A sinking foundation can be lifted, most often by installing piers to re-level and support the weight of the house. Depending on the cause and extent of the sinking, other methods to lift a foundation include underpinning and mudjacking. Consult a foundation repair pro to determine the best way to lift your sinking foundation. 

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.

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 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.