What Is Sidewalk Leveling?
Sidewalk sections are short, independent slabs, which is exactly why they settle unevenly. When the soil under one section consolidates and the neighbouring section stays put, the joint between them becomes a vertical step. Alabama's expansive clay makes this worse, because the seasonal shrink and swell cycle works on each slab separately. This is a leveling problem, not a repair problem, and the distinction matters. The concrete itself is usually sound. What has failed is the support beneath it. Grinding the lip down removes the immediate hazard but leaves the void in place, so the section keeps dropping and the step returns. APS raises settled sidewalk sections with polyurethane foam injection. The foam fills the void that caused the settlement and lifts the slab back flush with its neighbour, so the walking surface is continuous again and the cause is addressed rather than shaved off. Where tree roots have lifted a section from below rather than allowing it to drop, the correct answer is different and APS will say so. Lifting a root-heaved slab without addressing the root simply repeats the problem, so that case is assessed on site before any work is quoted.
“A trip lip is almost always a void problem. If you only grind the lip, you have treated the symptom and left the cause under the slab.”
How APS Approaches Sidewalk Leveling
- 1
Measure the differential
We measure the height difference at each joint to establish how far each section has to travel.
- 2
Confirm the cause
We determine whether the section settled into a void or was heaved from below, because the two require different work.
- 3
Port and inject
Small ports are drilled and polyurethane foam is injected beneath the settled section in controlled lifts.
- 4
Bring flush and seal
The section is raised flush with its neighbour, then the joint is sealed and the ports patched.
When this approach is not appropriate: Sections that are cracked into multiple pieces, spalled through, or heaved by an active tree root are not candidates for lifting alone. Those are assessed separately and may need replacement or root work first.
Frequently Asked Questions
How is sidewalk leveling different from sidewalk repair?
Leveling addresses a section that has dropped, by lifting it back to grade and filling the void underneath. Repair addresses damage to the concrete itself, such as cracking, spalling or surface deterioration. APS offers both and the written estimate will state which one your sidewalk needs.
Can you level a sidewalk that a tree root lifted?
Not with lifting alone. A root heaved section has been pushed up rather than allowed to drop, so raising the neighbouring slabs or cutting the lip only postpones the problem. We assess the root on site and recommend the appropriate sequence.
How long does a sidewalk lift take?
Most residential sidewalk runs are completed in a single visit, and because the foam cures in minutes the walkway is usable as soon as the crew finishes.
Is lifting cheaper than replacing the sidewalk?
In most cases yes, and it is faster. Lifting reuses the existing concrete, so there is no demolition, no removal, and no cure time for new concrete. Where the concrete is too damaged to reuse, we will tell you replacement is the better value.