Sunken concrete repair
When a driveway panel, sidewalk section, or patio slab drops below grade, it's not a cosmetic problem — it's a void underneath waiting to get bigger. Polyurethane foam lifts sunken slabs back to their original position by filling that void, not by pouring new concrete over the problem.
What causes it
Water moving through or under a slab gradually erodes the soil beneath it, leaving an air pocket. The slab spans the void until it can't — then drops. Polyjacking fills the void and lifts the slab back to grade in a single visit.
Most South Denver subdivisions were built on engineered fill. That fill compacts under load for years after construction, pulling away from slabs above and letting them drop. It's especially common in homes under 15 years old in Highlands Ranch, Parker, and Castle Rock.
Colorado's bentonite clay swells with moisture and contracts when dry. During dry summers the clay pulls back from beneath slabs, creating seasonal voids. Over enough cycles the slab drops permanently into those voids.
Downspouts discharging near a slab edge, poor yard grading, or a compromised gutter system all direct water under concrete. That water path erodes a channel under the slab — one that gets wider every rain until the surface above it gives way.
The process starts with small injection holes — dime-sized — drilled through the slab at strategic points above the void. Polyurethane foam is injected under controlled pressure, expanding to fill every pocket in the base material and pushing the slab back to grade from underneath.
The foam cures to full load-bearing strength in about 15 minutes. Injection holes are patched to match the surface. In most cases you can drive or walk on the repaired slab the same day.
The alternative — tearing out the sunken slab and pouring new concrete — costs 2–3× more, takes days of curing time, and leaves you with new concrete that will sink again if the void underneath isn't addressed. Polyjacking addresses the void first. That's the repair.
Every surface we lift
Polyjacking typically costs 30–50% less than tearing out and repouring. Most residential jobs — a sunken driveway panel, a dropped sidewalk section, a settled patio — run from a few hundred to a few thousand dollars depending on size and how far the slab has dropped. We provide firm written quotes after a free on-site estimate. Call (720) 767-3704 to schedule.
Often yes. The limitation isn't how far the slab has dropped — it's the condition of the concrete itself. If the slab is structurally intact (not crumbling or fractured across the panel face), polyjacking can lift it regardless of the drop distance. We assess every slab on-site before committing to a quote.
Polyjacking fills the void that caused the drop — the foam doesn't compress or wash out. If the drainage issue that created the void is corrected, the repair is permanent for the life of the slab. If water is still routing under the concrete after the lift, re-settling is possible. That's why we assess drainage on every job and offer correction work when it's warranted.
Yes — the South Denver corridor is our primary service area. Highlands Ranch, Parker, Castle Rock, Lone Tree, Castle Pines, Centennial, Greenwood Village, and surrounding Douglas and Arapahoe County communities are all on our regular schedule. Same-day estimates are typically available Monday through Saturday.