Are you looking for information about the different types of cracks in concrete slabs? If so, you’ve landed on the right page. This article will cover seven different types of cracks in concrete slabs, including those caused by tree roots, heaving, and settling.
Cracks in concrete slabs are pretty common. In fact, you should even expect them. They’re often caused by shrinkage during the concrete curing (i.e., hardening) process. However, they’re also caused by tree roots and temperature fluctuations. The good news is they can usually be repaired rather than digging up the slab and pouring fresh concrete.
It’s not always possible to know what caused a particular crack. You can minimize the chance of cracks in concrete slabs by having a good concrete mix, preparing the site correctly, and practicing good finishing.
Today, most cracked and uneven concrete slabs are lifted and leveled using a repair method known as polyurethane foam injection. The procedure involves drilling small, penny-sized holes in the concrete and then using the holes to inject the waterproof poly foam under the slab. As the foam begins to immediately expand, it fills the voids under the slab and lifts it back up, closing the cracks.
Polyurethane foam injection is a quick procedure, and most jobs usually take around three hours tops. Fifteen minutes after the repair is complete, the slab is ready for use again. Poly foam is stronger than the cement slurry used in an older concrete leveling technique called “mudjacking.”
Polyurethane foam is also used to fix cracks in concrete foundation slabs. Cracked, unlevel foundation slabs usually happen when there’s a problem with groundwater around the foundation. Drainage problems leading to excess water in the soil under and around the foundation or drought where there isn’t enough moisture in the soil are the main causes of foundation trouble. Both lead to a phenomenon called “differential settlement” (see above graphic) and cracks in the slab.
Fixing a crack in a concrete foundation slab often involves using slab piers. Slab piers are installed through the slab and anchor the foundation to load-bearing soil. This lifts interior walls that have started to settle.
For more information see, Normal Foundation Cracks: Is There Such a Thing?
If you’re worried about cracks in concrete slabs on your property and are in our service area, contact us today for an inspection and repair estimate.