Prefabricated Panel Factory Building Roof Design Drawing

Currently, there is no directly available complete design drawing for the roof of a prefabricated panel factory building, but local design references can be made based on relevant node drawing information, and a complete design needs to be deepened in combination with specific project requirements.

The roof design of a prefabricated panel factory building requires comprehensive consideration of multiple factors. The following introduces the design from several key nodes:

• Prefabricated Roof Structure Layers (Grade I Protection): This is the basic part of roof design. Grade I protection implies high requirements for waterproofing, thermal insulation, and other performance aspects. In terms of structural layers, it usually includes a structural layer, typically using prefabricated panels as the load-bearing main body; a waterproof layer, selecting reliable waterproof materials such as membranes or coatings to prevent rainwater leakage; a thermal insulation layer, choosing appropriate thermal insulation materials according to local climate conditions and building energy efficiency requirements, such as polystyrene boards, to improve the roof's thermal insulation performance; and a leveling layer, providing a flat base for the waterproof layer to ensure the waterproofing effect.
• Flashing at Gable and Longitudinal Walls: The junctions between the gable walls, longitudinal walls, and the roof are prone to leakage, making flashing design crucial. The flashing should be made to a certain height and slope, generally with a height of not less than 250mm and a slope of not less than 5%, allowing rainwater to drain smoothly. At the same time, an additional waterproof layer should be installed at the flashing area to enhance waterproofing capability and prevent rainwater from infiltrating the interior through the junctions.
• Expansion Joints (Equal-height/Unequal-height): When the length or width of the factory building is relatively large, expansion joints need to be installed to prevent roof cracking caused by factors such as temperature changes and foundation settlement. Equal-height expansion joints are suitable for situations where the roof heights on both sides are the same, while unequal-height expansion joints are used when the roof heights on both sides are different. Elastic sealing materials, such as bituminous hemp fibers and foam plastics, should be filled inside the expansion joints, and the upper part should be covered with waterproof membranes to ensure the waterproofing and sealing performance at the expansion joints.
• Panel Joint Treatment (Ridge Joints/Butt Joints): The treatment of panel joints between prefabricated panels directly affects the overall integrity and waterproofing performance of the roof. Ridge joints refer to the panel joints in the direction of the roof slope, while butt joints refer to the panel joints perpendicular to the roof slope. For ridge joints, filling materials such as cement mortar and oil paste are generally used for filling, and waterproofing treatment is carried out on the surface; for butt joints, cover plates can be used for covering, and the cover plates should be firmly fixed to the prefabricated panels to prevent rainwater from infiltrating through the panel joints.
• Internal Gutters and Eaves: Internal gutters are used to collect and discharge roof rainwater. When designing, their drainage capacity and waterproofing performance should be considered. The slope of the gutters should generally be not less than 1% to ensure rapid drainage of rainwater. Eaves serve to protect the walls and doors and windows, while also adding to the building's aesthetics. The overhang length and height of the eaves should be determined according to actual conditions, and proper waterproofing treatment should be carried out.