Mark out the corners of the area you will excavate for the storage building foundation. Drive sharpened pegs at the corners. Measure diagonally from corner to corner, if the dimensions are the same, the corners are square. Adjust, as necessary.
Dig the area inside the stakes to a depth of 2 inches and set the removed soil aside for use elsewhere in the yard or garden. Continue excavating the soil until you remove the soil to a depth of 3 inches over the entire area. Lay a level on a 2-by-4 inch piece of lumber to check for level across the bottom of the excavated area.
Place treated lumber around all four inside perimeters of the excavated area. Secure the lumber in place with pins or stakes. Place a layer of landscape fabric covering the soil from edge to edge. The landscape fabric ensures proper drainage and prevents grass and weeds from growing.
Fill the excavated area with mixed-sized crushed stone. This type of stone is easier to compact than gravel or stone that is all the same size. Rake the stone into place until it is level. Tamp the stone with a manual or motorized tamper, periodically checking for level. Add or remove stone as needed until the stone platform is level with the surrounding lawn.
Space 4-by-4-inch treated timbers for the base of the storage shed to rest on. The instructions furnished with the shed kit will recommend how many and the spacing. The timbers will run the opposite way that the floor joists in the shed kit run.
Things You Will Need
- Tape measure
- Treated lumber
- Landscape fabric
- Crushed stone
- 4-by-4 inch treated timbers
- A motorized tamper will tamp the stone in place easier and faster than a hand tamper.