Concrete patios are great places to relax. They can be built as a garden addition immediately outside your patio doors or laid as an extra feature to your outdoor pool. Here are the steps to mixing and pouring concrete patios.
Step One - Preparing the Ground
Make the concrete patio outline using stakes and string. You will need to make the outline 3 inches larger than the patio will ulitmately be to allow for the forms. The patio should slope slightly away from the house to drain. Take off the area of turf within the outline and dig down 4 inches. Tamp down the earth so it becomes firm. Use vegetation killer on the bare earth to remove any unwanted weeds. Where the patio meets the foundation, lay down the expansion strips.
To build the forms for the patio, pound in small stakes every 3 feet and add 2x2 lumber to create the form. The top of the lumber should be at the same level as the grass. Keep the strings up to help you check the level of the form and remove once the forms are installed. Fill the form to a level of 2 inches with crushed rock for drainage, tamp down and lay wire mesh on top. This will help strengthen the concrete in the patio.
Step Two - Mixing the Concrete
For an area the size of the average concrete patio, you’ll need to rent a concrete mixer. Mix one part Portland cement, two parts sand and three parts aggregate in the mixer. Add just enough water to ensure the mixture is workable. Use your shovel help stir it in the mixer. You will need several loads, as the average 50 square foot patio will usually require about 25 bags of cement.
Don’t mix too much at one time or you’ll need to keep adding water, which will thin the concrete. Remove the concrete from the mixer with the shovel to pour into the form.
Step Three - Laying the Concrete
Pour the concrete into the form and smooth out with a piece of 2x4 lumber. Work area by area, covering 3 or 4 feet at a time. This is called striking. Once you’ve finished the striking, start using the float. This will help push the concrete down into the aggregate. Once water bleeds through onto the surface, stop using the float.
Now use the edger to create an attractive edge, drawing it around the outside of the concrete slab. To help make sure the slab doesn't crack, use a tool groove to create control joints in the concrete approximately 5 feet apart. To give a skid proof surface to the patio, use a trowel and pass lightly over the surface of the concrete.
Step Four - Curing the Patio
Once you’ve finished with the tools, you still need to let the patio cure. You don’t want this to happen too quickly, so cover the concrete with a sheet of polyethylene and leave for a week.
After a week, remove the polyethylene and the forms. To finish the concrete patio, fill in the area where the forms were set using the dirt you dug out earlier.