Currently preparing an area in our garden to lay a paved patio area and pergola (the latter being provided by a professional).
My wife and I need to build a supporting wall around the sides and at the top side (see the photo below).
We have been advised to create a 1% incline on the slabs, so that water can run off when it rains etc.
My question(s) is, how do you measure out/figure out how to do this? Is this a requirement when building a patio area? Is 1% the ideal incline?
Best Answer
You want the grade to be in the width, not the overall length of the patio. The fall should point in the direction away from the home. .01 × (width of the patio in inches) = the height difference. I/E: If the patio is 8' wide, 96 inches x .01 = .96 inches. So the height of one side needs to be one inch higher than the other.
To my knowledge there is no building code for fall requirements on a patio. 1% is a very shallow fall. I would grade it at 2% (1/4" per foot) for a better fall without it looking weird to the eye. 2" over an 8' span isn't going to be very noticeable.