Waterproofing Methods for the Roof of Prefabricated Panel Houses

The waterproofing methods for the roof of prefabricated panel houses mainly include color-steel roofs, waterproof membranes, plastic film covering, the 'three-scraping and two-sticking' method, and pouring concrete on the prefabricated panels followed by waterproofing.

1. Color-steel roofs: Made of metal panels with anti-rust coatings, they come in two installation styles: pointed and flat. Both offer the same rainproofing effect, but pointed roofs cost about 20% more than flat ones. They have a lifespan of 20 years and cost between 60 and 80 yuan per square meter.
2. Waterproof membranes: These are commonly used waterproofing materials, with the waterproofing effect depending on the quality of the membrane and the skill of the installers. The cost of the membrane alone is around a dozen yuan per square meter, but with installation fees, the total cost is not low. The lifespan is generally about 15 years. The installation steps are as follows:
   • Base treatment: Clean the prefabricated panel roof to ensure the surface is free of dust, sand, and debris, and repair any cracks or defects.
   • Applying waterproof coating: Follow the manufacturer's instructions and use appropriate tools to apply the coating evenly without omissions, achieving the specified number of coats.
   • Laying waterproof membranes: Lay the membranes according to the actual situation of the roof, paying attention to the treatment of seams between membranes to ensure they are seamless and gap-free.
   • Protective layer construction: After completing the waterproof layer, construct a protective layer on the surface, such as a mortar protective layer or a fine aggregate concrete protective layer, to enhance the durability of the waterproof layer.
3. Plastic film covering the entire roof: Cover the roof with plastic film, then secure it with objects or cover it with a layer of soil (or other covering materials). This method has a relatively short lifespan, generally around 2-3 years, but it is cheap, costing about 2 yuan per square meter.
4. The 'three-scraping and two-sticking' method: For large-area waterproofing, asphalt is used more often, while for small areas, waterproofing materials such as JS and leak-stopping agents are used. Using asphalt and felt, the 'three-scraping and two-sticking' method is applied, which provides good waterproofing results.
5. Pouring concrete on the prefabricated panels followed by waterproofing: Since there are gaps between the prefabricated panels, a 5-8 cm thick layer of concrete needs to be poured on them, with steel wire mesh placed inside to prevent cracks from forming over time, followed by waterproofing.

In addition, for waterproofing construction, high-quality materials should be selected, and operations should follow standards. Pay attention to details, especially at the joints of the floor slabs, air vents, and parapet walls. Strictly inspect the construction after completion. Regular maintenance of the waterproof layer is also necessary, including periodic checks to ensure it is intact and timely repairs if damage is found. Avoid drilling holes randomly on the roof or performing other operations that may damage the waterproof layer.