A bare concrete or dark membrane roof reaches 70–75 °C on a July afternoon in Dubai. A high-albedo white coating reflects most of the incoming solar radiation and re-emits much of what it absorbs, and the same roof settles around 45 °C. Put a thermal camera on it and the before-and-after is spectacular.
The honest number
Here is the part the industry skips. The fraction of heat absorbed by a roof that actually reaches the room below is not large — it is set by the ratio of the roof’s thermal transmittance to the outside surface heat transfer coefficient. On a Dubai villa built to the 2011 Green Building Regulations, that fraction is about 2–3%. Everything else goes back out to the sky and the air.
| 250 m² villa, 135 m² roof | Built 2011 or later | Built before 2011 |
|---|---|---|
| Surface temperature drop | ~25 °C | ~25 °C |
| Electricity saved per year | 446 AED | 965 AED |
| Share of the bill | 3.2% | 6.9% |
| Payback on savings alone | about 27 years | about 12 years |
Cooling a surface by 25 °C sounds like it should transform a bill. It does not, because the roof was never letting most of that heat through in the first place. If your villa is older, with little or no roof insulation, the same work returns roughly twice as much — but it still does not compete with window film.
Two systems
Aliphatic polyurethane — Certified line
A two-coat liquid-applied membrane, UV-stable, seamless over parapets and penetrations. Ten-year written waterproofing warranty. This is what we fit when the roof has to work as a roof: 80 AED per m² of roof area.
Acrylic elastomeric — Essential line
Water-based, high solar reflectance, considerably cheaper at 52 AED per m². It holds up well on a sound substrate but is less tolerant of ponding water and of movement at joints. We fit it where the roof is already sound and the aim is reflectance rather than waterproofing.
What the work involves
- Pressure wash and mechanical removal of loose or chalking material.
- Crack and joint treatment, primer where the substrate demands it.
- Two coats, cross-applied, with the second laid at right angles to the first so pinholes in one are covered by the other.
- Cure time between coats is the one hard constraint on our two-day schedule — the crew works the glass and the doors while the first coat sets.
Reflectance degrades with dust, which in Dubai is not a small factor. Expect to lose some performance in the first year and to recover most of it with a wash. We include the first clean.
What we do not claim
- No R-value. A coating is a fraction of a millimetre thick. It changes the roof’s reflectance, not its thermal resistance. Any product sold as “insulating paint” with a quoted R-value is making a claim that cannot be supported by independent testing, and we do not use them.
- It does not replace roof insulation. If your roof genuinely has none, insulation under the slab or above it will do far more than any coating.
- It does not cool a room by 5 °C. It reduces the heat flux into the top floor. With the AC running, you notice it as the system cycling slightly less, not as a dramatic change in comfort.
The full ranking of every measure we offer, by payback rather than by drama, is on how to cut a DEWA bill. Rates are on the pricing page.