How to Measure & Build a Cement Patio

Measure the distance and place a stake at each corner of the patio plan, once you've decided on size and shape. Place the stakes approximately 3 inches outside of the planned patio border so you have room for forms. For square patios, measure from corner to corner. The distance should be the same. If it's not, adjust the stakes as needed.

Excavate the patio area. Dig 6 to 8 inches, depending on how thick you want the patio slab to be. You need 4 inches for gravel to drain water away from the patio. If you want a 4 inch patio slab that's ground level, dig 8 inches.

Wrap twine around the stakes and check the slope. The ground should slope 1/4 inch for every foot of patio, sloping away from your home. Add or remove dirt as needed to achieve that slope.

Build your mold using 2-by-8s. Screw the 2-by-8s together using wood screws and a drill and set it in place. Check the grade to make sure it remains correct.

Add plenty of braces to the frame. Use scrap lumber and drive it into the ground on one end and screw it into the frame on the other. Place several braces on all sides of the patio form. This helps the form keep it's shape when filled with heavy, wet cement.

Lay 4 inches of pea gravel. Rake it evenly across the excavated area and check to make sure you've maintained the sloped grade.

Lay a layer of wire mesh over the top of the pea gravel. Shim the wire mesh with scrap lumber to lift it so it's at the mid-point of the cement slab. The wire strengthens the cement.

Pour cement into the form. For larger patios, stand in the form and push the cement to one side until it's full. Step back and continue. Use a long piece of scrap lumber and slide it across the top of the form, keeping the cement at the proper height. Strike the sides of the form firmly and frequently to remove air bubbles.

Smooth the surface of the cement with a float, which is a large, flat trowel.

Finish the cement by drawing a broom over the top, leaving thin marks in the cement so the surface isn't slippery.

Edge the cement by running a thin trowel around the perimeter, leaving a smooth border around the cement patio.

Add expansion joints. Use a trowel with a notch and cut a line into the cement that's 1/4 the thickness of the cement. Lay a long scrap of wood down and use it as a guide. Press the trowel into the cement and pull it down the length of the wood. Cut an expansion joint every 4 to 5 feet in both directions.

Cover the patio with strong plastic to trap the moisture in the cement, slowing the curing process. Leave the patio covered for seven days. Wait a month before removing the forms and backfill around the patio. Plant new seed or lay new sod.