There are numerous methods for the repair of settled and unstable foundations. These repair methods are most commonly referred to as Piering, Underpinning, Foundation Stabilization, and Foundation Lifting. Due to the complex nature of these types of foundation problems, the correct repair is critical. A-1 will assess your foundation and provide the best and most economical solution for your particular situation.

Step 1: Assesment -  It is imperative that you work with a foundation repair company that has experience understanding the root causes of your issues. Cracks in walls, sticking doors, etc... can have multiple causes. If your problem is not evaluated from all angles you could spend money on a fix that doesn't end up solving your problem.

Be sure the estimator spends a good amount of time walking your property, inspecting walls inside, and looking for all the possible causes of your issue. A thorough exam beforehand can save lots of time and money down the road.

Step 2: Excavation - Unfortunately, foundation repair can be a pretty invasive solution. But it is vital that your foundation repair company get to the root of the issue, and not try some bandaid fixes. Any landscaping will need to be removed (or moved) and a trench or holes will need to be dug down to your foundation's footer. But don't worry. After completion, all will be put back the way it was. And any landscaping that was moved can be returned to its original location.

Step 3: Footer Preparation - It is critical to proper sunken foundation repair that all work is done at the footer. Piers, that will be used to lift the foundation, will either be connected to the side of the footer or placed underneath, depending on the needs of the job. If the pier will be connected to the side, the footer must be prepared by cutting off any extraneous concrete to make a smooth surface for the piering bracket. If the pier will be placed under the footer, then additional excavation will be required.

Step 4: Piering Bracket Installation - If a side-mount piering system is used, then a bracket will need to be installed. This usually consists of an L shaped bracket that supports the footer from underneath, as well as heavy-duty bolts that are bolted directly to the footer with holes drilled into the concrete. 

Systems that use piers placed under footers don't require a bracket like this as the piers will be pushed against the underside of the footer.

Step 5: Pushing the Piers - After the bracket is mounted to the footer, piers (steel pipe) is pushed into the ground. This is done by mounting a bracket on the pier, then using a hydraulic cylinder to push lengths of pipe into the ground. Additional pipe is used until the pier reaches bedrock, or until sufficient pressure is built up to achieve lift on the foundation.

These piers will become the new foundation for your home. Depending on the extent of your problem this could be just one pier, or several spaced a few feet apart. This is a permanent solution and will last the life of your home.

Step 6: Lifting the Structure - Once the piers are all pushed to their required depth, the hydraulic cylinders are removed, and a series of bottle jacks are used in their place. These jacks push against the piers in the ground and pull the piering bracket, that was bolted to the house, upwards. Thereby lifting the house. This system allows precise, and gentle lifting of the house, without the danger of lifting too far. It may seem counterintuitive to think simple car jacks can lift a house, but each jack is rated to lift several tons.

Step 7: Bolting Piers to Structure - After the house is lifted back into place, the bracket is bolted to the pier. This creates a rigid, new foundation for your house that will keep it from moving for years to come.

Once all the brackets are bolted to all the piers, extraneous equipment is removed. Sometimes concrete will be poured down the piping of the piers to give it a little more strength. And a slurry can be pumped beneath the footer to fill any voids created as the foundation was lifted. Then the trench is filled in and any landscaping that was moved restored.

Step 8: Finishing Up - After the foundation has been lifted into place, you may need to repair any cracks that had developed in the foundation, brick walls, or interior walls. Oftentimes your foundation repair company can handle repairs to cracks in your foundation or any tuck-pointing (repair of the mortar) in your brick walls. With the right repair, these cracks should not reappear.