Repairing Cracked Foundations with a Cure to Match the Cause
Foundation walls made from concrete block and poured concrete are strong and extremely durable. But concrete isn’t flexible. Unlike the wood framing it typically supports, a concrete foundation wall can’t bend or flex when soil settles beneath a footing or when expansive soil outside the foundation pushes in on the wall.
Because concrete lacks tensile (bending) strength, it cracks rather than stretches. Tiny hairline cracks –too small to admit a credit card—sometimes occur during the curing process as concrete or mortar shrinks. Larger cracks occur in response to settling or expanding soil. There are several ways to repair these larger cracks, and it’s important to choose the right technique if you want your foundation to remain in good condition.
Using Patching Mortar
Thanks to the widespread availability of masonry sealants and patching compounds, many homeowners choose to repair narrow cracks themselves. Powdered and premixed patching compounds are available at home centers and hardware stores, as are masonry sealants that are applied with caulking guns.
This repair strategy is fast and less expensive than a professional repair. However, if the crack has occurred due to structural problems, the repair will not last and it won't prevent more severe cracking and foundation movement from happening.
Repairs With Polyurethane
This flexible, waterproof and highly adhesive compound can be applied as a sealant or in the form of expanding foam. Foundation repair contractors have application equipment that enables them to inject polyurethane deep into the crack to maximize the sealing effect.
This foam application is used to fill and seal larger cracks. It also does quite well at preventing water from leaking into the basement or crawl space, but it doesn't prevent the foundation from further settling, bowing or other movement.
Everyone Likes Epoxy
Like polyurethane, epoxy can be injected into a foundation wall so that this repair material can fill into the full depth of the crack. Epoxy forms a strong bond with the concrete. It will stop leaks just like polyurethane, and has greater structural value. However, it will not prevent additional cracks and foundation movement if the soil under and around the foundation is unstable.
The Strength of Piers
Experienced foundation repair contractors often install piers to overcome foundation cracks and movement being caused by unstable soil. Both push-type and helical piers stabilize foundations by connecting foundation footings, walls and slabs to more stable soil.
The piers extend through the unstable soil, anchoring solidly into bedrock or stable load-bearing soil at greater depth. If a foundation wall is bowed inward and cracking due to expansive soil, horizontal piers –called anchors—are driven into the soil to prevent further movement. Once the foundation has been stabilized, permanent crack repairs can be made with a high degree of confidence that the cracks won’t recur.
Contact the experts at Southeast Foundation Repair for more information about sealing and preventing additional cracks. They offer free estimates for foundation repair in North Carolina.
Southeast Foundation & Crawl Space Repair serves the greater areas of Greenville, Kinston, Havelock, Raeford, Washington, Clinton, Dunn, Camp Lejeune & Newport NC.