Concrete curb ramp work in progress during an accessibility upgrade

MUDJACKING VS. POLYJACKING

Mudjacking vs. Polyjacking: Mud or Foam?

Both fill the void and lift the slab. Mud is cheaper and heavier, and the holes are bigger. Foam is lighter, leaves ⅝ in. holes and is ready the same day. Choose by the slab, not the sales pitch.

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Photo: Oregon DOT / Wikimedia Commons · License

METHOD 1 · MUDJACKING

Bigger holes, heavier fill, lower price.

01Find the void
Soil under the low end washed out or packed down. The slab is hanging over an empty pocket and has tipped into it.
02Drill 1–2 in. holes
The crew drills a pattern of holes about the size of a quarter to a half-dollar through the low section.
03Pump the slurry
A cement, sand, and soil slurry is pumped under pressure. It fills the void first, then pushes the slab up.
04Patch and use it
Holes are packed with grout. Plan on about 24 hours before driving on it.

Slurry is heavy, about 100 lb per cubic foot, and fills big voids cheaply.

METHOD 2 · POLYJACKING

Smaller holes, lighter fill, same-day use.

01Find the void
Soil under the low end washed out or packed down. The slab is hanging over an empty pocket and has tipped into it.
02Drill ⅝ in. holes
The crew drills a few pencil-sized holes, about the size of a dime, through the low section.
03Inject the foam
Two-part polyurethane is injected. It expands to fill the void within seconds and pushes the slab up.
04Patch and use it
Holes are capped with cement patch. Foam cures in about 15 minutes, so you can usually drive on it the same day.

Foam weighs about 2–4 lb per cubic foot, so it adds almost no load to weak soil.

BEFORE / AFTER

What the crew is actually fixing.

Sidewalk panels that dropped below the curb and the next slab, leaving a raised edge — **Trip edge, water pooling.** One end sank into a washed-out pocket. Panels no longer line up and rain runs the wrong way.

Technician injecting polyurethane foam through a slab while a dial gauge on the next panel tracks the lift — **Lift while watching a gauge.** The tech injects through the slab while a dial indicator on the next panel shows exactly when it’s level.

After

Flush joints, drainage restored. The void is filled, the slab sits back at grade, and the holes are patched. Same concrete, no tear-out.

Photos: credits & licenses. Diagrams are illustrations, not to scale.

NATIONAL PRICE CONTEXT

Compare scope—not just price

Mudjacking runs $4–$9 per sq. ft. and foam runs $8–$25. Pay for foam if you need to use it the same day, have soft soil, or want small holes on a slab people will see. Go with mud if it’s a big void and the budget matters.

These are national reference figures, not local market data, a guarantee, or a substitute for a written estimate after an on-site inspection.

Compare the methods

A good quote names the panels, the material, the hole layout and what’s not included. If it just says “level driveway, $1,800,” ask for the rest in writing.

Factor	National reference / question
Material	Cement-based slurry vs. polyurethane foam
Typical national cost	$4–$9/sq. ft. mudjacking · $8–$25/sq. ft. polyjacking
Access holes	Mudjacking holes are typically larger than foam-injection holes
Stone-slurry grout	A separate option; HomeGuide lists $6–$15 per sq. ft.
Ask about	Slab condition, drainage, lift plan, curing guidance, and warranty

Questions to bring to a quote

What may be causing this section to settle, and how will you assess the area below it?
Which lifting method and material do you recommend for this slab—and why?
How will you handle drainage, nearby panels, cracks, or access limitations?
What is included in the written price, and what could add cost?
What curing, use, and maintenance guidance should I follow?
What warranty applies, and what conditions are excluded?

SOURCE NOTES

National ranges, linked to their source.

Cost figures were checked against these HomeGuide pages. Estimates are broad national ranges and may change over time.