Patios - Concrete

   It may not be the world's most glamorous patio material, but concrete is practical, durable and inexpensive. The picture shows a concrete patio in cross section.
   If you want a large patio, break it into 10-foot-square or smaller modules. That way you can complete each section in a single pour.
   Separate the modules with dividers made from rot-resistant 2-by-4s. These serve both as forms for the wet concrete and as expansion joints between modules.
   For added interest you can color concrete, score it with patterns or seed it with aggregate.







Step by Step: A Concrete Patio

This patio consists of 10-foot squares separated with rot-resistant wood dividers.

1. Lay out the perimeter and height of the paving with stakes and mason's line (leveled with a line level ). To allow for proper drainage, adjust the line so that each 1-foot run of patio slopes ╝ inch away from the house or toward a French drain or catch basin .

2. Excavate for a 2-4 inch compacted pea gravel base plus a 4-inch-thick slab. Consult your local building code for prescribed thicknesses.

3. Line the perimeter with 2-by-4s and nail them to form stakes set at 3-foot intervals. The sides of the patio should follow the slope established by the mason's line.

4. Divide the patio into 10-foot squares. Lay out a grid for the wood dividers by stretching mason's line across the forms.

5. Lay the dividers on edge, flush with mason's line. Every 3 feet, nail them to stakes with 8d nails and then trim the stake tops 2 inches below tops of the dividers. Use 16d nails to fasten the 2-by-4s together at the corners. To keep dividers from popping up from the concrete, run short pieces of rebar through holes drilled in the dividers, or drive hot-dipped galvanized 16d nails into both sides.

6. Cut two 7- by 9╜-foot rectangles of 6-inch-square concrete reinforcing mesh, and lay them inside each module with the curled edges down. Extend rectangles into a 9╜-foot square at the center of each module. Support the mesh on 1╜-inch dobies so it will be centered inside the slab.

7. Pour and finish one square at a time.