To frame the patio, build a grid of 3-foot squares, firmly nailed and staked at all joints and corners.

Preparing to Build a Patio

Choose the patio site carefully. Plan the patio for an area that's level and well drained, and slopes slightly away from the house. Take sun, shade, and wind into consideration.

The patio is constructed as a grid of 3-foot-square concrete units, framed by wood. Make a sketch of the yard area and plan the patio in 3-foot-square units; it can be as few or as many units as you like. When you've decided on a design, outline the patio area on the construction site with stakes and string, to give you an idea of how it looks and to mark the site. Measure accurately; be careful to keep the corners of your staking square.

When you've finalized the size and shape of the patio, excavate the entire marked-off area to a depth of about 7 inches -- 3 inches for a gravel base and 4 inches for the concrete itself. Keep the sides of the patio excavation vertical, and keep the bottom as level as possible. Then fill the entire dug-out patio area with a 3-inch-thick layer of gravel, and rake the gravel level.

To frame the patio, build a grid of 2 × 4 pressure-treated ground-contact lumber on the excavated site. You must use treated wood or the frame will rot in the finished patio; of, if you prefer, build the grid of 2 × 4 cedar or redwood stock.

Build the outside frame for the patio first, butting the 2 × 4's together at the corners; then place dividers to form the 3 × 3-foot grid, first one way and then the other. Make sure all top edges are flush; they'll be a part of the finished patio. Nail the 2 × 4's together with 8-penny galvanized common nails; check the joints with a carpenters' square as you work to be sure all joints are strong. Use at least two nails through the 2 × 4 face at each joint.

To hold the frame in place, drive 12-inch stakes all around the frame; set a stake at each corner and at each grid joint all around the frame. Cut the stakes from 1 × 3 pressure-treated ground-contact lumber, or from 1 × 3 cedar or redwood. Drive each stake carefully to hold the frame at a vertical; pound the end of the stake below the top edge of the 2 × 4 frame.

When the frame is completely assembled, check its pitch. The patio should slope evenly away from the house, about 1/4 inch for every 12 feet. Adjust the pitch as necessary, raking the gravel in the excavated area to the required slope. Fill low spots under unsupported frame members, and remove gravel as necessary to level high spots; rake to level the entire patio area to a smooth, evenly sloping pitch.

After you've framed the patio, the next step is to pour the concrete. We'll cover this on the next page.

For information on accessories for your new patio, try the following links: