Concrete Crack Repair

Cause: These cracks result from the natural drying and curing process of freshly poured concrete. As water evaporates, the concrete shrinks, leading to small, often fine cracks on the surface.

Appearance: Generally superficial and do not compromise structural integrity

Prevention: Proper curing practices and the use of shrinkage-reducing additives in the concrete mix can help reduce the chance of these cracks

Cause: Form when excessive weight is placed on a concrete slab. Concrete is strong, but too much weight can crush it.

Appearance: Typically occur due to excess overload on the ground beneath the slab (e.g., dumpsters, heavy equipment).

Pro Tip: The PSI rating of a concrete mix indicates its strength.

Cause: Hairline cracks form due to concrete settling while it’s curing.

Appearance: They are usually very thin cracks, but they can run very deep in the slab, as well. Because hairline cracks run deep, they pose a risk for more serious cracking once the concrete has hardened.

Prevention: As water and moisture make their way deep into the cracks and freeze as temperatures drop, the water and moisture expand. This expansion causes the cracks to widen and get a little bit worse after every freeze-thaw cycle. Properly maintaining a good seal in a crack can protect against additional damage from freeze-thaw cycles.

Cause: The soil under a new concrete slab is very rarely properly compacted before the new concrete is poured on top. As a result, settling slab cracks can occur. These cracks are caused by the gradual settling of the soil beneath the slab, leading to uneven support.

Appearance: These cracks can vary in size from thin to thick and vary in length. They will usually start out small, letting you know there is an issue occurring under the concrete slab.

Pro Tip: Settling slab cracks can affect the stability of the structure and should be addressed promptly. Polyurethane foam should be used for void filling and necessary lifting to level the slab if any settling has occurred.

Cause: Expansion cracks occur due to temperature changes. When concrete heats up, it expands, and when it cools down, it contracts. These temperature-induced movements can lead to cracks.

Appearance: These are usually in or around the expansion joints and can vary in size. This is what expansion joints are for and can be considered normal; however, it can also be a sign of settling (refer to previous statement).

Prevention: Proper joint placement and control joints can help manage expansion and contraction stresses in concrete.

Cause: Heaving cracks are caused by the expansion of concrete due to moisture or frost action. When water freezes, it expands, exerting pressure on the concrete. This pressure can cause the concrete to heave and crack.

Prevention: Proper drainage and insulation can help prevent heaving cracks.

Pro Tip: Remember that some cracks are superficial and don’t impact the structure significantly, while others may require professional assessment and repair. Regular inspection and maintenance can help identify and address concrete cracks early on.