Mudjacking vs. Polyjacking: An Honest Comparison
Both lift sunken concrete. The right choice depends on what is under your slab — here is how the decision actually gets made.
Get My Free EstimateThe short version
Mudjacking (slurry)
A sand, soil and cement slurry pumped through holes roughly an inch wide. Heavier, cheaper per cubic foot, excellent at filling large voids economically. Cures over hours.
Polyjacking (foam)
Two-part polyurethane injected through holes the size of a bottle cap. Expands in seconds, cures in minutes, adds very little weight. Costs more per job.
How the choice gets made on a Milwaukee slab
The deciding question is what the slab is sitting on and how much space needs filling.
Large washout cavities favor slurry. Filling a big void with foam is expensive because you are paying for chemistry by volume. Slurry fills the same space for less, which is why it remains the workhorse for older driveways and aprons where water has been running under the concrete for years.
Weak or saturated sub-base favors foam. Slurry is heavy. If the material under your slab is already struggling — soft lakebed clay, saturated fill, a garage floor over poorly compacted backfill — adding weight can start the next settlement cycle. Foam weighs a fraction as much and spreads load rather than adding to it.
Finish-sensitive surfaces favor foam. The injection holes are much smaller and patch nearly invisibly, which matters on a stamped patio, a newer decorative drive, or an interior floor you plan to coat.
Speed favors foam. Foam is drivable in under an hour. Slurry generally wants the rest of the day. On a single-car drive that is the difference between parking at home tonight and parking on the street.
What does not decide it
Foam is not "the modern one" and mud is not "the old one" — both are current, both are used by serious contractors, and a company that only offers one will always recommend that one. Permanence is not the differentiator either. Neither method stops water. If the downspout that hollowed out your slab still dumps against the apron, the void comes back regardless of what filled it, which is why grading and joint sealing are part of doing the job properly.
Milwaukee's freeze-thaw cycle is hard on both methods equally. Frost here drives down several feet, and slabs move seasonally no matter what is beneath them. What the lift does is remove the void that lets the slab drop past level and stay there.
Common questions
Which is better for a garage floor?
Usually foam. Interior slabs sit on backfill that is often the least compacted soil on the property, the holes patch cleaner on a floor you actually look at, and the low added weight matters when the base is already suspect.
Will I see the holes afterward?
Slurry holes are about an inch across and get patched with grout; visible if you look, unremarkable from standing height. Foam holes are considerably smaller and nearly disappear once patched.
Does foam last longer than mud?
Neither fails from age when the void is properly filled. What ends a lift early is water still getting underneath. Fix the drainage and seal the joints and both methods hold for years.
Can you use both on one property?
Yes, and it is common — slurry on the big driveway void, foam on the garage floor or the stamped patio.
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