TPU (Thermoplastic Polyurethane) is used in building waterproofing in various forms, including waterproof breathable membranes, waterproofing sheets, hot melt adhesive films, and coatings, to meet the waterproofing, moisture-proofing, and sealing needs of different scenarios.
√ Main Application Forms and Examples
- Waterproofing Sheets / Membranes: Used as high-performance waterproof layers for large-area projects such as roofs, basements, tunnels, bridges, and reservoirs.
- Waterproof Breathable Membranes: Allow water vapor to escape while effectively blocking external liquid water penetration – suitable for the outer side of insulation layers to enhance building airtightness, used for walls, roofs, and wooden structures.
- Waterproof Sealing Materials: Used for joints, fence edges, pipe roots and other details, or as water-swellable sealing materials for expansion and construction joints.
- Waterproof Coatings: Applied as a coating onto concrete, metal, and other substrates to form a seamless waterproof film – suitable for pools, industrial floors, etc.
- Laminated Safety Glass: High-strength, tough TPU film firmly bonds glass fragments to prevent shattering – used in high-end curtain walls and skylights.
√ Typical Technical Parameters and Performance
- Physical/Mechanical Properties:
Tensile strength of waterproof sheets is typically 30–45 MPa, elongation at break 500–700%, thickness 0.2–0.5 mm.
Composite TPU fabrics have puncture resistance ≥80 N/mm² and elongation at break ≥300%. - Durability and Stability:
Melting point approx. 90°C, heat deflection temperature 70–90°C.
After 500 hours of heat aging at 80°C, tensile strength loss <5%.
Stable performance at -40°C; some grades can be used down to -65°C. - Environmental & Safety:
TPU is non-toxic, odorless, and environmentally friendly.
100% solid powder form gives zero VOC emissions, meeting green construction requirements.
√ Construction and Usage Points
- Blending Applications: For example, mixing 69.2% TPU, 30% rubber powder, and 0.8% defoamer can produce cost-effective functional waterproof materials for high-speed railway waterproof sealing layers.
- Process Selection:
- TPU powder: scatter coating + hot pressing
- TPU hot melt film: high-frequency or ultrasonic welding
- TPU sheet: hot air welding or special adhesives for overlapping
- Thermal Stability is Critical: Water resistance is essential for building waterproofing. Some TPU formulations degrade significantly in long-term hot water; prolonged high humidity may induce hydrolysis leading to seal failure. Therefore, selecting a hydrolysis-resistant grade is very important.
- Surface Treatment is Essential: On porous or smooth substrates, using a compatible primer significantly improves adhesion between the TPU coating and the substrate, ensuring overall integrity of the waterproof layer.
- For building waterproofing applications, polyether-based TPU made by Yantai Linghua new material is usually the better choice because its ether bonds (-C-O-C-) offer stronger hydrolysis resistance and are more suitable for long-term wet environments.
Post time: Jun-10-2026