A good slump height really depends on the project, but there is a use for nearly all slump levels. For example, low slumps are best in projects that require structure, such as curbs and roads. High slumps often require additional reinforcement, but they flow more freely into hard-to-reach spaces.

Polyjacking can be a permanent solution to sunken concrete if you also address the underlying issue—like poor drainage—at the same time. The polyurethane material itself can last as long as or even outlast the concrete you’re lifting it with. Your sunken concrete issue will likely return if you don’t couple polyjacking with proper drainage to prevent future soil movement and sinking.

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.

Many contractors offer warranties for their work. Confirm terms before starting the project.