1. Roll direction of the web. The laying direction of the coils should be determined based on the slope of the roof and whether there is vibration on the roof. When the roof slope is less than 3%, the coils should be laid parallel to the ridges; when the roof slope is 3% to 15%, the coils can be parallel or perpendicular to the roof ridges; when the roof slope is greater than 15% or when vibrated, the asphalt coils The material should be perpendicular to the roof ridge. Others may consider using parallel or vertical roof tiles according to the actual situation. From the cornice to the ridge layer, all kinds of coils should be connected one above the other, and the overlapping position of the multilayer coils should be staggered. The upper and lower coils must not be laid vertically.
2. The order of the webs. When constructing the waterproof layer, the nodes, additional layers, and roof drainage areas where the drainage is relatively concentrated (such as the connection between the roof and the water fallout, cornices, gutters, gutters, roof corners, plate joints, etc.) should be handled first. Construction works at the lowest elevation of the roof. When paving gutters and trenches, it is advisable to follow the direction of the gutters and eaves to reduce the overlap.
When laying roofs with multiple spans and roofs with high and low spans, it should be carried out in the order of height first, then low first, and first and last.
3. Web lap method and width. Lap-up method is adopted for the surfacing material. The overlapping joints of the upper and lower layers and the two adjacent coils should be staggered. The lap joints parallel to the roof ridges should overlap in the direction of the water flow: the lap joints perpendicular to the roof ridges should be smoothly connected with the prevailing wind direction. Laminated layers of membranes shall be cross-connected at the junction of the gutter and the roof. The lap joints shall be staggered; the seams shall be left on the sides of the roof or gutter and should not be left at the bottom of the trenches.
For arched roofs with a slope of more than 25% and slopes below the skylights, short-edge laps should be avoided as much as possible. When short-edge laps must be made, measures should be taken to prevent the roll-off of the coils at the lap joints.