Views: 0 Author: Site Editor Publish Time: 2026-01-24 Origin: Site
When the polyurethane rigid foam waterproof and thermal insulation integrated board is constructed on the roof, on-site spraying technology is mainly used to form a seamless waterproof and thermal insulation layer, and combined with the construction of a protective layer to ensure the durability of the system. The following are the specific methods and key points:
1. Construction process
Grassroots processing
Clean the roof base layer to ensure that there is no looseness, oil, dust and other impurities, and the surface flatness deviation does not exceed 3mm/m².
Repair cracks and holes in the base layer. When the moisture content is too high, you need to apply an interface agent or spray water to moisten it (but avoid water accumulation).
Nodal parts such as yin and yang corners, parapets, and drains must be made into arc shapes (radius 80-100mm) to facilitate uniform spraying.
Node details
Pipes passing through the roof: Set up waterproof casing, mortar 'R' type closing, spraying height is not less than 300mm, and the closing head is fixed with a clamp.
Downspout: The distance between the bottom of the horizontal downspout and the base is 10mm, and the inner side is flush with the wall; the upper part of the vertical downspout is 5mm higher than the base.
Flooding parts: Cover with cement mortar and install steel wire mesh. The steel wire mesh is fixed to the base layer through insulation nails.
Polyurethane rigid foam spray
Equipment and materials: A two-component high-pressure airless spray machine is used to mix the raw materials in a 1:1 ratio to ensure uniform mixing and sufficient thermal reaction.
Spraying parameters: The distance between the spray gun and the base surface is 500-700mm. Spray in separate passes. The thickness of each pass is ≤15mm. The total thickness is based on the design requirements (usually 40-60mm).
Foaming control: No one is allowed to visit within 20 minutes after spraying, and trimming should be done after 24 hours (such as using a portable planer or hacksaw to remove excess parts).
Protective layer construction
Non-accessible roof: Apply interface agent and then embed anti-cracking putty (fiberglass mesh is pressed into the interior).
On the roof: Pour a 40-60mm thick protective layer of reinforced fine stone concrete, and use non-woven fabric or plastic film as an isolation layer before laying.
2. Core advantages and characteristics
Integrated waterproofing and thermal insulation
The closed cell rate of polyurethane rigid foam is as high as over 95%, the water absorption rate is ≤1%, and the thermal conductivity is as low as 0.022W/(m·k). It also achieves waterproof and thermal insulation functions.
On-site spraying forms a seamless whole, eliminating the risk of leakage at the joints of traditional materials.
Lightweight and high strength
40mm thick polyurethane rigid foam weighs only about 2.4kg per square meter, which significantly reduces the roof load and is suitable for high-rise buildings and long-span structures.
The compressive strength is ≥300KPa and can be adjusted to more than 600KPa according to needs to meet different load-bearing requirements.
Efficient construction
Mechanized spraying, the daily construction area of a single machine can reach 500-1000 square meters, saving 80% of the construction time compared with traditional materials.
It can be cured in 30 minutes after spraying, shortening the construction period.
Strong durability
It is resistant to aging, has stable chemical properties, has a service life of more than 50 years, and has low maintenance costs.
The bonding strength with concrete, metal, wood and other base surfaces is ≥100KPa, and it has excellent wind resistance.
3. Key points of quality control
Thickness control: Ensure that the thickness of the insulation layer meets the design requirements through sampling testing (for example, when the roof heat transfer coefficient is ≤0.27W/m²·K, the thickness of the spraying system is 120mm + 50mm protective layer).
Obturator rate detection: After cutting off the surface of the sample, the water absorption rate is tested. The actual measured value is ≤1%, which proves that the obturator structure is excellent.
Bonding strength test: Verify the bonding performance with the base layer through a pull-out test to ensure there is no hollowing or falling off.
4. Application scenarios
Industrial and civil buildings: flat roofs, pitched roofs, special-shaped roofs (such as villas, planting roofs).
Special projects: data centers, power plant steel structure energy-saving roofs, electronic factories and other scenarios that require high waterproofing and insulation.
Energy-saving renovation: Energy-saving renovation of existing building roofs without the need to dismantle the original roof layer and spray construction directly.
