Sidewalks rarely sink overnight. Most settle slowly over time due to shifting soil, erosion, or water intrusion—often going unnoticed until someone trips or puddles start forming. At KC Pier, we regularly help homeowners decide whether their uneven sidewalk can be lifted with polyjacking or if it’s time for full replacement. In this post, we’ll walk through the key signs to look for and explain when polyjacking is the most effective option.
Signs That Sidewalk Damage Needs Immediate Attention
Sunken or Uneven Sections
If one or more parts of your sidewalk sit lower than the rest, it’s usually due to shifting or compacted soil. These uneven slabs don’t just hurt curb appeal; they present a real trip hazard, especially for children, older adults, and visitors.
What we recommend: If the concrete is still structurally sound, lifting it with polyurethane foam is often quicker and more affordable than replacing the slab.
Cracks Forming Across the Slab
Cracks along or across a concrete slab can result from pressure created by moving soil or water buildup underneath. These can widen over time, leading to further instability or even breakage if left unaddressed.
What we recommend: Polyjacking is ideal when cracking is caused by minor soil movement. It reinforces the area underneath and stops the problem from getting worse.
Water Pooling on the Surface
After a rainstorm, you might notice puddles collecting where the concrete once drained properly. That’s a clear sign something has shifted below the slab, changing the slope and preventing proper runoff.
What we recommend: Re-leveling the affected section restores drainage and helps prevent additional erosion that can make the situation worse.
Gaps Between Slabs or Edges Pulling Away
Gaps forming between sidewalk sections or between the concrete and adjacent structures often mean the soil beneath is settling or washing out. These spaces let in more moisture, which only accelerates the problem.
What we recommend: This is a case where we often recommend polyjacking, as it can fill the voids, lift the concrete, and stabilize the area below the surface.
Misaligned Slabs or Noticeable Trip Hazards
A noticeable height difference between adjoining sidewalk slabs is a major red flag. Even a small step between panels is enough to create a liability concern.
What we recommend: In most cases, this is an excellent situation for foam lifting. It allows for a highly controlled adjustment that brings the lower panel back in line.
Can Polyjacking Fix Your Sinking Sidewalk?
We’re often asked if polyjacking is the best fix for settled sidewalks. When the concrete itself is intact but no longer level due to shifting soil or erosion, this method is one of the fastest, least disruptive solutions available. The foam expands underneath the slab to fill voids and lift the concrete into place, usually within hours.
If you’re wondering if polyjacking can fix your sinking sidewalk in your specific case, the best way to know is with a site evaluation. We look for signs of structural integrity, determine the cause of settling, and assess whether the slab can be lifted without damage. If so, foam injection is almost always a more cost-effective and longer-lasting alternative to a full tear-out.
When It Might Not Be the Right Option
There are a few exceptions where we’ll suggest a different path:
- Heavily cracked or crumbling concrete may need full replacement.
- Tree root damage must be addressed before any slab lifting can be done.
- Drainage issues caused by poor landscape grading should be corrected before polyjacking to avoid future washout.
Need a Professional Opinion?
We’ve helped hundreds of homeowners restore sunken sidewalks throughout Kansas City. If you’ve noticed cracked slabs, pooling water, or trip hazards around your sidewalk, now is the time to act before the damage worsens. Contact us at KC Pier today for a free evaluation. We’ll help you determine whether polyjacking is the right solution and walk you through the next steps.