Repair cracks in your foundation

Every home is going to have cracks in its foundation. What’s important is figuring out when a crack is simply the house settling or whether it’s an indication of something more serious.

Identifying the direction and size of any crack will help you determine whether it’s something you can fix on your own or whether you need to call in the experts.

Pay attention to the crack’s direction
If your crack is horizontal, then breathe easy. Usually horizontal cracks are the least troublesome. Vertical cracks or those in the shape of a staircase are more worrisome since they usually signal a more serious problem.

Size does count
The real test of any crack is its size and placement. Smooth, even hairline, cracks are usually not serious and a quick repair is all that is needed to prevent them from turning into something more serious.

Any crack with an accompanying slant or bulge—in any direction—is serious. The same goes if the crack is large enough to put the tip of your pinky into or if it’s leaking water. These types of cracks need to be assessed by an expert before any repairs can be done. In this case you would call a foundation expert.

When horizontal cracks are a problem
Horizontal cracks are most common in concrete block and brick foundations, but they can also show up in poured concrete foundation. Usually they are the result of frost damage after freezing temperatures shrink the concrete, but they are also caused by excessive pressure on the foundation from wet soil.

Long, horizontal cracks extending the full length of any outside wall should be investigated closely. A bulging crack can indicate a wall sliding off its footing or other stresses on a supporting wall.

To test any horizontal crack, Eric Villeneuve, a foundation expert at Home Depot, recommends placing a level against the crack. “If there is a bulge of more than a centimetre (½ inch) or if the crack is pushing out one side creating a small ledge, then it’s not something that can be quickly repaired,” he says.