DIY Concrete Patio Slab

DIY concrete patios take some time and work, but aren't too complicated.

Warm sunshine, fresh air, and the greenery and scenery of the natural world are part of the allure of an attractive patio. The patio floor is the basis of an outdoor room where you can enjoy the outdoors in comfort. Patios can be designed and constructed from a wide range of different materials, but a poured concrete slab is a solid, permanent patio material preferred by many. Install a concrete patio slab over a weekend with a few easy-to-find materials and a little work.

Things You'll Need

• White spray paint
• Tape measure
• Level
• Excavation tools
• Metal rake
• Tamper
• Hammer
• Wheelbarrow
• 4 stakes, 2 inches by 4 inches
• Piece of lumber, 2 inches by 4 inches, 6 feet in length
• 3/16-inch-thick hardboard, enough to enclose patio area to pour cement
• Trowel
• Cement float
• 10/10 welded wire mesh, 6 feet by 6 feet
• Tie wire
• 12 to 20 2-inch wire bolsters
• Concrete release agent
• Gravel to fill excavated patio area
• Concrete to fill excavated patio area
• Plastic sheeting to cover poured cement

Instructions

1. Estimate the amount of concrete you need for the area excavated. Multiply the length and width of the slab to get the total square feet, convert the thickness of the slab to feet by dividing it by 12, multiply the square footage by the thickness to get the cubic volume in feet, and divide by 27 to get the cubic yard volume. For example, 10 feet by 12 feet is 120 square feet. A 4-inch slab divided by 12 equals 0.33 feet. 120 multiplied by 0.33 equals 39.6 cubic feet, and divided by 27 equals 1.47 cubic yards. Get enough concrete for this estimate.

2. Measure the area you want for the patio, and mark it with spray paint.

3. Dig out the patio area to the depth necessary for the slab thickness you want, allowing 6 to 8 inches for the gravel sub-base and whatever thickness of slab you'd like--4, 6, or 8 inches.

4. Fill the excavated site with 6 to 8 inches of gravel and tamp it down firmly. Set the wire mesh on top of wire bolsters on top of the gravel, spaced a foot apart and tied to the wire mesh with tie wire.

5. Set up the stakes and nail or screw the hardboard to them around the tamped gravel. Spray the inside of the hardboard with cement release.

6. Mix the cement and pour it into the excavated area, tapping the sides of the hardboard to eliminate air pockets.

7. Spread and flatten the cement with the 2-by-4-inch section of lumber, then smooth the cement with the float. Finally, flatten the surface with the trowel to remove any imperfections or ridges.

8. Spray the surface of the poured cement with a spray bottle or fine-mist hose and cover with plastic sheeting. Leave overnight. Mist the slab and re-cover with plastic daily for a couple of weeks to cure the cement. Remove hardboard framing when slab is totally cured.

Tips & Warnings

• Concrete patios may require building permits in your area. Contact your municipality's building department before beginning your project to find out about zoning restrictions and construction requirements for depth of gravel, slab thickness, internal reinforcements, control joints and moisture barriers.

• Well-constructed forms and a properly prepared foundation ensure a solid and sound cement slab.

References

• "Walks, Walls & Patio Floors: Build with Brick, Stone, Pavers, Concrete, Tile and More"; Editors of Sunset Books; 2008
• "Black & Decker The Complete Guide to Patios & Walkways: Money-Saving Do-It-Yourself Projects for Improving Outdoor Living Space"; Editors of Cpi; 2010
• "Patio & Stone: A Sunset Design Guide"; Tom Wilhite; 2009
• "Patios & Walkways"; Peter Jeswald; 2010
• "Guide to Concrete: Masonry & Stucco Projects"; Phil Schmidt; 2008