They are under your sidewalk. And could lurk under your driveway. They may even exist under your car at night. You can’t see it. You may not even be able to hear it. But they are there. And with each passing year, it gets worse. When it gets worse, it becomes wider and deeper. What is this thing that would keep you up at night if you knew it was there? It is a void. A void is a large gap or space under your concrete driveway, sidewalk, patio and garage floor.

Concrete Bridge

A void causes a concrete slab to act more as a bridge than a support. This “bridge” is not designed or constructed to act like a bridge. Over time, the concrete that supports cars and people will give way or sink. It does not take a large void to create big problems. Some of the indications that result from your concrete slab now serving as a bridge are visible. Some are not.

How do you know if you have a void under a slab?

Sometimes, the signs that you have a void are not obvious. Garage floors show the least visible sign of a void. A tell-tale sign that a void is under your garage floor is hearing or feeling it. When you drive over a garage void, you will hear the shallowness of the space under the floor. You may also feel a slight tremor in the concrete. Small cracks may also be visible on the garage floor.

Void under a Driveway

It will be more obvious if your driveway has a void underneath it. There may be longer, and deeperVoid under slab of concrete fixed by Concrete Raising Systems, Kansas City (816) 419-8306 cracks in your driveway (the longer you wait, the deeper and wider these cracks may become), the concrete slabs may be uneven, the concrete by your garage door may appear to have sunken, or the driveway by the street is now sunken or cracking. Or you may even see it on the side of the driveway. (which may not be home to a variety of critters!)

Void under the slab of a Patio.

Your concrete patio shows signs of a void when the steps to it have gaps larger than ½”. Most steps were created to code, which is 7 ¾” high. If your steps are larger than this, they may be sinking into a void that is there.

Sidewalk Voids

A void under a concrete sidewalk will be visible as uneven slabs and possibly show cracks in the slab’s surface.

Having a void under a garage floor or a sidewalk can be dangerous. Your car could actually sink into the hole that will be created beneath when the “bridge” gives out. Tripping on an uneven sidewalk could result in anything from a skinned knee to a broken wrist or hip. Not taking care of the voids in a timely manner will definitely be more expensive as the void expands with the years and it takes more polyurethane lifting foam to fill it.

Use Polyurethane Foam to repair a void.

What you can’t see can hurt you. It can hurt your car, your knees and your wallet. Contact the concrete repair specialists at Concrete Raising Systems today. They use polyurethane foam to lift and raise your concrete garage floors, sidewalks, driveways and patios. Unlike traditional mud, cement and water mud jacking, polyurethane will not sink, and it is impervious to the weather. Forty per cent of the jobs we have done are to raise concrete where traditional mud jacking failed, and when we raise your concrete with foam, it is raised for good!