The GOAT Solar Retrofit — Solar-Reflective Coating for Existing Bituminous Roofs
Most flat roofs in Britain are bituminous — built-up felt, torch-on or mineral cap sheet — and most of them are ageing, dark, and baking in every hour of summer sun. You don't have to strip them off to fix that. The GOAT Solar Retrofit is a waterborne, solar-reflective cool roof coating applied straight over an existing bituminous roof — reflecting the sun, protecting the old membrane and adding a seamless waterproof surface. A genuine retrofit, cold-applied in a single visit, with no torch and no tear-off.
A cooler roof, measured in the rooms below
A dark bituminous roof in summer can run 40–50°C hotter than the air around it — and every degree ends up in the top-floor rooms. A white, high-SRI surface bounces most of that radiation back before it becomes heat. With a Solar Reflectance Index of 112, The GOAT Solar Retrofit keeps the surface markedly cooler than the tired dark felt it covers — easing summer overheating, cutting cooling loads, and taking the daily thermal punishment off the membrane so the whole roof lasts longer.
Primer, reflective membrane and washable finish — in one
Ageing bituminous roofs bleed oils and carry decades of grime, which is why most coatings fail on them. The GOAT Solar Retrofit is built for exactly that substrate: an integrated primer that blocks oil and contaminant migration, a reflective base coat that flexes with the roof, and a washable finish that holds onto its reflectance instead of greying out in a season.
Goes straight over your existing bituminous roof
Built-up felt, torch-on, mineral cap sheet and ageing bituminous roofs — where the roof is sound, The GOAT Solar Retrofit bonds over it with no strip-off, no landfill and no hot works. It's the least disruptive way to cool and protect a roof that still has life left in it.
Spray, roller or brush across deck, upstands, plant bases and pipework in one continuous membrane.
Solvent-free, low-odour and non-flammable — well suited to occupied buildings.
Over 3 MPa adhesion and 120% elongation — it grips the substrate and moves with it.
A protective, reflective, watertight overlay that extends the life of what's already there.
Prepare · Apply · Protect
Assess and prepare the existing roof, prime, then two coats of The GOAT Solar Retrofit in solar reflective white — thickness verified with a wet film gauge, a minimum 1 kg/m² adjusted for how thirsty the old surface is. Cold-applied, touch dry in around 60 minutes, tools cleaned with water. It sits alongside our Solar Reflective Roofing and Roofing & Balconies systems.
An honest word about reflective coatings. A reflective roof is not a substitute for insulation — if anyone tells you white paint replaces PIR, walk away. Its wins are specific and real: buildings that overheat in summer, plant rooms and top floors that cook, big dark industrial roofs chasing cooling costs, and any ageing bituminous membrane you want to protect from UV. In winter the effect on heating is small. And it's a protective, surface-waterproofing overlay over a sound roof — splits, failed laps and ponding are treated first.
Technical characteristics
| Characteristic | Value / comment |
|---|---|
| Colour | White |
| Base | Waterborne acrylic dispersion |
| Solar Reflectance Index (SRI) | 112 |
| VOC content | 0 g/L |
| Application temperature | +5°C to +30°C |
| Minimum total consumption | 1 kg/m² (adjust for porosity) |
| Touch dry at 20°C | ≈ 60 min |
| Adhesion (tensile) | >3 MPa |
| Elongation at break | 120% |
| Service temperature range | −20°C to +60°C |
| Liquid water permeability | W3 – Watertight |
| Abrasion / washability | Washable, Class 1 |
| Packaging | 18 kg pail · pallet of 33 × 18 kg |
FAQs
Can it really go straight over my old felt roof?
Yes — that's what it's designed for. The roof needs to be sound, clean and dry, with any splits, failed laps or ponding treated first. The built-in primer handles the oils and contaminants that come off ageing bitumen. We assess every roof before recommending it.
How much cooler will the roof be?
A white, high-SRI surface reflects most of the sun's energy instead of absorbing it, so the coated surface runs markedly cooler than the dark felt it replaces — the hotter and sunnier the exposure, the bigger the difference, and the more it's felt in the rooms directly beneath.
Does it replace insulation?
No. It reduces solar heat gain and protects the membrane; insulation still does the insulating. The two work together.
Will it stay white?
Like any roof it weathers and collects dirt, which reduces reflectance over time — an occasional wash restores most of it. The waterproofing performance doesn't depend on the colour staying showroom-fresh.
Is it messy or smelly over an occupied building?
It's waterborne and solvent-free with 0 g/L VOC — low-odour and non-flammable, with no torch or hot works — which makes it well suited to occupied and sensitive buildings.
Reflect. Protect. Perform.
Send us your roof details or drawings and our technical team will tell you honestly whether The GOAT Solar Retrofit is right for your building.
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