Henry SolarFlex 287 is a premium water-based acrylic latex elastomeric coating designed for contractors tackling low-slope roof recoating projects. With 0.86 initial solar reflectance dropping to 0.72 after 3 years, this coating delivers measurable energy savings that matter in Montana’s temperature extremes. At 100 square feet per gallon coverage on smooth surfaces, contractors can calculate material needs accurately without the guesswork.
Energy Performance and Technical Specifications
The numbers that matter for Montana contractors start with heat reflectivity. SolarFlex reflects over 72% of the sun’s heat and UV rays after 3 years — not just when new, but after real-world weathering. That sustained performance translates to cooler buildings during Montana’s increasingly hot summers.
The coating meets both ENERGY STAR and CRRC (Cool Roof Rating Council) standards, backing up its energy claims with third-party verification. For contractors bidding commercial work, those certifications open doors.
| Specification | Value |
|---|---|
| Solar Reflectance (Initial) | 0.86 |
| Solar Reflectance (3 Years) | 0.72 |
| Solids by Weight | 49% minimum (ASTM D1644) |
| Solids by Volume | 38% minimum (ASTM D2697) |
| Tensile Strength | 150 psi minimum (ASTM D2370) |
| Elongation (Initial) | 200% minimum |
| VOC Content | 50 g/L maximum |
The elastomeric properties hold up under Montana’s freeze-thaw cycling. Initial elongation of 200% drops to 150% minimum after 1000 hours of aging — still flexible enough to handle substrate movement without cracking.
Coverage Rates and Application Requirements
Coverage depends entirely on surface texture. Smooth surfaces take 100 square feet per gallon per coat, while rough surfaces drop to 66 square feet per gallon. Since the product requires 2 coats, contractors need to double those quantities when calculating total material needs.
Application temperature range runs from 50°F to 140°F surface temperature — workable for Montana’s construction season from late April through early October. Minimum 2 hours drying time between coats means crews can complete a roof in a single day under good conditions.
The second coat should be applied at right angles to the first for complete coverage. Surface temperature must not exceed 140°F — rarely an issue in Montana but worth checking on dark roofs during peak summer.
Substrate Compatibility and Limitations
SolarFlex works on specific substrates only. Suitable substrates include asphalt emulsion, acrylic coating, aluminum coating, aged BUR/MB (Built-Up Roofing/Modified Bitumen), and metal. These cover most commercial recoating scenarios contractors encounter.
The unsuitable list matters just as much. Do not apply to shingles, plywood, decks, uncoated SPF (spray polyurethane foam), rubber/PVC, or silicone-coated roofs. That silicone incompatibility eliminates many newer commercial roofs — nothing sticks to silicone properly.
Surface preparation determines longevity. Pressure wash with TSP, treat algae with bleach mix, and ensure the roof is completely dry. Repair cracks and holes with Henry 289 Sealant and Henry 296 ElastoTape before coating application.
The 7-year limited warranty applies only when following manufacturer’s instructions. Henry recommends this as a one-time application — not a product for repeated recoating every few years.
Comparison to Silicone Options
How does SolarFlex stack up against Henry’s silicone options? Henry 287 (this product) is water-based acrylic with a 7-year warranty, requires 2 coats, and cannot handle ponding water. Henry 887 Tropi-Cool is silicone with lifetime warranty, single-coat application, and ponding water resistance.
For Montana contractors, the choice depends on roof drainage. Well-drained roofs save money with SolarFlex. Problematic roofs with ponding issues need the silicone despite higher material costs.
Installation Feedback
Contractors report easy application with roller or sprayer, though most jobs need the full 2 coats for proper coverage. The coating effectively reduces attic and interior temperatures, but surface preparation proves critical for long-term performance.
Do not thin the product — it’s formulated for proper flow and coverage as-is. Avoid rain within 12 hours of application, which means checking Montana’s afternoon thunderstorm patterns during summer application windows.
Frequently Asked Questions
Q: Can I apply Henry SolarFlex over existing roof coatings?
A: Yes, but only over asphalt emulsion, acrylic coating, or aluminum coating. You cannot apply it over silicone-coated roofs — nothing adheres properly to silicone surfaces.
Q: What’s the actual coverage I should expect on a typical commercial roof?
A: Plan on 100 square feet per gallon for smooth surfaces like metal roofs, or 66 square feet per gallon for rough surfaces like mineral cap sheet. Since you need 2 coats, double those material requirements.
Q: How long does the reflectivity last?
A: Initial solar reflectance of 0.86 drops to 0.72 after 3 years of weathering. That’s still reflecting over 72% of heat after real-world exposure to UV, dirt, and weather.
Q: Can I use this on residential shingle roofs?
A: No. SolarFlex is not suitable for shingles. It’s designed for low-slope commercial applications on specific substrates like metal, modified bitumen, and previously coated surfaces.
Q: What happens if rain hits before it’s dry?
A: The coating needs 12 hours minimum before rain exposure. Fresh coating will wash off if rain hits too soon, requiring complete reapplication of affected areas.
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