Polyjacking and mudjacking can both be effective solutions for sinking concrete, but they have key differences. Polyjacking, which uses expanding polyurethane foam, is often considered a better option because the foam is significantly lighter than the cementitious material used for mudjacking. This reduced weight puts less pressure on the underlying soil and lowers the risk of future sinking. Polyjacking is suitable for any sinking concrete slab, while mudjacking is typically only recommended for non-structural concrete, such as sidewalks, patios, pool decks, and driveways. The primary drawback of polyjacking is its cost, which can be up to four times higher than mudjacking—as much as $25 per square foot compared to a maximum of about $6 per square foot for mudjacking.

Most states and municipalities don’t require concrete mudjacking companies to carry a specific license, but they usually need to have a general contractor’s license, and they should be fully insured. The only exception is if the mudjacking company provides foundation repairs as well, or if it offers mudjacking for home foundations. In that case, they will typically need a foundation repair contractor’s license. You can check state requirements and then use Angi’s license lookup tool to confirm that a company is properly licensed to provide mudjacking services in your area.

Generally speaking, push piers—or steel piers—are the best option for underpinning, as they reach down to solid bedrock to find support for your foundation rather than relying on soil, which could be subject to the same issues as the soil directly below your foundation. However, the best underpinning method for your home depends on your location, how far down the bedrock is, and the type of soil in your area. Helical piers are usually the best option for sandy soil or in areas where the bedrock is too deep to use steel piers.

Most houses are expected to settle over time, but foundation sinking of more than a few inches or uneven sinking of more than an inch for every 20 feet is cause for concern. Any significant or uneven sinking should be assessed by a professional to determine the cause and perform any necessary repairs.