Sidewalk Slab Jacking

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

photo of settled sidewalk before performing sidewalk slab jacking

Residential sidewalk before slab jacking.

How Slab Jacking Works

Slab jacking works by pumping grout below the sidewalk to gently push it back up into place.  In situations where a tree root has raised a section of sidewalk, 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 sidewalk has been raised above something that can’t be mudjacked, such as a door threshold, then the sidewalk needs to be replaced.

Sidewalk slab jacking usually requires drilling two or three holes per sidewalk slab.  Grout is pumped through the holes to fill voids and lift the sidewalk.  After the grout pumping is done, the holes are cleaned out, and patched with concrete.  You may walk on the sidewalk immediately afterwards.  Sometimes more holes are required if a slab is larger than normal or has settled in a twisting fashion.  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 Sidewalk 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 sidewalk during slab jacking, and right afterwards.
  4. Warranty.  We warranty most sidewalk 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, an alternative to sidewalk slab jacking

Foam jacking a sidewalk

Foam jacking is a similar process, which uses high density polyurethane instead of grout as the lifting material.  Foam jacking doesn’t work as well as slab jacking for repairing narrow sidewalks.  Concrete Jack does both foam jacking & slab jacking.  Our estimators are trained to determine which method is most appropriate and economical based on each individual job’s conditions.

Cost of Sidewalk Slab Jacking

Using slab jacking to raise a settled or correct unevenness in a sidewalk 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 sidewalk 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.