How to Raise a Sidewalk Slab Near the Garage

Drill two 1 1/2-inch drill holes in the sunken section of the sidewalk. The holes should be 1 foot in from both ends of the sidewalk and spaced 1 to 3 feet apart from each other down the length of the slab. Use a concrete core drill, and wear a face mask, safety glasses and ear plugs to protect yourself from harmful debris. The holes must go through the entire slab. Stop drilling when you feel the gravel or subsoil beneath.

Insert a hose with a 1 1/2-inch nozzle into the hole at the lower point in the slab until you feel resistance. Attach the other end of the hose to the slabjacking machine and clamp it in position.

Use pre-made grout mixed specifically for slabjacking. This contains cement, water, sand and special aggregates to prevent it from shrinking. Scoop the mix into the slabjacking machine with a scooper.

Turn the machine on and pump the grout into the hole. Once the expanse beneath the slab is filled, the machine will pressurize the grout to raise the slab.

Move the nozzle into the next hole once the first hole is filled. Continue to move the nozzle between each hole and pump grout until the slab rises to its original height.

Scrape any excess grout out of the drill holes with a putty knife. Fill the holes with stiff mortar and smooth the surface with the knife so it dries clean and level with the rest of the pavement. Do not allow foot traffic on the sidewalk for at least 24 hours to give the grout foundation time to set.