How to Pour a Concrete Slab Foundation

Prepare the location by outlining the site with landscape paint. Dig out the sod and continue digging to remove 8 inches of soil. Level the floor of the expanse by digging out any high areas.

Go over the bottom of the expanse with a compactor to push out air bubbles and moisture from the soil so it doesn't shift beneath the foundation.

Dump a 4-inch bed of highway gravel into the expanse and drag a board over the surface to spread it evenly. Compact the surface of the gravel to improve the area's drainage and provide a strong base for the concrete.

Lay wire mesh over the gravel as reinforcement for the concrete.

Arrange 2-by-4-inch boards along the interior walls of the expanse, positioned vertically. The boards will serve as forms, holding the shape of the concrete until it hardens. Remove the boards once the concrete dries.

Brace the form boards with 1-by-3-inch garden stakes. Hammer them into the ground every 3 feet around the exterior of the boards.

Mix the concrete in a wheelbarrow with concrete mix and water.

Tip the wheelbarrow onto the site and shovel out the concrete into the corners and evenly over the surface. Work methodically from one side to the other until the concrete is level with the form boards.

Position a screed or 2-by-4 over the concrete and drag it across to level it. Smooth the surface with a trowel or floater.

Score a ½-inch deep grid of control joints every 3 to 4 square feet with the edge of the trowel. Position a 2-by-4 over the surface and drag the trowel along it so the lines are straight.

Lay wet burlap or canvas over the concrete for one week to cure the concrete slowly, wetting the material twice a day.