How to Backfill a Foundation

Add a layer of gravel over the drain tile to keep dirt from settling into the perforations of the drain tile and clogging it. Read the manufacturer's specifications that came with the drain tile to determine the depth of gravel needed. Typically, you’ll use between 8 and 12 inches of gravel.

Backfill in “lifts.” A lift is the term used for an amount of soil placed in the hole and tamped before you dump additional soil. Call your local building authority to see if there is a required backfill lift, often between 8 inches and 1 foot. If not, you’ll still get better soil stability by using the lift system.

Dump soil loosely into the hole surrounding the foundation with the front-end loader. If you’re using 1-foot lifts, dump approximately 16 inches of soil around the entire perimeter. Shovel or rake the soil evenly around the foundation.

Tamp the soil with a handheld power compactor, also called a “jumping jack.” Operate the compactor all the way around the foundation, until the soil is solid underfoot.

Repeat the dumping, leveling and tamping procedure until you reach the top of the hole, where you will fill the soil to ground level and tamp it once more.

Soak the soil with a water hose all the way around the foundation and let the water soak in. As the water saturates the soil, it will settle and sink a little more. Repeat the watering and soaking process two or three more times over the next couple of weeks.

Add the final layer of soil. The last step of backfilling is to fill in around the foundation to a minimum 2 percent grade away from the house. That creates a slope away from the home that encourages rain and gutter water to run away from the house.