Exposed polyurethane waterproof coatings arr_right_inav

One-Component Polyurethane Waterproof Coating

Description Specifications Scope of Application FAQ Download

Description

YHPUroof-8531 is a single-component, cold-applied, moisture-cured aliphatic polyurethane waterproofing membrane. It cures to form a seamless and durable waterproofing layer suitable for outdoor applications with heavy pedestrian traffic. It can be applied either alone or as a top layer over a robust aromatic polyurethane base coat, such as YHPUcoat-8200 or YHPUcoat-8400. YHPUroof-8531 is a self-leveling coating. A highly thixotropic version for vertical applications is available upon request.

Specifications

CHARACTERISTICS AND PACKAGING

Item	Data
Appearance	Viscous Liquid
Viscosity/cp	7000±2000
Color	Grey
Density/kg/L	1.05-1.15 kg/L
Solid Content by Weight	85-87 %
Pot life/h	2
Packing Size	20 kg per metal pail

PROPERTIES

Description	Test Methods	Typical Values
VOC / g/L	ASTM D2369	≈180
Tensile Strength / MPa	ASTM D412	≥15
Elongation at Break / %	ASTM D412	≥450
Tear Strength / N/mm	ASTM D624	≥50
Pull-off Adhesion to Concrete / MPa	ASTM D7234	≥2.5
Shore A Hardness	ASTM D2240	≈70
Taber abrasion (750 g, 500 r, CS-10) / mg	ASTM D4060	≈20
Water Penetration Test (5 bar, 3 days)	DIN 1048-5	No Penetration
Low Temperature Flexure (-35 °C)	ASTM D522	No Cracks
Set-to-Touch Time / h	ASTM D1640	≈3

Note: The above data were tested under standard conditions (temperature 23 °C ± 2 °C, relative humidity 50% ± 10%).

APPLICATION INSTRUCTIONS

Items	Description
Consumption*	1.25-1.40 kg / m2 for 1mm dry film
Coverage	9-11 m2/set (20kg) at 1.5mm dry film thickness
Recommended thickness	1.2-1.5 mm by 2 coats 1.0-1.2 kg / m2 / coat at 0.7-0.8 mm dry film thickness
Ambient air temperature	5 °C min / +40 °C max
Relative air humidity	<85%
Substrate temperature	5 °C min. / +40 °C max. ≥ 3 °C above dew point, beware of condensation

*Material consumption depends on the porosity and texture of the substrate.

ADVANTAGES

· Cold-applied and moisture-cured; no mixing, heating, or flame is required.

· Excellent crack-bridging properties and flexibility, even at low temperatures.

· Resistant to water, deicing salts, diluted acids, and alkalis.

· Good adhesion to most substrates. Adhesion is enhanced when bonding with an epoxy primer.

· UV-resistant and non-yellowing.

Scope of Application

YHPUroof-8531 is recommended for footbridges, balconies, terraces, roof walkways, stadiums, and other outdoor waterproofing projects with heavy pedestrian and/or casual vehicular traffic.

FAQ

Q1: Can waterborne polyurethane be stored at temperatures below 0 degrees Celsius?

No. Waterborne coatings use water as a solvent. When stored below 0 degrees Celsius, the water in the formulation freezes, causing physical damage to the coating. Freezing may form ice crystals, which disrupt the emulsion structure of the polyurethane, leading to irreversible separation, thickening, or gelation.
Q2: What factors affect the curing speed of polyurethane?

Air temperature, humidity, mixing ratio, coating thickness, air circulation, substrate properties, and atmospheric pressure—all of these factors can affect the curing speed.
Q3: What are the factors that may affect the film-forming quality of moisture-cured one-component polyurethane？

There are several factor affect the drying speed for on-component Substrate profile; Air humidity; Substrate humidity; Coating thickness, etc.
Q4: What are the differences between aliphatic polyurethane and aromatic polyurethane?

The core difference between aliphatic polyurethane and aromatic polyurethane originates from the presence or absence of aromatic groups (such as benzene rings) in their molecular structures. This structural disparity directly leads to significant differences in their properties and application scenarios. The typical raw materials for aliphatic PU are hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), etc. The typical raw materials fo aromatic PU are Toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), etc. Due to the absence of benzene rings, the molecular structure exhibits stronger stability against ultraviolet (UV) light, with excellent weather resistance. It is less prone to photo-oxidative degradation, maintaining color stability and resisting yellowing after long-term exposure to outdoor or light environments.
Q5: What are the uses of exposed polyurethane?

Exposed polyurethane is widely used in scenarios requiring long-term outdoor exposure or harsh environments due to its excellent weather resistance, mechanical properties, and environmental adaptability. Below are its typical application areas and technical analysis: Roof waterproofing and refurbishment, outdoor water tank, footbridges, balconies, terraces, roof walkways, parking garages, and other outdoor waterproof projects with pedestrian and/or vehicular traffic.