Foundation cracks are never a good sign. Whether or not you should worry completely depends on the crack and if it is structural or not. Obviously, some cracks call for more serious action than others. Not every foundation cracks is a sign your house is going to fall down but cracks should never be left alone or ignored.
Concrete cracks by nature will get worse with time. Even if it starts out a nonstructural crack, if it is left alone water will start penetrating the crack and erode the inside of the concrete wall. Even the smallest hairline cracks can let water into the basement. At the very least these cracks should be fixed with a concrete crack injection. Surface caulking is not good enough to treat concrete cracks. Concrete cracks need to be injected with pressurized crack injection material. The size and location of the crack will determine what type of material is needed. If the crack is simply leaking, a polyurethane material will work to stop the leak. If the crack is moving, then an epoxy-based material is recommended. Epoxy will bond to the concrete and create a more rigid material that will hold the crack in place. Many times contractors will use carbon fiber staples in addition to epoxy crack injection to fix small cracks that open and close over time moving with the freeze-thaw cycles.
Another way to tell you may have a structural crack is the location and arrangement of the crack.
Vertical Cracks
Vertical cracks are typically nonstructural in poured concrete walls. Typically, a vertical crack is caused by the natural freeze-thaw cycle as the concrete contracts and expands. These don’t cause for too much alarm as long as they are not leaking. A leaky crack can cause water damage, mold, and rot if left alone.
Horizontal Cracks
Horizontal cracks on the lower half of the basement wall is a sign that the crack is structural. If you see these types of cracks you may have a more serious foundation problem that needs to be addressed with a foundation repair contractor. Multiple cracks on adjacent foundation walls are also a sign the foundation is moving and the structural integrity may be compromised. Horizontal cracks are usually caused by pressure building up on the opposite side of the wall. Take care of the hydrostatic pressure issue with French drains, outside drainage systems and basement waterproofing. A foundation repair contractor who also does basement waterproofing can help you take care of both issues as once. If you repair your foundation without taking care of the water issue, you will have more foundation problems in the future.
These are some great things to consider, and I appreciate your information about vertical cracks. A couple of vertical cracks appeared on my foundation a few weeks ago, and at first I was worried about them. If they’re not leaking water, should I just leave them, or should I have them repaired anyway? Thanks for the great post!
I just moved into a new home that has an unfinished basement, and it has a few cracks in the concrete. I was told that they wouldn’t be a problem, but according to this information I think they are just vertical cracks. I will check when I get home to see if I should be worried about my basement. If I have any horizontal cracks I will make sure to get them fixed as soon as possible, thank you!