Flat Roof Sealants

For flat roofing applications, moisture-cure silicone roof sealants are widely considered optimal because they do not break down under standing ponding water. Solvent-free silicone creates a seamless barrier that withstands severe weather and ultraviolet radiation. Alternatively, elastomeric acrylic sealants provide an effective solution for low-slope roofs with positive drainage, especially when paired with compatible bleed-blocking primers.

Yes, 100% silicone formulations like SiliconEx 500 are specifically engineered for permanent ponding water resistance. Unlike conventional water-based coatings that may re-emulsify when submerged under continuous standing water, moisture-cure silicone maintains its physical integrity and adhesion. This makes silicone sealants the preferred choice for flat roof sections, low-lying roof valleys, and areas around commercial rooftop drains.

Our flat roof sealants and coatings are compatible with a broad range of roofing surfaces. These include built-up roofing (BUR), modified bitumen, concrete, metal, wood, spray polyurethane foam (SPF), and single-ply membranes such as TPO and EPDM. For asphalt and bituminous substrates, applying a bleed-blocking primer like BleedEx 400 helps prevent bleed-through into topcoats.

Bituminous materials and asphalt-based built-up roofs contain oils that can leach into light-colored coatings. An acrylic bleed-blocking primer, such as BleedEx 400, seals the substrate to stop asphalt bleed-through from discoloring or affecting topcoats like silicone or reflective acrylic. It also promotes superior interlayer adhesion across the restoration system.

Drying and curing rates depend on the product formulation. For instance, SealEx 100 skins over within 4 to 6 hours and achieves a complete cure in 24 hours under standard ambient conditions. Proper curing ensures the elastomeric membrane develops its full 500% elongation and tensile strength before being subjected to heavy rainfall or topcoat applications.

Reflective topcoats, such as TropEx 310 and SolarEx 300, protect roofing membranes by deflecting ultraviolet and infrared radiation. Reflective coatings reduce heat absorption across the roofing envelope, lowering rooftop surface temperatures and reducing thermal stress. Formulations with high solar reflectivity maintain surface flexibility, resist dirt pickup, and prolong the overall functional life of the flat roof.