Foundation Cracks

There are more than a few types of cracks that can be found in your foundation. Some are serious, while others are not. The trick is identifying what type of crack you are looking at in order to decide your next course of action.

Horizontal Cracks

A horizontal crack across your foundation is serious. It is usually due to unbalanced soil and water exerting pressure against the foundation wall. The foundation may bow inwards, and water may get into the home. These cracks are repairable if you catch them and have them looked at.

Stair Step Cracks

Cement block foundations are sometimes prone to stair step cracks. These tend to focus on the mortar joints and cause a potentially serious structural issue with your foundation. The causes of these are foundation settlement in one area, and moisture issues on the outside of the foundation.

Hairline Cracks

Hairline cracks are fairly common in new construction foundations. You usually notice them within a year, and are caused by settling and curing of the foundation. These cracks tend to be cosmetic only, with no structural issues. There are do it yourself kits for homeowners for a few hundred dollars. If you see such a crack and your home is still under warranty, contact the builder, as they should cover the repair.

Vertical Cracks

Vertical cracks in a foundation aren’t as serious as horizontal cracks and generally do not pose a threat to the structural integrity. These cracks are some of the most common found and are created by normal settling and the process of the concrete curing.

Diagonal Cracks

Diagonal cracks, like vertical, do not pose a threat to the structural integrity of the foundation. They run up to 30 degrees vertically and are caused by normal settling and curing. There are aftermarket DIY kits to repair these on your own with Epoxy crack injections.

Shrinkage Cracks

Like hairline cracks, shrinkage occurs when poured concrete foundations begin to dry out during the curing process and lose moisture. These are almost always vertical and cause no serious threat to your foundation.

As a homeowner, seeing any of these cracks will usually set off a bit of panic. Knowing what type it is can help you determine the course of action. Some things to remember is to document the size of the crack, taking a picture. Also helpful is using a tape measure to confirm if the crack is less than 2mm, which usually is not a concern. If you can fit a quarter into the crack, it needs attention. 

During a Home Inspection the Inspector will show you the crack and be able to identify the type and any concerns related to them. As with anything concerning foundations, the Inspector may refer you to a specialist, and if you are a homeowner with questions or are unsure of what you are looking at, calling a foundation specialist may be the smartest thing to do.