Generally, roofs with a ratio greater than 10% are called sloping roofs or sloping roofs. The roof slope with a single slope span of more than 9m should be taken as the structural slope. Slope is a steep surface unit, and the ratio of vertical height to horizontal width of slope is usually called slope. If the roof slope is selected reasonably, the waterproof effect of the roof will not be affected. The gradient is mainly determined according to the performance and structure of roofing waterproof layer materials. Generally, the room is 30 degrees, and the roof of the factory building is mostly 15 degrees. The slope of light steel roof is 5 degrees, and the maximum slope is 75 degrees.