There is no real alternative to underpinning, although mudjacking and polyjacking are other repair methods that can add support from underneath your foundation. Rather than placing supportive piers under your structure, these involve pumping a material under your slab to lift a sunken section back into its original position. Polyjacking, in particular, is sometimes a suitable solution for stabilization issues under slab foundations, but underpinning is often accepted as the best and most permanent solution.

Mudjacking can be an expensive foundation repair process, but in many cases, it’s well worth the investment. This is especially true if you’re lifting a portion of sunken foundation slab back into place. In that case, mudjacking can help avoid major structural damage and even home collapse by restoring the integrity of your structure with minimally invasive procedures. Mudjacking a concrete patio, walkway, or sidewalk can be worthwhile because it removes tripping hazards and makes your outdoor area more aesthetically appealing.

Mudjacking typically takes 24 to 72 hours (one to three days) to dry and cure completely before you can resume normal use. The total drying time can vary depending on the size of the project. Because the slurry mixture contains cement, it needs to harden fully to prevent the concrete slab from shifting under added weight. You should avoid walking on the concrete or placing heavy items like furniture or vehicles on the surface until it has fully set. Your concrete contractor can provide a precise timeline. As a point of comparison, if you opt for polyjacking, the polyurethane foam can dry in minutes, but it's recommended to wait about an hour before use.

The average cost for mudjacking is around $1,200, though prices can range from $300 to $3,400. On a per-square-foot basis, you can expect to pay between $3 and $8, with an average of about $5 per square foot. The final cost depends on several factors, including the square footage of the concrete, the type of slab, its accessibility, whether it is load-bearing, and the type of material used to lift it. Generally, lifting a driveway, small patio, or sidewalk is less expensive than lifting a slab foundation or garage floor.