Roofs are constantly exposed to rain, sunlight, and high temperatures; consequently, the selection of a waterproofing system is the most critical aspect of roofing projects. For large-scale roofs and exposed building structures in particular, waterproofing coatings require not only effective waterproofing capabilities but also excellent adhesion and flexibility.
Exposed polyurethane (PU) waterproofing coatings are a common solution for such projects. Applied in liquid form, they create a seamless, continuous waterproof membrane on the roof surface and are suitable for concrete roofs, flat roofs, terraces, balconies, and various other roofing applications.
What is Polyurethane Waterproof Coating for Roofing?
Exposed solvent-based polyurethane roof waterproofing is a single-component, high-solids polyurethane waterproofing membrane suitable for concrete surfaces, including walls and roofs.
Why Liquid-Applied PU Waterproofing Coating Is Over Sheet Membranes
Sheet-based water proofing paint for roof require the careful treatment of overlaps and seams, as well as the sealing of edges, corners, and penetrations. The quality of workmanship at these specific points directly impacts the continuity of the entire waterproofing layer. Liquid polyurethane (PU) waterproofing coatings differ in this regard; they form a continuous waterproof membrane directly on the roof surface, providing seamless coverage across both large areas and intricate details. Furthermore, PU coatings possess inherent flexibility, allowing them to accommodate movement caused by temperature fluctuations, making them an ideal choice for a wide range of exposed roofing projects.
Key Performance Properties of Polyurethane Waterproofing Coatings
1) Easy to apply; no special substrate requirements.
2) High tensile strength and elongation; excellent performance across high and low temperatures.
3) Strong adhesion; no additional chemical additives required.
4) Color can be customized to meet specific customer requirements.
2) High tensile strength and elongation; excellent performance across high and low temperatures.
3) Strong adhesion; no additional chemical additives required.
4) Color can be customized to meet specific customer requirements.
Common Applications for PU Waterproofing Coatings
Exposed-grade PU waterproofing coatings are suitable for various outdoor roofing and wall surfaces, such as:
Concrete roofs — flat roofs, roof slabs, and other exposed concrete surfaces.
Masonry roofs — brick and masonry roofing.
Uncoated metal roofs — metal roofing without existing coatings.
Concrete exterior walls — walls exposed to rain and weather conditions over the long term.
Masonry roofs — brick and masonry roofing.
Uncoated metal roofs — metal roofing without existing coatings.
Concrete exterior walls — walls exposed to rain and weather conditions over the long term.
Tengyu PU Waterproof Coating Solutions
Are you looking for polyurethane waterproof coatings suitable for exposed roofs and exterior building surfaces? Tengyu TW330 Exposed PU Waterproof Coating is for applications where the waterproofing layer is directly exposed to sunlight and outdoor environments; it is suitable for concrete roofs, brick and masonry surfaces, uncoated metal roofs, and exterior walls.
Please contact Tengyu for project specifications, samples, packaging options, or OEM/private label services; we can provide product recommendations and supply support tailored to your project needs.
Q1. What is the difference between aliphatic PU and aromatic PU waterproof coatings?
Aliphatic PU offers superior UV resistance and color retention, making it suitable for applications involving long-term exposure, such as exposed roofs and exterior walls. Aromatic PU is more sensitive to UV radiation and is suitable for applications not subject to prolonged exposure.
Q2. Can PU waterproof coatings be used on old roofs?
Yes, but substrate preparation is on the condition of the existing roof. Before application, remove any loose or damaged old coatings, repair cracks and damaged areas, and ensure the surface is clean and structurally sound.
Q3. Is a primer for PU waterproof coatings?
In most cases, yes. A compatible primer helps improve adhesion between the waterproof coating and the substrate. The necessity of a primer and the choice of primer should be determined based on product specifications and substrate conditions.
Q4. How many coats of PU waterproof coating are required?
1. Surface Preparation: The substrate surface must be dry, sound, and free of dust, oil, or loose debris. Fill any cracks and joints with sealant before applying the coating.
2. Application: Generally, a thickness of 1.5 mm is achieved after applying 3–4 layers. Consumption is approximately 1.8 kg per square meter. After applying the first layer, allow the surface to dry (about 3–4 hours) before applying the second layer.
3. Curing: Complete curing takes 24–72 hours. Avoid contact with water or rain during the curing period.
2. Application: Generally, a thickness of 1.5 mm is achieved after applying 3–4 layers. Consumption is approximately 1.8 kg per square meter. After applying the first layer, allow the surface to dry (about 3–4 hours) before applying the second layer.
3. Curing: Complete curing takes 24–72 hours. Avoid contact with water or rain during the curing period.