Thermo-Flex 103

For use on positive slope roof surfaces. This elastomeric cool roof coating is designed to protect, preserve and take the load off of HVAC systems for residential and commercial roof applications. Designed as prime and top coat.

SKU: 103 Categories: ,
This product comes in a selection of colors. Should you wish to order a special color, please call customer service at 800-275-5628 during our business hours and we’ll be happy to assist you.

If you need to order quantities of 50 gallons or more, please call us at 800-275-5628 for the best price and to save on shipping.

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A water-based, insulating highly flexible, elastomeric coating formulated with premium 100% acrylic resins and titanium dioxide to provide maximum bond strength. This combination ensures superior flexibility and strength, forming a continuous rubber-like blanket of protection that will expand and contract with your roof. The insulating barrier reduces heat transfer of building materials by reflecting back 80% to 90% of the sun’s rays, resulting in improved comfort levels, lower heating and colloing load requirements and costs. Additional chemical agents are also incorporated to resist the effects of ultraviolet sunlight exposure, as well as mold and fungus growth in warm and humid climates. Thermo-Flex 103 is exceptional on roof surfaces subject to high expansion and contraction.


Thermo-Flex 103 is engineered and developed to perform well under sever commercial, residential, industrial, agricultural and institutional applications. Use on asphalt, fiberglass, or asbestos shingles, concrete or clay tile, rolled roofing, B.U.R. roofs, metal roofing (baked enamel, aluminum and corrugated) and single ply roofing (EPDM, TPO, PVC). If rusted metal is present, you must apply a spot primer to the rusted area — see Metal-Koat 102 Rust Inhibitive.

Product Data

Vehicle: 100% Acrylic Resin
Solvent: Water
Flash Point: None
Drying Time: 4 hour to touch (77°F & 50% relative humidity) 12-24 hours to re-coat
Elongation/Tensile @ 77°F: Initial Elongation- 350% Tensile Strength – 270 psi
Weight per Gallon: 10.6 lbs
Solids-Weight: 57%
Solids-Volume: 45%
Colors: White and Custom Colors
V.O.C.: 0.54 lbs/gal
Environmentally Friendly
Keep Out of Reach of Children
Product will freeze below 32°F (0°C)


Surface must be clean, dry and free of dirt, grease and mildew. Remove any trace of mildew by washing with a solution that kills mildew spores. Old coating or residue that is loose or peeling must be removed by scraping, sanding, wire brushing or pressure washing. Avoid using cleaners with built-in wax or silicone additives since this may affect coating bond. Make any necessary repairs or replacements to damaged or leaking roof material. Rusty metal surfaces should be primed with the proper material, see Metal-Koat 102, Rust Inhibitive. If repairs are needed, please refer to “Go Green Roof Repair”.

IMPORTANT: Where ponding water conditions persist beyond 48 hours, roof drains or other corrective measures must be installed to eliminate water build-up prior to coating the roof.


Maximum adhesion and durability is achieved only when the surface is clean, dry, and properly prepared. Slope for positive drainage is recommended for any roofing application. Apply 1 gallon per 100-150 square feet with 2 coats minimum required. Highly weathered surfaces may require additional coverage. Apply with a brush, roller (1 1/4″ Nap), or spray equipment (Airless Sprayer- flow output 1 gpm, minimum pressure 3000 psi, tip size 0.0623(minimum)). Drying time is retarded by very high humidity. Do not apply at temperatures below 50°F. Coating should have ample time to surface dry before evening dew sets or it is rained upon.


Clean brushes, rollers, spray and other equipment immediately after use with hot soapy water.