How to Pour a Basement Footer

Speak to a building inspector to find out the depth required for placing your footers. They’ll need to be lower than the frost layer, so the minimal depth will vary based on where you’re building your basement.

Rent a backhoe, and use it to dig out the hole for your basement. Dig the foundation square and additional 5-feet around the perimeter to allow room to dig the footer space. You can rent backhoes from an equipment rental shop.

Mark the edge of your basement with lawn flags placed in the ground about 5 feet apart. You can keep the flags running straight by using a laser level to point between the foundation corners, and planting the flag along the laser line.

Dig the footer 30 inches wide to the required depth, using the basement foundation perimeter as the centerline of your footer. This way the footer will extend 15 inches to either side of your basement walls. You may need to modify the width of the footer according to your wall width because it needs to be at least twice the thickness of the wall it supports.

Tamp down the base of the footer to give the concrete a firm foundation on which to cure.

Place parallel lines of rebar support chairs down the length of the footer, spacing them 1 foot apart both between the parallel rows and between each chair in a row. Lay a row of rebar over each of the lines of chairs. Use rebar with a 90-degree curve for the corners of the footer to keep the lines continuous around the perimeter. Overlap the bars if needed to make the length of the footer by about 3 inches and tie the overlaps together with metal rebar ties, using a pair of pliers to tighten the ties around the bars. You’ll also need to tie the 90-degree curved bars to the straight ones for each line. Use a hydraulic bolt cutter to cut the rebar when needed.

Build your foundation form over the footer before you begin to pour the footer.

Use a cement mixer to mix the concrete for the footer. Add the dry mix to the mixer, and then pour in half of the needed water. The instructions for the concrete will give you the ratio of mix to water required by that specific manufacturer. After mixing the water in with the concrete, add the rest of the water to the mix, and continue until you have a thoroughly mixed batch, with no dry areas of concrete visible.

Pour the concrete into the footer from the corner, spreading it throughout the hole using a spade until the footer is completely filled. The concrete should sit evenly with the base of the form for the floor of the basement.

Run a wood screed down the length of the footer to fill in any voids in the concrete with any high points on the footer. Leave the footer to cure overnight before pouring the basement slab.