Henry SolarFlex 287 delivers what contractors need: reflects >72% of sun’s heat and UV rays after 3 years with a 7-year limited warranty. This water-based acrylic coating targets low-slope roofs that drain properly — not ponding situations. At 100 sq ft per gallon on smooth surfaces with two coats required, you’re looking at 50 square feet of finished coverage per gallon.
Performance That Holds Up
The numbers tell the story better than marketing claims. Initial solar reflectance: 0.86 drops to 0.72 after 3 years. That’s real-world aging data, not laboratory projections. The coating maintains 150 psi minimum tensile strength and 150% minimum elongation after 1000h aging.
| Specification | Value |
|---|---|
| Solar Reflectance (Initial) | 0.86 |
| Solar Reflectance (3-year aged) | 0.72 |
| Solids by Weight | 49% minimum |
| Solids by Volume | 38% minimum |
| Tensile Strength | 150 psi minimum |
| Initial Elongation | 200% minimum |
| VOC Content | 50 g/L maximum |
The 50°F - 140°F surface temperature range matters in Montana. You can’t apply this coating on a frosty October morning or a blazing August afternoon when the metal roof hits 150°F. Plan your application window accordingly.
Application Reality Check
Coverage varies by surface texture. Smooth surfaces: 100 sq ft per gallon per coat. Rough surfaces: 66 sq ft per gallon. Always figure on two coats — this isn’t a single-coat system like some silicone alternatives. Wait minimum 2 hours between coats, longer in humid conditions.
Preparation matters: Pressure wash with TSP, treat algae with bleach mix, ensure roof is dry. Repair cracks/holes with Henry 289 Sealant and Henry 296 ElastoTape. Mix thoroughly, apply with sprayer or deep-pile roller in one direction. Apply second coat at right angles after 2+ hours. Do not thin. Avoid rain within 12 hours.
Know What It Won’t Do
Henry 287 works on asphalt emulsion, acrylic coating, aluminum coating, aged BUR/MB, and metal. Skip it for shingles, plywood, decks, uncoated SPF, rubber/PVC, or silicone-coated roofs. Not suitable for ponding water — that’s what separates it from Henry’s 887 silicone coating.
The comparison to Henry 887 Tropi-Cool matters for contractors choosing between systems:
- 287 is acrylic (water-based) vs 887 is silicone (moisture-cure)
- 287 has a 7-year warranty vs 887 lifetime warranty
- 287 requires 2 coats; 887 is a 1-coat system
The Contractor Verdict
Reviews note easy application with roller or sprayer, good coverage but usually requires 2 coats for best results, and effective at reducing attic/interior temperatures. Must follow prep instructions (cleaning) strictly for longevity.
Henry 287 SolarFlex fills the gap between basic roof paint and premium silicone systems. The 7-year warranty reflects honest expectations for an acrylic coating. At roughly half the material cost of silicone alternatives, it makes sense for properly draining roofs where ponding isn’t an issue. Just don’t expect silicone-level performance from an acrylic coating — physics doesn’t work that way.
Frequently Asked Questions
Q: How much area does Henry SolarFlex 287 actually cover per gallon?
Henry SolarFlex 287 covers 100 square feet per gallon per coat on smooth surfaces, but requires two coats for proper application — so you’ll get 50 square feet of finished coverage per gallon. On rough surfaces, coverage drops to 66 square feet per gallon per coat, or 33 square feet finished per gallon.
Q: Can I use Henry 287 on a roof that ponds water?
No, Henry 287 SolarFlex is not suitable for ponding water situations. This acrylic coating requires properly draining roofs, unlike Henry’s 887 Tropi-Cool silicone coating which can handle ponding water.
Q: What’s the real-world reflectivity of Henry SolarFlex 287 after weathering?
Henry SolarFlex 287 starts with 0.86 solar reflectance when new but drops to 0.72 after 3 years of weathering. The coating maintains over 72% of the sun’s heat and UV ray reflection after 3 years, which is what matters for long-term cooling performance.
Q: How long do I need to wait between coats and before rain?
Wait minimum 2 hours between coats of Henry 287, longer if humidity is high. You need at least 12 hours of dry weather after the final coat — don’t start application if rain is forecasted within that window.
Q: What temperature range can I apply Henry SolarFlex 287?
Apply Henry 287 when surface temperature is between 50°F and 140°F. This means no frosty morning applications and avoiding hot metal roofs on summer afternoons when surface temps exceed 140°F.
Q: What surfaces can Henry 287 actually go over?
Henry SolarFlex 287 adheres to asphalt emulsion, existing acrylic coatings, aluminum coatings, aged built-up roofing (BUR), modified bitumen (MB), and metal roofs. It won’t work on shingles, plywood, decks, uncoated spray polyurethane foam, rubber/PVC membranes, or silicone-coated roofs.
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