What mudjacking is, and why Epp lifts with foam instead

Mudjacking: how it works and when it's the right call.

A mudjacking crew mixes a slurry of Portland cement, sand, and water on site until it reaches a thick, pourable consistency. Holes are drilled through the slab, typically one to two inches across, and spaced to reach the void underneath. The slurry is pumped through those holes under pressure, spreading beneath the slab and filling the gap left by the soil that settled or washed away. As more material goes in, the slab is gradually pushed back toward its original position. Once the slab reaches the target height, the holes are patched with a compound matched to the color of the surrounding concrete. The cement mixture needs time to dry and harden before the slab can bear weight again, so mudjacking carries a period of downtime that a homeowner has to plan around. The trade off homeowners should understand is weight. Cement slurry is a heavy material, and if a slab settled in the first place because the soil underneath was already struggling to carry its load, adding a heavy new fill on top of that same soil can work against a lasting repair rather than for one. Slurry is also a rigid material, and rigid fill in ground that continues to see freeze-thaw cycles and moisture swings can be more prone to breaking down over time than a flexible, closed-cell fill. Polyurethane foam weighs only a small fraction of what cured slurry weighs, which is one of the central reasons Epp Foundation Repair's crews use it instead. The foam is injected through much smaller ports, expands to fill the void without adding significant load to the soil, and cures fast enough that the slab is typically back in use the same day. Epp calls its polyurethane method PolyLift; the full process, including how Epp places foam mid-soil when the void profile calls for it, is covered on the polyurethane foam injection page.