# Concrete Decisions

Before you can actually pour the concrete for your new concrete patio, you still need to figure out a couple of things – just how much concrete do you actually need for the job and, what is the best way to get all that concrete.

Estimating how much concrete you need

• First take careful measurements of your formed patio layout. These measurements are important because if they’re off by even 1/2 inch you could end up without enough concrete. This is also why you need to be sure your base is prepared well and the depth is the same all over. Here again, if it’s 4” deep in one place and 5” deep in another section, your estimate will be off and the patio slab itself will be prone to cracking and breaking.
• Once you’ve got your measurements, it becomes a question of using some basic math. Mixed concrete is sold by the cubic yard, usually just called a yard. This is equivalent to a space 3’ x 3’ x3’tall or 27 cubic feet.
• If your patio is 12 feet by 15 feet by 4 inches deep your concrete calculations would look like this:
• 12 x 15 x 4 = 720
• Converting to cubic feet 720/12 = 60
• Converting to cubic yards 60/27 = 2.23 cubic yards of concrete.
• Add 10% for waste and you will need 2.45 or 2.5 cubic yards for your new patio.