Decision Guide
How each lifting method works, where they really differ, how Phoenix clay and storm water affect the choice, and the cases where lifting isn't the answer at all.
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Short answerBoth lift a sound, settled concrete panel by pumping material under it. Mudjacking uses a heavy cement slurry through larger holes and suits wide voids on firm ground. Polyjacking injects a light, expanding foam through smaller holes, cures fast and adds little weight to soft soil. Neither repairs a broken panel or stops water washing out the base.
Mudjacking vs polyjacking is a choice between two ways of doing the same job: raising a concrete panel that has settled, and filling the empty space under it so it stays up. Both drill through the slab and pump material underneath. They differ in what that material is, how much it weighs, how big the holes are and how fast the slab can be used again. Sundial Driveway Repair is a service company offering and managing concrete driveway leveling and sunken driveway repair across Phoenix and its suburbs, fulfilled by licensed and insured contractors, and this guide explains how to choose between the methods. Prices for both are on the driveway leveling cost guide.
Mudjacking, also called slabjacking, pumps a cement-based slurry under the slab. Holes are drilled through the settled panel in a pattern, and a pump forces a wet mix of cement, sand or soil and water through them. The slurry first fills the void, the empty pocket left where soil washed out or compressed, then builds pressure under the slab and lifts it. The operator works hole to hole, raising the panel in small steps until it lines up with its neighbors. The holes are then patched with grout.
Its strengths are filling and bulk. A large void, such as the space left along an edge after a monsoon washout, takes a lot of material, and slurry is a cheap way to fill it. Once hardened, it forms a solid bed under the slab.
Polyjacking, also called foam lifting or polyurethane leveling, injects a two-part polyurethane through smaller holes. The two liquids mix in the injection gun and expand into a rigid foam as they react, filling the void and pushing the slab up. The expansion is quick, so the slab rises in short, controlled bursts. The foam cures within a short time, and the slab can usually take traffic sooner than with slurry. The holes are patched the same way.
Its strengths are weight and speed. The cured foam is light, so it adds very little load to the soil under it, and it doesn’t absorb water once cured.
| Mudjacking | Polyjacking | |
|---|---|---|
| Material | Cement, sand or soil and water | Two-part polyurethane foam |
| Weight added under the slab | Heavy | Light |
| Hole size | Larger | Smaller |
| Time before heavy loads | Longer, while the slurry hardens | Shorter |
| Water | Can wash out if water keeps running under the slab | Resists water once cured, but the soil around it can still erode |
| Good fit | Large voids on firm ground | Weak or soft soil, and drives needed back in use soon |
| Price | See the leveling cost guide | See the leveling cost guide |
Weight is the difference that matters most on weak ground. If a slab sank because the soil under it was soft or poorly compacted, adding a heavy slurry bed puts more load on the same soil. Foam adds almost none. On firm ground with a washed-out pocket, the weight matters less, and slurry fills the space well.
Control is the second. Foam expands fast, so small lifts are quick and precise; slurry lifts more gradually as pressure builds. Both depend on the operator, and neither can be pushed too hard without cracking the panel, especially a thin or already-weakened one.
Holes matter for appearance. Both leave grouted patches, but the smaller foam holes are less noticeable, which counts on stamped or colored concrete. The stamped concrete repair page covers those finishes.
The method matters less than the reason the slab dropped, and in the Valley soil and water are the first things to check.
Clay that shrinks and swells. USDA soil survey samples show moderate or higher shrink-swell soil at 78.4% of sampled points in Gilbert, 76.9% in Chandler and 61.4% in Tempe. A slab on that clay drops when the ground dries and rises when it wets. Lifting a panel that settled during a dry stretch can leave it too high once the soil takes on water again, so the timing and the cause both need thought. Neither slurry nor foam stops clay from moving; only keeping the moisture around the slab steady does.
Water washing out the base. Sky Harbor averages only 7.22 inches of rain a year, yet about 4.1 days a year bring half an inch or more (NOAA climate normals), and storm water running off roofs and hard ground can carry base material out from under a driveway edge in one season. Downspouts, sprinkler heads and flood irrigation do the same more slowly. If the water isn’t redirected, it erodes the soil next to whatever fill is pumped in, and the panel settles again. Driveway drainage covers the fixes, and the guide to driveway sinking after heavy rain covers the warning signs.
Caliche. Where a cemented layer sits close under the base, a slab tends to settle over the softer pockets beside it rather than evenly. The caliche guide explains how that shapes a repair.
Lifting is the wrong repair in several situations:
In those cases the honest choice is a new section on a rebuilt base, and the repair vs replacement guide covers how that decision is made. Where a sunken panel has only left a small lip at a joint, trip hazard grinding may be all it needs.
The visit looks at the whole drive, including where water runs and the transitions at the garage, sidewalk and street. Panels are checked for cracks that cross them, and hollow spots are found by tapping, which shows how big the void is. The estimate names the method and the area and says what it excludes. If the visit finds soft base, it explains how that changes the scope, which is often where foam’s lighter weight earns its place.
Ask any estimate three questions: why did this slab settle, what will stop it settling again, and why this material for this ground. The guide to why driveways crack and sink gives the background to judge the answers. When you’re ready, call the number at the top of this page or send photos for an estimate.
It can last a long time when the cause of the settling has stopped, such as base that was poorly compacted and has since consolidated. It won't last if the cause is still active. Water running under an edge can wash slurry and soil out again, and clay that keeps wetting and drying keeps moving the slab. The lift is only as lasting as the drainage fix that goes with it.
Foam usually does. Polyurethane cures within a short time, so a lifted panel can often take a car again soon after the work. Cement slurry needs time to harden before heavy loads, so the wait is longer. Either way, the drilled holes are patched and the patch material needs its own short cure, and the estimate should state how long to keep vehicles off.
Yes, a little. The holes are patched with cement grout after lifting, and the patches are visible as small circles, more so on colored or stamped concrete. Foam needs smaller holes than slurry, so the patches are smaller. Neither method changes the color of the slab, and the estimate should say how the holes will be finished.
Tell us the surface, what changed and the nearest cross streets. Photos of the damage and the street edge make the estimate more useful.
Concrete driveway leveling in Phoenix: when a settled panel can be lifted, mudjacking vs foam, what lifting can't fix, and local price ranges.
What mudjacking and polyurethane foam lifting cost per square foot, why small jobs price as a minimum, what drainage and joint work add, and where lifting stops being the cheaper choice.
What a monsoon storm does to the layers under a driveway, how to tell a washed-out base from a slab that is only cracked, and which repairs hold once the water is dealt with.
How a driveway is built, what the Valley's heat, soils and storms do to each layer, how to read the cracks you can see, and when a repair can wait.
The signs that point to a repair, the ones that point to a new driveway, the middle option of replacing sections, and the Phoenix soil, water and right-of-way rules that tip the choice.
Roots are one cause to check where a large tree grows near the drive, not one to assume. Here is how they do damage, how to confirm them, and which repairs fit.