Prefabricated House Waterproofing

Waterproofing for prefabricated houses requires targeted measures based on structural types, with the core principle of prioritizing the handling of joint gaps and dynamic deformation issues, selecting appropriate materials, and ensuring standardized construction.

1. Waterproofing for Prefabricated Roof Panels

1. Structural Characteristics and Leakage Challenges

   • The jointed structure makes panel seams the primary channels for water infiltration. These seams are prone to cracking and displacement due to temperature variations and settlement. Substrate defects (such as sanding and cracking) can cause hidden water migration, while dynamic deformation can render ordinary waterproofing materials ineffective. The gutter area requires enhanced weather-resistant waterproofing techniques.
   • Key Points: Panel seams are the core of leakage and require focused reinforcement; dynamic deformation necessitates materials with flexibility.

2. Standardized Construction Plan

   • Substrate Preparation: Remove obstacles, repair cracks and loose or sandy areas, and ensure a flat and solid substrate.
   • Panel Seam Reinforcement: Use rigid filling materials (such as cement-based fillers) to reinforce joint seams and prevent cracking.
   • Comprehensive Protection: Cover the entire roof with national standard thickened waterproof membranes (such as SBS modified bitumen membranes). For the gutter area, adopt specialized exposed waterproofing techniques (such as a combination of weather-resistant sealant and waterproof coating).
   • Warranty Service: Provide a 5-year written warranty upon project completion to ensure long-term effectiveness.

2. Waterproofing for Prefabricated Exterior Wall Panels

1. Design Concept Adjustment

   • The traditional “water blocking” concept is not applicable. Instead, follow the principle of “water diversion over blocking, drainage over waterproofing.” Guide water flow out through tongue-and-groove joints and pressure-relief cavities, combined with rubber water stops and weather-resistant waterproof adhesives to complete the system.
   • Key Points: Focus on drainage to reduce direct water pressure impact on the structure.

2. Joint Waterproofing Forms

   • Cast-in-Place Exterior Hanging (PCF Panels): Install drainage cavities on the exterior and apply sealant, relying on the self-waterproofing of cast-in-place concrete on the interior to form dual protection.
   • Externally Hung Prefabricated Wall Panels: Adopt a closed linear waterproofing form, requiring regular inspection for cavity blockages to prevent water accumulation and leakage.

3. Waterproofing for Rural Prefabricated Floor Roofs

1. Common Causes of Leakage

   • Prefabricated floors have numerous joint seams and weak structural integrity, making them prone to leakage due to deformation. Targeted treatment of seams and dynamic loads is necessary.

2. Solutions

   • Color Steel Roof: Install whole metal panels with press-fit connections. The anti-rust coating extends the service life (approximately 20 years), with a cost of 60-80 yuan per square meter, suitable for long-term use.
   • Waterproof Membrane: Relies on material quality and construction techniques, with a service life of about 15 years. Choose a professional team for construction to avoid leakage due to defects.
   • Plastic Film Covering: A short-term, low-cost solution (2-3 years), suitable for emergency repairs but with poor durability, requiring regular replacement.

Summary: Waterproofing for prefabricated houses requires selecting appropriate solutions based on structural types (roof, exterior wall, floor), focusing on handling joint seams and dynamic deformation issues, prioritizing materials with strong weather resistance and flexibility, and ensuring standardized construction to achieve long-term waterproofing effects.