Professional roofing estimators have to come up with estimates fast. But even if you do only an occasional roof, you can cut down your bidding time by borrowing some of their estimating techniques. With these, you won't have to climb on the roof to get an accurate waste-free estimate. You do all your measuring and calculating from the ground. This system is based on measuring the building's "footprint" and converting it to a "roofprint" by using factors for slope and pitch. You gauge slope and pitch from the ground, as well, either by direct measurement or by using special measuring jigs. You'll only need simple math. But make sure your measurements are accurate. The easiest way to keep track of