How to Build a Storage Shed on Unlevel Ground

Measure out and mark the perimeter size of the shed onto the ground where you intend to build it. Place a stake into the ground at each of the corners and at 3-foot intervals between the corners.

Tie string between the stakes around the perimeter of the planned installation. Tie the string 2 inches above ground level at the stake that is at the highest point of the ground where the shed will be installed. Place a level on the strings and adjust them so that the string describes a continuous level plane around the perimeter.

Dig a 12-inch-deep, 6-by-6-inch square hole at each of the stake locations. Remove the stake as you dig each hole and then replace it into the hole, resetting the string as you're done.

Cut four 6-inch-long pieces of 1-by-6-inch lumber and nail them together to form a square form. Repeat the process to make as many forms as you have holes. Place each of the square forms at the top of each of the holes. Mark the string location on the inside of each of the forms. This is the level to which you'll fill each hole with concrete, and will ensure the tops of each of the piers are level with the others.

Mix prepackaged concrete according to manufacturer's instructions in a wheelbarrow, mixing it with a garden hoe. Pour concrete into each of the holes to the marked levels. Let the concrete set and then remove the forms. Build your shed upon this foundation.