United Coatings Unisil HS Roof Coating


United Coatings Unisil HS Roof Coating is a high-solids, moisture-cure silicone coating that provides superior weatherproofing, ultraviolet resistance, biological resistance and fire retardancy over polyurethane foam insulation and other appropriate substrates. The pure silicone polymers are naturally fire retardant to provide long-term fire resistance, while the tight surface finish affectively resists the attachment of algae, mildew and mold organisms.

Sizes Available:

1 gallon (3.8 liter) bucket
5 gallon (19 liter) pail
50 gallon (189 liter) drum


United Coatings Unisil HS Roof Coating is designed to be applied over SPF insulated concrete, metal, plywood, ambient and hot tanks. It is built for protecting a wide range of substrates from the effects of moisture intrusion and weathering, is particularly effective as a protective coating over polyurethane foam on new or existing roofs.

Unisil HS Roof Coating is a single-component elastomer that exhibits a rapid cure when exposed to ambient conditions.

A minimum of 1 coat could be applied. If there are subsequent coats of United Coatings Unisil HS Roof Coating then apply other coats as soon as the previous coat is completely dry and within 24 hours to avoid inter-coat delamination. All surfaces must be uniformly coated and free from voids, pinholes, or blisters.

Physical Properties

Solids by Weight 96% (±2) [ASTM D1644]
Solids by Volume 96% (±2) [ASTM D2697]
Flash Point (COC) 290°F (143°C) [ASTM D92]
Dry Time to Walk On 2–4 hours @ 75°F (24°C), 50% R.H.
Tensile Strength 330 psi (2.3 MPa) (±25)
[ASTM D2370]
Elongation 200% (±10) [ASTM D2370]
Hardness 45–55 Shore A [ASTM C661]
Permeance 5.9 US Perms @ 30mils (762 microns)
[ASTM E96, Procedure B]
Resistance to
After 5,000 hours of continuous
exposure, Unisil HS Roof Coating had
no deleterious effects, no surface
checking or cracking, no delamination
and no color fade. [ASTM D6694]
Flexibility After
After 5,000 hours exposure in the
QUV Accelerated Weathering Cabinet,
Unisil HS Roof Coating retains its
ability to withstand multiple 1” (2.5
cm) mandrel bends at 2°F (-17°C)
without cracking. [ASTM D4338]
Solar Reflective
Index (SRI)
110 - Unisil HS White [ASTM E1980]
Emissivity 0.89 - Unisil HS White [ASTM C1371]
VOC < 50 g />L [ASTM D3960]
Specific Gravity 1.29 @ 77°F (25°C) [ASTM D1875]
Water Absorption 0.1% weight gain after 2 weeks
immersion at 75°F (24°C)
[ASTM C1371 / ASTM D471]
Temperature Limits
for Normal Service
-80°F to 350°F (-62°C to 177°C)
Max 185°F (85°C) continuous
High Temperature
Tested in thermostatically controlled
heat chamber. Will not age harden or
slump at temperatures up to 350°F
(177°C). [ASTM D794]
Low Temperature
Capable of withstanding 180° bends
over a 1” (2.5 cm) mandrel @ 2°F
(-17°C). [ASTM C734]
Resistance to
Test panels exposed to freeze-thaw
cycles under complete immersion in
deionized water. Cycles consisted of 16
hours at 0°F (-18°C) and 8 hours at 70°F
(21°C). After 4 complete cycles, the
physical integrity of the coating remained
unaffected. There was no loss of
adhesion and no blistering or softening.
Standard Colors White, Lt Tan, Lt Gray, Tan, Gray
Custom: Terra Cotta


All documents are U.S. English unless otherwise noted

Commercial Roofing EagleView Commercial Property Owners Portal Architects And Specifiers


Product Princing and Where to Buy
© Copyright 2019 GAF | Privacy Policy and Legal | GAF Canada | GAF U.S.