Henry SolarFlex 287: The 72% Reflectance Solution for Montana's Temperature Extremes

Henry SolarFlex 287 delivers where it counts — maintaining 72% solar reflectance after 3 years when other coatings have chalked out and failed. This water-based acrylic elastomeric coating tackles Montana’s brutal temperature swings with the flexibility to handle whatever Mother Nature throws at your roof.

Energy Performance That Pays Back

The numbers don’t lie. Initial solar reflectance of 0.86 drops to 0.72 after three years of weathering — still reflecting nearly three-quarters of the sun’s heat when competitors have degraded to gray chalk. This translates to real cooling cost savings, with the bright white finish providing excellent hiding power that reflects over 72% of the sun’s heat and UV rays after 3 years.

Energy Star certification and Cool Roof Rating Council approval mean this coating qualifies for utility rebates in many areas. The elastomeric formulation provides durability and UV protection while the reflective properties deliver genuine energy efficiency by reflecting sunlight.

The real-world impact? Interior temperatures drop by up to 20°F during Montana’s increasingly hot summers. For commercial buildings running AC units all day, that temperature reduction shows up directly in the power bill.

Application Specs for Real Jobs

Coverage calculations matter when you’re bidding jobs. Henry 287 covers 100 square feet per gallon on smooth surfaces, dropping to 66 square feet per gallon on rough surfaces — that’s 100 square feet per 1.5 gallons for textured substrates. Always figure two coats into your material calculation.

Specification	Value
Coverage (smooth)	100 sq ft/gallon per coat
Coverage (rough)	66 sq ft/gallon per coat
Application temperature	50°F - 140°F surface temp
Recoat time	Minimum 2 hours
VOC content	50 g/L maximum
Solids by weight	49% minimum
Solids by volume	38% minimum

The 50°F to 140°F surface temperature range works perfectly for Montana’s variable weather windows. Spring application when surfaces hit 50°F, or fall work when metal roofs are cooling below that 140°F threshold.

Application runs smooth with either airless sprayer or deep-pile roller in one direction, then apply the second coat at right angles after 2+ hours. Don’t thin the product, and avoid rain within 12 hours of application.

Built for Montana’s Climate Punishment

This coating maintains 150% elongation after 1,000 hours of accelerated aging — that’s the flexibility to handle extreme thermal cycling without cracking. Initial tensile strength starts at 150 psi minimum with 200% elongation, giving you a membrane that moves with the substrate.

The formulation resists disbonding, chalking, and mildew — critical when dealing with Montana’s wet springs and UV-intense summers at elevation. The 7-year limited warranty backs up these performance claims for one-time application.

Compatible substrates include asphalt emulsion, acrylic coatings, aluminum coatings, aged BUR/MB systems, and metal roofs. Skip this product for shingles, plywood, decks, uncoated SPF, rubber/PVC, or silicone-coated roofs.

Surface prep makes or breaks longevity — pressure wash with TSP, treat algae with bleach mix, ensure complete drying, then repair cracks and holes with Henry 289 Sealant and Henry 296 ElastoTape before coating.

FAQs

What’s the real difference between Henry 287 and the silicone 887?

Henry 287 requires 2 coats and carries a 7-year warranty, while the 887 silicone is a 1-coat system with lifetime warranty. The 287 can’t handle ponding water — the 887 can. Choose 287 for sloped roofs where water sheds properly. Pick 887 for flat roofs with drainage issues.

How does the coverage really work out on rough surfaces?

You’ll burn through 1.5 gallons to cover 100 square feet on rough surfaces versus 1 gallon on smooth. That’s a 50% increase in material cost that needs to show up in your bid. Factor this into quotes for rough BUR or heavily textured modified bitumen.

What happens if rain hits before 12 hours?

The manufacturer specifically warns to avoid rain within 12 hours. Fresh coating will wash off, creating a mess and wasting material. Check weather carefully — Montana’s afternoon thunderstorms can ruin a morning’s work.

Can this go over existing coatings?

Yes, over asphalt emulsion, acrylic, or aluminum coatings. But it won’t stick to silicone-coated roofs — that’s a complete tear-off situation. Test adhesion on a small area if you’re unsure about the existing coating type.