As structural engineers, one of the most common residential concerns we see are cracking concrete basement walls. Because concrete materials are very solid, we often think any cracks that appear must be a serious concern. This isn’t necessarily true, certain cracks might not need any repairs at all. This blog will give you some signs to help you determine when your cracked concrete basement wall is affecting the building’s overall structure.
In general terms, there are typically three types of concrete cracking patterns we see often. These include vertical cracks, horizontal cracks and diagonal cracks.
Vertical cracks are often less of a problem than the other patterns. When vertical concrete cracks form, they essentially separate the wall into two walls side-by-side. The two walls can still support vertical loads above as well as horizontal loads applied by the surrounding soil outside your basement. From a structural standpoint, repairs may not be needed at all.
Horizontal cracks are the opposite extreme and are the most problematic. When a horizontal concrete crack forms, the wall separates into two stacked walls. This creates a hinge within the middle of the wall and the outside soil will eventually push the wall inwards. Signs for this often include the top portion of the wall leaning in or even the middle hinge bowing in. When this happens, the vertical loads above can no longer be transferred along the straight vertical direction and will create an additional rotational force that assists the concrete wall in collapsing faster.
Diagonal cracks are somewhat of a hybrid of the vertical and horizontal cracks mentioned above. If the diagonal is more vertical than horizontal, you may be okay for the reasons mentioned. If the diagonal is more horizontal than vertical, you are at the other extreme and the problematic internal hinge needs to be addressed with repairs.
If you have concrete basement wall cracks and aren’t sure if they need to be repaired, please give us a call and we’d be happy to come out and give it a look!