Concrete makes a terrific base for patios. It's good-looking and resilient to damage from weather and wear and tear. A concrete pad is relatively simple to install by just one or two people. Further, it won't shift around like patio bricks or pavers or rot like wood; it adds long-term value to your home as well as giving you a great place to entertain friends and family.
Plan your patio well. Once you pour your concrete pad it is permanent. Check your local planning office for restrictions or requirements. Get a planning consent for your project.
Mark the perimeter of your patio and dig out the area at least 30 cm (1 foot) deep with a shovel; allow an extra 10 cm (4 inches) around all sides for bracing that will be removed once the slab is finished.
Plant 5 cm x 10 cm (2 x 4 inches) wood around the perimeter. Build your frame up to ground level using as many beams as needed to reach that level. Use wood stakes to secure the framework. Use a level to ensure that your frame is level so the top of your concrete pad will be even.
Shovel gravel into the base of your patio at least 20 cm (8 inches) thick. Smooth it out with a rake for a level surface.
Mix concrete according to the directions on the bag. For smaller projects the concrete can be mixed in a large bucket or wheelbarrow. For larger projects a mixer is a worthwhile investment.
Pour concrete at least 10 cm (4 inches) thick. The thicker your pad the more stable it will be but for light foot traffic, 10 cm (4 inches) is a minimum. Laying a mesh or rebar inside the concrete as you pour helps strengthen large patio pads. In order to lay a mesh strengthener pour half the concrete, lay the mesh on top of that layer and then pour the remaining concrete over the mesh. Use a level to make sure the surface of your concrete is even.
Smooth the top of the concrete with a trowel or the edge of a beam.
Let concrete dry completely before walking on it. To prevent cracking or buckling while drying, keep the surface of the concrete misted while it dries. Use a hose nozzle set on fine mist to lightly wet the surface at least every six hours during the drying period.
Remove framework. Back-fill the edges of the ditch with dirt.
Don't pour concrete on an extremely hot day over 26.7 degrees C (80 F) for the best results. Temperatures over 26.7 degrees C (80 F) will dry the concrete too quickly and can cause cracks or buckling. To keep your concrete pad looking its best and prevent stains, seal it with a concrete sealer after it has set for the appropriate amount of time. If you desire a concrete pad that is not the traditional concrete colour, you can add concrete colour to the mixture before you pour it to give it a unique appearance. If you add colour to your concrete mix, it is important to mix all of the concrete you will be using at once to ensure a uniform colour throughout the project.