How to achieve a 1% gradient
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.