How to Frame a Concrete Patio

Patios are fun

Installing a concrete patio is a moderately easy task, and can add value and utility to your home. The project has two parts. The first part is framing the patio, which is a moderately simple task. The second part involves the actual pouring, placement and finishing of the concrete. Concrete finishing is as much an art as a trade skill, so you are advised to seek out experienced finishers for the final finishing work on your patio.

Things You'll Need

• Two-by-eight or two-by-six nominal S4S (sanded on four sides) form lumber
• One-by-two precut foundation stakes, 24 inches
• One-by-two random board
• ½-inch rebar tie wire
• 8d duplex ("doubleheader") form nails
• 16d duplex ("doubleheader") form nails
• Gypsum layout chalk
• Mason's twine
• Square blade shovel
• 5 or 10-lb. sledge
• Electrical circular saw
• 16 oz. hammer
• Level or leveling device
• Square

Instructions

Grade Soil

1. 

   Dig Footings

   Level the soil. The soil must be solid enough to support the weight of the concrete. Grade the patio area to a level 4 1/2 inches below the finish slab height at the house. The soil should be graded to allow about 1/4 inch to the foot (1 percent) fall-away from the house on the final concrete surface for water drainage.

2. 

   Build Forms

   Mark out the perimeter of the slab, including the side against the house, using your twine and chalk. Using the square blade shovel, dig 12-inch by 6-inch footings at all edges of the slab to prevent edge breakage.

3. 

   Set Forms

   Nail together the two-by-eight boards to form a box around the perimeter. Line up the inside face of the form with your layout twine, which should be placed on batter board or offset stakes (see picture above). Drive one-by-two stakes vertically behind the form boards at each corner and every 4 feet using the twine to keep the boards straight.

4. 

   Brace Forms

   Set your layout twine with a 1 percent fall-away from the building. Then nail your forms to the stakes at the twine level. This will provide the necessary drainage.

5. Drive one-by-two stakes at a 45-degree angle behind the form board at each corner, each splice of boards and every four feet using the twine to keep the boards straight. Place temporary kicker stakes inside the forms to keep the forms braced until the concrete is poured. Place 1/2 inch of rebar top and bottom in the perimeter footing hung off the form boards on tie wire.

Tips & Warnings

• Small patio forms can be framed as a single unit and set in place and level with a handle level.

• Patios are subject to cracking. The best practice is to place sand below the slab, deepen the edges for "mini-footings" and place reinforcing steel in the footings and in mats in the slab itself. Check with your local building department for special requirements and for information regarding soil conditions.

References

• American Concrete Institute

Resources

• FHA Minimum Property Standards