Waterproofing of Precast Slabs in Rural Houses

Waterproofing solutions for precast slabs in rural houses include color-steel roofs, waterproof membranes, and plastic film coverage, among others, and should be selected based on budget and service life requirements.

Waterproofing the roof of precast slabs presents certain challenges. A common issue is the tendency for water to seep through, even when multiple layers of waterproof membranes are laid, and the likelihood of leaks is relatively high in rural self-built houses with precast slab roofs. To address these problems, the following solutions are available:

• Color-steel roofs: Made of metal sheets with anti-rust coatings, they are generally installed as whole pieces and rarely leak. There are two installation methods: pitched roofs and flat-laid installations. Pitched roofs cost about 20% more than flat roofs, have a service life of 20 years, and cost between 60 and 80 yuan per square meter. Color-steel roofs not only offer excellent waterproofing but are also relatively easy to install and have a long service life, making them suitable for rural houses with high waterproofing requirements and a certain budget.
• Waterproof membranes: These are commonly used roof waterproofing materials, and their effectiveness depends on the quality of the membranes and the skill level of the installers. Some leaks are caused by installer errors, and waterproofing contractors often wait until after the rainy season to collect payment. The cost of waterproof membranes alone is around a dozen yuan per square meter, and with installation fees, it is not cheap. The service life of the membranes is generally about 15 years. Choosing high-quality waterproof membranes and hiring skilled installers can, to a certain extent, solve the waterproofing problems of precast slab roofs.
• Covering the entire roof with plastic film: Using sufficiently wide plastic film to cover the roof and then securing it or covering it with a layer of soil (or other covering material) can perfectly solve the problem of leaks, but the service life is relatively short, generally 2-3 years. The advantage is that it is inexpensive, typically costing around 2 yuan per square meter. This method is cost-effective and suitable for rural houses with limited budgets and low requirements for service life to temporarily solve the problem of leaks.

In addition, precast slab roofs have poor thermal insulation, resulting in high indoor temperatures in summer and low indoor temperatures in winter. Generally, a secondary roofing material needs to be laid on the floor slab to compensate for this drawback.