Concrete crack repair is also termed as slabjacking whereby concrete slabs are raised by filling voids and gaps underneath them. Typically, a mixture of sand, gravel, and cement are injected to fill these voids and the pressure it builds underneath allows the concrete to rise and level.
In certain cases, voids are filled with spray foam instead of the typical sand and gravel mixture. This process is known as foam jacking and while new as compared to the mudjacking process, it has been road tested for years and found to be effective, practical, cost-efficient and “green”.
In fact, the Department of Transportation has been using foam to stabilize bridge approaches, street intersections, airport runways and more. Today, concrete crack repair in homes and buildings are also addressed with this process saving homeowners thousands of dollars and endless frustration associated with older, inferior methods.
Here’s how foam jacking works:
One of the advantages of using foam for concrete repair and other related issues is the fact that it’s not messy. A self-contained unit, a truck to be specific, with one or two installers pulls up in front of your home and start the process by drilling penny size holes in the area that needs leveling. The holes are significantly smaller as compared to the holes drilled in the mudjacking process so they are easily patched and become less obvious after the job is done. After drilling the holes, injection posts are inserted to allow the foam to be easily injected.
After this, the crew pulls in their flexible hose attached to their truck and begins injecting spray foam to the injection posts which go straight to the holes. A generator, pump, and heater deliver a two-part polyurethane that’s formulated for aggressive expansion. Heated to maintain flow, the parts are not mixed until they reach the tip of the injection gun.
The moment spray foam is injected beneath the slab, it expands up to 20-25 times its original volume. The technician injects the foam in bursts to prevent over-lifting. When the lifting action ceases, he delivers another burst of foam. This is repeated until the desired level is reached. If you’ve ever installed spray foam as insulation in your home, the same process applies in foam jacking only this time, spray foam is applied in your driveway, pathway or foundation.
Another advantage of spray foam, as a concrete crack repair means is its ability to cover all voids and gaps underneath the slab. While its counterpart, mudjacking, also does the job of leveling sunken concrete, the mud injection forms a cone underneath the slab so some gaps and voids aren’t covered up. This increases the possibility of stress points and cracking not to mention unsightly borings.
Spray foam is the new and effective means to address concrete crack repair. It can lift and level sunken concrete for both residential and commercial applications. If you have damaged concrete slabs that are in need of repair, contact the nearest slabjacker near you and request for a spray foam application.