Traditional mudjacking in Northern Colorado since 2003 · 20,000+ slabs lifted
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Resources / Mudjacking vs foam
We are a mudjacking company. You should read this knowing that, and you should also know we are going to tell you where foam is the better answer.
Both lift a settled slab by injecting material underneath it through holes drilled in the concrete. Both fill the void that opened up under the slab. The difference is what goes in the hole, and that difference has real consequences for cost, appearance, cure time and what the slab can carry afterwards.
The marketing around this is unusually one sided. Foam contractors have a well funded story about lighter material and smaller holes, and much of it is accurate. What tends to be missing is the other half: where dense material does better, and what you are giving up for those smaller holes.
Here is the comparison as straight as we can put it.
Factor
Mudjacking
Polyurethane foam
Material
A cementitious slurry of sand, soil and cement, pumped wet. Dense, and close in nature to the ground the slab was already sitting on.
A two part expanding polymer that reacts and cures in place. Lightweight and closed cell once set.
Injection holes
Larger. Patched flush after the lift, and visible up close on a smooth or decorative surface.
Smaller, typically penny sized. This is a genuine advantage and it is the one foam companies lead with.
Weight added
Heavier. On genuinely weak soil that extra weight is a fair concern and worth discussing.
Much lighter, which is the main argument for using it over unstable or low bearing soil.
Filling large voids
Fills with volume and weight, which suits washed out base and open cavities under a slab.
Expands to fill, and some systems inject deeper to stabilize loose soil below the slab.
Cure and return to use
Foot traffic quickly. Vehicles and heavy loads after a cure period we tell you before starting.
Cures in minutes. Same day use is a real and meaningful strength of the method.
Heavy and repeated loads
Dense material supports vehicle, equipment and truck loading well, which is why we favor it on driveways and shop floors.
Rated foam products carry substantial load too. Performance depends heavily on the density of the specific product used.
Water exposure
Cementitious material can be eroded by moving water, so drainage still has to be addressed.
Closed cell foam does not absorb water, which is a fair advantage in consistently wet conditions.
Cost
Generally the lower cost option for the same slab, and materially cheaper than replacement either way.
Usually the higher cost option, reflecting the material and the equipment involved.
Tight interior spaces
Workable, but the hose and mixing setup need access.
Smaller equipment footprint can be an advantage in confined interior work.
"Foam lasts longer than mudjacking"
Neither material fails on a schedule. What causes a repeat is an unfilled void or an unaddressed cause, usually water still moving soil out from under the slab. A well filled mudjacking job with the drainage sorted outlasts a poorly executed foam job, and the reverse is equally true. Ask either contractor how they will fill the void and what they think caused the settlement. The answer to that tells you more than the material does.
"Mudjacking is too heavy and will sink again"
On genuinely weak soil this is a legitimate concern and we would tell you so. On the ordinary compacted fill and clay under most Northern Colorado driveways, the added weight is small relative to the concrete already sitting there. It is a real consideration in specific conditions, not a universal disqualifier.
"The holes are barely noticeable"
Foam holes are genuinely smaller. Ours are genuinely larger and you will be able to find them up close after patching. Anyone telling you their patches are invisible is overselling, whichever material they use. Look at photographs of finished work before you decide.
"Concrete lifting is always cheaper than replacement"
Almost always, and by a wide margin. The exception is a slab too deteriorated to lift, where the money spent trying is wasted and replacement was the answer from the start. That is a judgment about the condition of your concrete, and it should be made honestly at the estimate.
These work on us as well as on a foam contractor. If a company cannot answer them clearly, that tells you something.
If the answer does not mention water, drainage or fill, they have not looked properly.
Filling the space is what makes a lift hold. It should not be an afterthought in the explanation.
Ask to see the pattern before drilling starts, particularly on a visible surface.
You should get a specific answer for your slab, not a general reassurance.
Get the terms in writing, including what is excluded and why.
Their own work, in your area, not supplier marketing images.
The right repair method depends on the slab, the void, the soil, the drainage, the expected load and the condition of the existing concrete. Not on whichever material happens to be in the truck.
We use traditional cementitious slurry and we think it is the right choice for most of the concrete in Northern Colorado. For some slabs it is not, and when we think that is the case we will tell you so during the estimate rather than take the job anyway.
Free on site estimate, and an honest answer even when that answer sends you to somebody else.
Most of it can. Get a free estimate and a straight answer about what your slab needs.
