Cost of Repairing a Concrete Foundation
- According to the Concrete Foundations Association of North America, cracking is a common complaint that consumers have about concrete. Several factors can cause cracks, including shrinkage from drying, temperature contracting, settlement of the subgrade and loads that are too heavy. Cracks that do not affect the structure of the foundation, are not leaking water and are narrower than 1/16 to 1/4 inch are acceptable and no cause for concern. Otherwise, they need professional intervention.
- Only a trained worker can determine the cause of foundation problems. Structural engineers can investigate most problems for about $500. If you suspect the ground is causing problems, such as clay that is making the foundation settle, you can have the soil tested for between $500 and $1,500. A cheaper option for determining soil composition is to contact your city government, university or library to view topographical maps of the area. You can also hire a geology student to perform testing at a low price.
- Simple repairs that require only cleaning out the concrete and patching with caulking run about $500 to $1,000 per crack. The worker can also determine if other cracks of concern have developed, since it’s unusual to have only one crack. A more expensive process is called slabjacking or mudjacking. This pumps a mix of cement, water and sand under the existing concrete to lift and level uneven foundations. This costs from $1,500 to $3,500 depending on complexity.
- More complex fixes involve piering or piling. This drives steel pilings into deeper soil to prevent foundations from sinking further. This runs from $750 to $1,500 per pier depending on the type of pile, the depth of insertion and whether hard rock or other problems exist under the foundation. Three to six piers are commonly used per crack. A more extreme repair raises the foundation by first lifting the house, excavating underneath it as needed, building or restoring the existing foundation, then placing the house back. This complicated process costs from $20,000 to $30,000.