How to Slope a Concrete Patio for Drainage DoItYourself.com
Step 3 - Mix and Lay Concrete. Follow the instructions on your product and mix your concrete in a wheelbarrow. If you need to add a slope to a previously built concrete platform, you should still use wooden forms, like 2x4s, in order to make sure that the concrete lays evenly. Dig out the edges alongside your patio, and pound these into place.