Waterproof backing plate

1. Definition and core functions of waterproof backing plate

Definition: Waterproof backing plate is a kind of building plate used in humid environments (such as toilets, kitchens, bathrooms). It is used as the base layer of tiles, stone and other finishing materials. It has excellent waterproof and moisture-proof properties to avoid moisture deformation and mildew of the base layer. Ensure long-term stability of the finish.

2. Main types and material characteristics

1. Cement based waterproof backing plate

1) Material composition: cement + quartz sand + glass fiber mesh cloth (or polyester fiber), high-pressure formed, density ≥ 1800 kg/m3.

2) Performance characteristics: Flexural strength ≥ 10 MPa, water absorption ≤ 0.2%, direct contact with water source; fire protection rating A1, strong weather resistance.

3) Applicable scenarios: bathroom walls, kitchen countertops

2. PVC waterproof backing

1) Material composition: polyvinyl chloride (PVC)+ calcium carbonate filler, extruded, density 1300 - 1500 kg/m3, surface covered with weatherproof film.

2) Performance characteristics: light weight (about 1/3 of cement board), good flexibility, and flexible construction; acid and alkali resistance, and mold resistance.

3) Applicable scenarios: curved wall of shower room, bathroom partition

3. Magnesium waterproof backing plate

1) Material composition: magnesium oxide + magnesium chloride + glass fiber mesh, cured and cured, density 1000 - 1200 kg/m3, porous surface structure.

2) Performance characteristics: Low thermal conductivity and good thermal insulation; after absorbing moisture, it can release moisture and adjust air humidity.

3) Applicable scenarios: humid basements, surrounding swimming pools

4. Glass fiber reinforced cement board (GRC)

1) Material composition: cement + alkali-resistant glass fiber + additives, density 1600 - 1800 kg/m3, thickness 6 - 12 mm.

2) Performance characteristics: High impact strength (can withstand a load of 50 kg/m2), strong aging resistance, and adhesive force with ceramic tiles ≥ 0.5MPa.

3) Applicable scenarios: commercial bathrooms, public toilets

3. Key performance indicators and technical advantages

1. Waterproof and moisture-proof performance

1) Water absorption test: After soaking for 24 hours, the water absorption of cement-based board is ≤ 0.2%, and that of PVC board is ≤ 0.1%, which is much lower than that of ordinary gypsum board (water absorption ≥ 10%).

2) Impermeability: Water sprayed on the back of the plate (pressure 0.1MPa), and there is no penetration trace on the front. It is suitable for long-term humid environments.

2. structural stability

1) Thermal expansion and contraction rate: Linear expansion coefficient of PVC board ≤ 0.07mm/m?℃, cement substrate ≤ 0.02mm/m?℃ to avoid cracking of the finish due to temperature changes.

2) Anti-deformation ability: When the span is 600 mm, the deflection of the cement base plate is ≤ 1.5 mm, which meets the flatness requirements of ceramic tile laying (error ≤ 2 mm/2 m).

3. Environmental protection and safety

1) Formaldehyde emission: PVC board and cement base board both reach E0 (≤ 0.05mg/m3). Magnesium board should pay attention to the magnesium chloride content (chloride ion ≤ 0.1%) to avoid corrosion of metal embedded parts.

2) Fire protection rating: cement-based and GRC boards are A1 non-combustible materials, and PVC boards are refractory B1, complying with building fire protection codes.

4. Application Scenarios and Cases

1. Residential areas: The wall of the wet and dry separation area in the bathroom (with tiles or marble); the back wall of the kitchen sink (to prevent dampness and mold in the cabinet).

2. Commercial field: hotel bathroom partitions (PVC panels are light and easy to install); hospital operating room walls (cement base panels are antibacterial and easy to clean).

3. Special scenes: swimming pool locker room (magnesium plate regulates humidity); seafood market stall countertops (GRC plate resists acid and alkali corrosion)

V. Industry development trends

With the popularization of prefabricated decoration, waterproof backing plates are developing towards "lightweight + functional integration", such as: composite boards with integrated insulation layers (thermal conductivity ≤ 0.04W/(m. K)), suitable for energy-saving buildings; The adhesive-free mounting board with its own adhesive layer increases construction efficiency by 30%. In the future, environmentally friendly magnesia boards and recyclable PVC boards will become the materials of choice for green buildings. If specific brand recommendation or construction plan design is needed, further analysis of project environmental parameters can be provided.