How to Fix a Sinking Sidewalk
A sinking sidewalk is not only unsightly but also a safety hazard, increasing the chances of someone tripping on the uneven pavement. This issue arises because exterior concrete is constantly shifting due to natural factors like:
- Soil settling over time.
- Moisture fluctuations, causing soil to expand or shrink.
- Frost heave in colder climates, which lifts and disrupts concrete slabs.
The Problem with Full Replacement
Replacing a sidewalk or driveway involves removing the existing concrete and installing new concrete. Ask the contractor how removed material will be handled: the EPA identifies concrete as a recoverable demolition material, with recycling options depending on local facilities and requirements.
Before choosing leveling or replacement, ask a qualified concrete contractor to assess the slab condition and the cause of movement. A smooth-looking surface alone does not establish which repair is suitable.
The Mudjacking Alternative
Mudjacking, or concrete leveling, may be an option for a sunken slab. Compare written estimates for leveling and replacement rather than assuming a fixed percentage saving. The contractor’s process typically includes:
- Drilling Holes: The contractor drills small holes in the concrete slab.
- Pumping Slurry: A mixture, typically made of ground stone or cement slurry, is pumped under the slab.
- Re-leveling: The pressure raises the concrete back into position.
- Filling Voids: Additional holes are used to fill any remaining voids beneath the slab.
- Patching: A concrete mix is applied to patch the holes flush with the surface for a smooth finish.
