Roof waterproofing typically begins with a base layer made of either cast-in-place or precast concrete slabs, along with cement mortar screed. In some cases, in-situ foamed polyurethane is used as a standalone material, serving both as a waterproofing and insulating layer, or as part of a multi-layer system. 1. Rigid Foamed Polyurethane 1.1 Performance Characteristics Rigid foamed polyurethane stands out for its exceptional thermal insulation properties, with a thermal conductivity as low as 0.033 W/(m·K). Its internal structure features a high sealing ratio of over 92%, with a smooth, closed-cell surface that offers near-perfect water resistance. It has a compressive strength exceeding 150MPa at a density of 40kg/m³ and demonstrates good elasticity with an elongation rate of around 10%. This material adheres well to various surfaces such as metal, concrete, masonry, wood, and glass. 1.2 Application Methods This material can be applied using two main techniques: on-site spray foaming and precast composite panels. The spray method involves mixing two components during application, which react immediately to form the foam. This technique is ideal for large-scale projects. When field conditions are not suitable for spraying, precast boards can be installed, and gaps can be filled using a foaming gun for effective results. 1.3 Scope of Use Rigid foamed polyurethane is widely used in roofing systems. It serves as a waterproof and insulating layer or is combined with other materials like waterproof membranes or coatings. On sloped roofs, it is often applied directly to the base concrete before tile installation. However, due to its limited UV resistance, a protective layer is necessary. In flat roofs, it can be used alongside other waterproofing materials, positioned beneath the waterproof layer. To address insulation issues in flat roofs, structurally sloped designs using rigid foamed polyurethane are recommended. 2. Biaxially Stretched PVC Sheet Biaxial stretching enhances the physical and mechanical properties of PVC sheets by reorienting the molecular chains. This process ensures a uniform UV protection layer that integrates seamlessly with the PVC surface. As a result, the material becomes more durable, resistant to weathering, and suitable for long-term use in harsh environments. 2.1 Key Features The sheet exhibits excellent impact resistance, up to 1200 kJ/m², and can withstand heavy impacts, such as a 30mm stone or a 50kg sandbag dropped from 120cm. It remains functional at temperatures as low as -30°C and maintains high light transmission (up to 90%) over time. It is also highly resistant to corrosion, UV exposure, and fire, making it a reliable choice for building applications. 2.2 Dimensions The thickness ranges from 0.6mm to 2mm, with a width of approximately 1.1m. Lengths can be customized based on project needs, usually not exceeding 22 meters. 2.3 Applications These sheets are commonly used for waterproofing large public buildings, industrial facilities, greenhouses, and outdoor structures. They are also suitable for interior partitions, soundproof walls, safety enclosures, and architectural elements like guardrails and tunnels. 3. Co-Extruded Sandwich PVC Foam Board Co-extruded sandwich PVC foam boards are gaining popularity in China due to their lightweight, durability, and aesthetic appeal. These boards resemble small asbestos tiles or European-style tiles, offering flexibility in size and color options. 3.1 Performance Features They are lightweight, flexible, and easy to cut, nail, or glue. They resist weathering, UV damage, and moisture while providing good insulation and fire resistance. Their versatility allows them to be used in both interior and exterior applications. 3.2 Usage Scenarios These boards are ideal for sloped roofs in residential, commercial, and industrial buildings. They can also be used for wall cladding, partitions, and decorative elements. Thickness ranges from 2mm to 20mm, with widths between 880mm and 1040mm, and lengths customizable according to demand. Brass fasteners are used for their physical and aesthetic properties. Brass is utilized due to its high thermal conductivity and corrosion resistant properties, it is suitable for use in hot and cold environments, and resistant to water corrosion, making it a staple of industries such as heating and plumbing. Brass fasteners are largely non-magnetic (like any fastener, slight magnetic properties can develop during the manufacturing process) and resistant to tarnishing. Brass Nut,Adjustable Brass Nut,Brass Strat Nut,Brass Cap Nut Taizhou Hongchuang Hardware Co., Ltd. , https://www.taizhouhongchuang.com
Brass fasteners are suited for some marine environments, including brackish water and slow current sea water; brass in this environment develops a protective green coating. Brass fasteners are also commonly used with wood applications, as the golden coloring blends well with the tan wood. Brass is a softer metal and must be used with care, always drilling pilot holes and using driver bits that fit the head of the screw precisely to prevent stripping. Brass Bolts also require a pilot hole be driven before installtion.