Driveway Slab Jacking

Slab jacking is a great repair method for addressing settlement and trip hazards in driveways.  Driveway slab jacking raises settled, uneven driveways back into position by injecting grout below them.  The grout is pumped under pressure, and gently lifts the driveway back into place.  

One of the most common places driveways settle is where they meet the carport or garage slab.  This is particularly a problem around homes with deep footings.  The deeper the footing (a basement having the deepest), the more fill that was placed under the driveway.  This fill material is usually not compacted well, so it settles with time.  This causes voids to develop below the driveway slabs.  The voids can’t support the concrete, so it starts to sink.  Driveway slab jacking fills these voids and then gently lifts the driveway slabs back into place.

How Slab Jacking Works

photo taken before driveway slab jacking

Settled driveway prior to slab jacking.

Slab jacking works by pumping grout below the driveway to gently push it back up into place.  In situations where a tree root has raised a section of driveway, we can not push that area back down.  However, we use slab jacking to raise the adjacent slabs to address the trip hazards.  Sometimes, if a driveway has been raised above something that can’t be mudjacked, such as a door threshold, then the driveway needs to be replaced.

Driveway slab jacking usually requires drilling holes on 3 foot centers through the affected driveway slabs.  Grout is pumped through the holes to fill voids and lift the driveway.  After the grout pumping is done, the holes are cleaned out, and patched with concrete.  You may walk on the driveway immediately afterwards.  Depending on how much the slabs had to be lifted, you may need to wait a few hours to drive over the repaired area.  You can always drive over a slab that’s been repaired using slab jacking the day afterwards.

Concrete Jack’s slab jacking crews carry different colors of cement and sand on their trucks. This is in order to match patches to the color and texture of the existing slab as closely as possible.  It takes time of the patches to age and match dirty concrete, though.  Either way, the patches are much less noticeable than large sections of replaced concrete.

Benefits of Driveway Slab Jacking

The benefits of using slab jacking instead of replacement are numerous:

  1. Cost.  Slab jacking is significantly less expensive than replacement
  2. Disruption.  Slab jacking is much quicker and less disruptive than replacement
  3. No loss of use.  With slab jacking, you can walk on a driveway during slab jacking, and right afterwards, and drive on it within a few hours, if not immediately.
  4. Warranty.  We warranty most driveway slab jacking repairs.  Try finding replacement contractor that will provide a written warranty.
  5. Environmentally friendly.  Slab jacking is better than replacement for the environment because concrete is recycled in place.

Alternatives of Slab Jacking

Foam jacking as an alternative to driveway slab jacking

B&A of driveway foam jacking

Foam jacking is a similar process, which uses high density polyurethane instead of grout as the lifting material.  Where as most sidewalk repairs are done with slab jacking, most driveway repairs are done with foam jacking.  Concrete Jack’s estimators always recommend the most appropriate repair for a project, whether driveway slab jacking or driveway foam jacking.

Cost of Driveway Slab Jacking

Using slab jacking to raise a settled or correct unevenness in a driveway usually costs around 1/4 to 1/2 the cost of replacing the same area.  You can request a free quote from Concrete Jack for your driveway slab jacking project.  Please note that we only work in Virginia, Maryland, DC & The OBX.  This post has more information about the cost of slab jacking.