To avoid water pooling on your paving, the paved area should be slightly above the surface of the surrounding ground at all points.
When planning the slope, begin with what will be the highest point. This should be the point closest to the house or building. Place a stake at the high point and mark the height where the paving will meet the door or structure. Tie a string around the stake at that height. Place a stake (if there isn’t already one) at the outer boundary of your project. This will be your lowest point.
Attach a spirit level to your string. Tie the loose end of the string around the outer stake at the height at which the spirit level says the entire string is level. From here, move down the stake at least 1/8″ per linear foot (e.g., if it is 8 feet from your front door to the outer edge of your patio, move down the stake 1″), and draw a new line. Move the string down to this line. String crosslines down the length of the project to ensure the correct depth is marked across the entire project. If your project area has a variety of slopes, or if your design is irregular, you’ll need to repeat this process in several points. It is critical the slope is correct, so the more stakes, the better.