What Kind of Concrete to Use for Foundation Repairs?

Drilled Concrete

• This type of pier is constructed at the repair site. Special equipment is used to drill an angled hole into the soil under the foundation. Another piece of equipment is used to make the bottom of the drilled hole larger. Once complete, the drilled area should take the shape of a bell. Contractors install rebar into the hole, from top to bottom. Concrete is poured into the hole and cures over a period of approximately 14 days. Because this method only penetrates the soil to a certain depth, in some instances, the equipment may not be able to drill deep enough to pass the section of the soil that is causing your foundation problems.

Pressed Concrete

• Pressed concrete piers are constructed off-site and pressed into the soil beneath your damaged foundation. Typically, these piers are 1-foot in length and have a diameter of 4 to 6 inches. Pressed piers are laid one on top of the other until they begin to lift you foundation. These type of piers are installed using a car -- or bottle -- jack. Cables are sometimes routed through the center of the piers to strengthen and align them. The installation time of pressed piers is faster than the other methods.

Cost Comparison

• Drilled concrete piers are more expensive to install than pressed concrete. The main reason for the increased cost is the use of drilling equipment to install the concrete. Also, because this method doesn’t always fix the problem, the costs increase if the homeowner chooses to use pressed concrete in addition to drilled. Because pressed concrete piers are the cheapest of the methods used to repair foundations, it is the most commonly used.

Other Methods

• Steel piers can also be used in foundation repair. Depending on the severity of your repair, you may want to use a more effective solution that involves steel. Contractors prefer steel solutions under more extreme foundation repair conditions because they have a higher success rate using steel. Mud jacking is also a common solution to foundation failures.