Waterproofing Methods for Prefabricated Panel Houses

Waterproofing for prefabricated panel houses requires a combination of structural reinforcement and multi-layer waterproofing treatments, with key points including gap treatment, material selection, comprehensive waterproofing, and addressing special circumstances.

1. Gap Treatment and Structural Reinforcement
Natural gaps exist at the joints of prefabricated panels, serving as primary channels for water leakage. A concrete layer 5 to 8 centimeters thick should be poured over the surface of the prefabricated panels, with steel wire mesh embedded inside. The concrete layer fills the gaps and forms an integrated waterproof base, while the steel wire mesh reduces cracks caused by concrete shrinkage or settlement through its tensile resistance, preventing the waterproof layer from failing due to base cracking. This step is fundamental to waterproofing and requires ensuring the concrete is dense and the steel wire mesh is firmly fixed.

2. Application of Multi-Layer Waterproofing Materials
Waterproofing construction should follow the principle of “three scrapes and two pastes”:

• Large areas: Asphalt should be prioritized as the main material for the waterproof layer. Asphalt should be applied in three coats (the “three scrapes”), with each coat applied perpendicular to the previous one to form a dense waterproof membrane; two layers of felt (the “two pastes”) should be sandwiched in between. The felt acts as a reinforcing layer, enhancing the tear resistance of the asphalt layer and extending its waterproof lifespan.
• Small areas or detailed parts: JS composite waterproof coating or leak-stopping agent should be used. JS coating is flexible and can adapt to minor deformations in the base; the leak-stopping agent is used for quickly sealing cracks or holes, forming a rigid waterproof barrier.

3. Comprehensive Waterproofing Treatment
Prefabricated panel roofs are prone to “water channeling,” where water penetrates horizontally through pores or gaps in the panels, causing the location of water leakage to differ from the actual water source. Merely treating the bottom or local areas of the roof cannot solve the problem; comprehensive waterproofing treatment of the entire roof is necessary, including easily leaky parts such as the ridge, eaves, and drainage outlets, ensuring the waterproof layer is continuous without breaks.

4. Addressing Special Circumstances
If it is impossible to cut grooves in the roof panels to block water penetration paths (due to structural constraints or construction difficulties), alternative solutions should be explored:

• Surface application of permeable crystalline waterproofing material: Generates insoluble crystals through chemical reactions, filling pores inside the concrete and forming an internal waterproof layer.
• Adding drainage slopes: Optimize the roof drainage design to reduce water accumulation time and lower the risk of leakage.
• Combining with flexible waterproof membranes: Lay polymer waterproof membranes on the concrete base to form dual protection, adapting to minor deformations in the base.

Waterproofing for prefabricated panel houses should be based on structural reinforcement, combining multi-layer materials and comprehensive construction to address gap leakage and water channeling issues, while flexibly adjusting solutions for special circumstances to achieve long-term waterproofing effects.