Exposed polyurethane waterproof coatings arr_right_inav

Two-Component Polyaspartic Waterproof Coating

Description Specifications Scope of Application FAQ Download

Description

YHPAroof-8532 is a two-component, chemically cured, low-VOC, aliphatic polyaspartic polyurea waterproofing membrane designed for use as a pedestrian and vehicular traffic-bearing top coat. It can be applied alone or as atop layer over a high-performance aromatic polyurethane base coat, such as YHPUcoat-8200/8400.

Specifications

CHARACTERISTICS AND PACKAGING

Item	Data
Item	Clear	Tinted
Color	-	Grey, White, Blue, Red, Green, Yellow
Appearance	Viscous Liquid
Viscosity/mPa·s	A: 1200±300; B: 1400±100	A: 1200±300; B: 800±100
Density/kg/L	A: 1.03-1.10; B: 1.00-1.10	A: 1.03-1.10; B: 1.30-1.45
Mixing Ratio by Weight	A:B=2:1	A:B=1:1
Solid Content by Weight	94-97%
Pot life (23℃, 50%Rh)	50-60mins
Package Size	A: 9 kg/pail; B: 4.5 kg/pail	A: 6 kg/pail; B: 6 kg/pail

PROPERTIES

Description	Test Methods	Typical Values
Description	Test Methods	Clear	Tinted
VOC / g/L	ASTM D2369	75	94
Tensile Strength / MPa	ASTM D412	15.5±1.5	17.5±2.0
Elongation at Break / %	ASTM D412	500±100
Tear Strength / N/mm	ASTM D624	75±10
Pull-off Adhesion to Concrete / MPa	ASTM D7234	≥3.0
Shore A Hardness	ASTM D2240	90-93	92-97
Taber abrasion (750 g, 500 r, CS-10)	ASTM D4060	15mg	12mg
Taber abrasion (1000 g, 1000 r, CS-17)	ASTM D4060	30 mg	25 mg
Water Penetration Test (5 bar, 3 days)	DIN 1048-5	No Penetration
Low Temperature Flexure (-35 °C)	ASTM D522	No Cracks
Cure time for tack-free/h	ASTM D1640	1.5

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

APPLICATION INSTRUCTIONS

Materials Consumption

Material consumption depends on the porosity and texture of the substrate. Typically, it is approximately 1.0–1.1 kg/m² for a clear finish and 1.2–1.3 kg/m² for a tinted coat, per 1 mm dry film thickness.

Application Instructions

Substrate preparation: The substrate should be clean, dry, sound, and free of all contamination, such as dirt, oil, and grease. Concrete surface defects, such as blowholes and voids, must be repaired. The concrete should be cleaned and prepared to achieve a laitance-free, open-textured surface by blast cleaning or other mechanical means, if necessary. Filling of joints and surface leveling must be completed before coating. It is recommended to use an epoxy primer to seal the cementitious substrate, prevent coating pinholes, and enhance adhesion.

Mixing: Premix YHPUroof-8532 Part A and Part B separately before combining. Add Part B to Part A in the stipulated mixing ratio, and mix using a mechanical mixer at medium speed until a homogeneous mixture with uniform color is achieved. Take care to avoid whipping air into the material to prevent pinhole blisters or a shortened pot life.

Detailing: First, apply the coating to detail areas such as construction joints, water outlets, and concave and convex corners. For wide cracks, use sealant to skin over the surface, and install fabric reinforcement between two wet coats to ensure thorough penetration and full embedment. The total thickness of the composite coating layer should be at least 1 mm.

Coating application: Apply at the recommended coverage rate using a notched squeegee or roller. Spraying with a single-component sprayer after mixing is possible, but be mindful of the pot life. Extend the coat over the entire area, including previously detailed joints and cracks. The recoat time is typically 6–18 hours, though low temperatures may extend the waiting time. If slip resistance is required, apply a 0.2–0.4 mm thick wet film to the installed and cured coat, and broadcast dried aggregate onto the still-wet coat. Back-roll the surface to encapsulate the aggregate in YHPUroof-8532 resin. Alternatively, add 10 wt% of 160–200 mesh quartz sand to YHPUroof-8532 and mix thoroughly. Then, apply a 0.2–0.3 mm thick coat on a tack-free YHPUroof-8532 surface to serve as the anti-slip top layer.

Post-treatments: Seal the coating edges with UV-resistant sealant if necessary.

ADVANTAGES

· Outstanding resistance to abrasion and wear.

· Low viscosity. Easy application by spraying, roller, brush and squeegee.

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

· Resistant to water, deicing salts, diluted acid and alkaline.

· Good adhesion to most substrates.

· Super UV-resistance and color retention.

· Longer pot life compared with other plural-component high performance waterproof coatings.

Scope of Application

YHPAroof-8532 should only be used by experienced professionals. It is highly recommended as a pedestrian and vehicular traffic-bearing top coat in waterproofing projects, including multi-story parking garages, stadiums, and arenas. It can also be used in scenarios with long-term water immersion and/or water scour, such as outdoor swimming pools and water parks.

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.