows, near step-down areas, above doors, and on long walls (especially if they don’t feature control joints).
Benign as they look, these cracks can serve as entry points for water, leading to more damage and further foundation issues. Sometimes, though, they are harmless.
As concrete cures (chemical reaction caused by various factors), internal stress is inflicted onto the wall. Cracks occur here as internal stress relief. But what are some specific causes of wall shrinkage?
A poor concrete mix can result in this crack type. Even if there is proper steel reinforcement, the concrete needs to be of decent quality to properly support the foundation. However, without steel reinforcement, even the best concrete mix will fail to provide a proper foundation.
To an extent, concrete shrinkage is expected due to seasonal changes (concrete expanding and contracting). A good mix and carefully-placed steel reinforcement should help keep any crack-in-foundation type of a problem at bay.
Brick walls have also been known to cause wall shrinkage foundation cracks. Although brick walls won’t shrink, they will expand indefinitely, putting a lot of strain onto a foundation wall.
No, they don’t look nice. Still, shrinkage cracks don’t require remediation or monitoring. As mentioned earlier, though, wall shrinkage foundation cracks can cause water entry. To fix this, the crack is chipped out and filled with a sealant compound. Polyurethane foam, epoxy, masonry patching compound, and other sealants can be used here.