When it comes to extending the life of your roof and safeguarding your home from water damage, elastomeric roof coatings have become an increasingly popular solution. These flexible, waterproofing sealants adhere to a variety of roofing substrates, filling hairline cracks, reflecting UV rays, and creating a seamless barrier against moisture intrusion. In this article, we’ll compare three leading brands—GAF, GACO, and American Standard Elastomeric Roof Coating —and explore how their elastomeric roof coatings help stop roof leaks, improve energy efficiency, and simplify maintenance.
What Is an Elastomeric Roof Coating?
Elastomeric coatings are water-based or solvent-based coatings, formulated with acrylics or polyurethanes, that cure into a rubber-like membrane. Key characteristics include:
- High Flexibility: Expands and contracts with temperature changes without cracking.
- Reflectivity: Many are white or light-colored to reflect sunlight, reducing heat gain.
- Waterproofing: Seals pinholes and hairline cracks in older roofing systems.
- Durability: Resistant to weathering, mildew, and UV degradation.
By forming a continuous, monolithic layer, elastomeric coatings can revitalize aging roofs, postpone tear-offs, and strengthen waterproofing performance.
Brand Spotlight: GAF Elastomeric Roof Coating
GAF’s Elastocoat™ is engineered for both commercial and residential flat roofs:
- Composition: Acrylic-based, waterborne formula.
- Coverage: Approximately 1–1.5 gallons per 100 sq. ft. per coat.
- Reflectivity: “Cool roof” white finish meets ENERGY STAR® guidelines.
- Cure Time: Dries to the touch in 1–2 hours; recoatable after 6–8 hours.
- Pros: Easy application with roller or sprayer; excellent crack-bridging; low odor.
- Ideal For: Modified bitumen, built-up roofing (BUR), concrete, and metal substrates.
Brand Spotlight: GACO Elastomeric Roof Coating
GACO’s ELASTO-COAT series emphasizes premium waterproofing:
- Composition: Solvent-based polyurethane/acrylic hybrid.
- Coverage: Up to 2 gallons per 100 sq. ft. in two coats.
- Elongation: Over 400% stretch capacity for dynamic roof movements.
- Adhesion: Bonds to most clean, dry surfaces without primer.
- Pros: Superior ponding-water resistance; fast recoat window; outstanding tensile strength.
- Ideal For: Roofs prone to standing water, complex details, and penetrations.
Brand Spotlight: American Standard Elastomeric Roof Coating
American Standard’s RoofGuard™ coating balances performance and value:
- Composition: Pure acrylic, 100% acrylic solids.
- Coverage: Typically 1 gallon per 80–100 sq. ft. per coat.
- UV Stability: Includes UV inhibitors to resist chalking and color fade.
- Maintenance: Can be cleaned and recoated throughout its lifespan.
- Pros: Budget-friendly; VOC-compliant; good mildew resistance.
- Ideal For: Residential low-slope roofs, DIY projects, and moderate climates.
Why Waterproofing Sealants Are Essential
Beyond aesthetic refreshment, an elastomeric roof coating acts as a sealant that:
- Prevents Leak Formation: Fills micro-cracks before they widen or allow moisture ingress.
- Reduces Thermal Cycling Stress: Reflective coatings lower surface temperatures, reducing expansion/contraction cycles that cause fatigue.
- Minimizes Maintenance Costs: Extends intervals between expensive repairs or full replacements.
Roof leaks often start as tiny fissures around flashings, seams, and fasteners. A properly applied elastomeric coating creates a seamless membrane that bridges these vulnerable points.
Application Tips for Lasting Performance
- Surface Preparation: Pressure-wash to remove dirt, chalk, loose coatings, and biological growth.
- Dry Conditions: Apply only when surface and ambient temperatures are above 50°F (10°C) and no rain is forecast for 24–48 hours.
- Multiple Coats: Two coats are standard—first as a primer/“bond” coat; second as a full waterproofing layer.
- Proper Thickness: Follow manufacturer’s mil-thickness guidelines (usually 20–30 mils per coat).
Attention to detail during prep and application is just as important as choosing the right product.
Investing in a high-quality elastomeric roof coating from a reputable brand like GAF, GACO, or American Standard can dramatically extend the life of your flat or low-slope roof. By selecting the formulation that best matches your climate, substrate, and performance needs—and by following best practices for application—you’ll create a durable, energy-efficient, and leak-resistant roofing system that stands up to the elements for years to come.
