White Rubber Paint RAL 9003 — Cool Roof, Façade & Pool
White liquid rubber paint (RAL 9003) plays a different role from black RAL 9004 — primarily as cool-roof reflectivity, façade lightening, and pool coating. White's ability to reflect solar radiation can reduce roof surface temperatures by up to 30 °C compared to dark materials, with measurable energy savings in summer. This page covers where white earns its place and what the technical implications are.
The cool-roof effect
Solar Reflectance Index (SRI) measures how much sunlight a surface reflects. Black RAL 9004 has an SRI of about 0–5; white RAL 9003 measures 60–80. The difference translates into surface temperature reductions of 25–35 °C on hot summer days.
For flat roofs in the UK, that means:
- Lower roof surface temperatures — reduced thermal stress on the substrate
- Lower attic space temperatures — knock-on benefit to interior comfort in non-air-conditioned UK homes
- Slower coating UV degradation — white pigments deflect rather than absorb UV
- Up to 14 % cooling load reduction in studies of air-conditioned commercial buildings
Where white RAL 9003 works best
- Flat roofs in cool-roof mode — particularly on south-facing dwellings and commercial premises
- Façade lightening — refresh tired render with bright modern white
- Swimming pools — traditional white pool interior
- Garden walls and trellis — bright reflectivity in landscape design
- Indoor wet rooms — bathrooms, basement utility spaces — Class 1 EN 13300 abrasion resistance
Specifications and notes
| Property | Value |
|---|---|
| RAL code | 9003 (signal white) |
| Finish | Bright matte |
| SRI (Solar Reflectance Index) | 60–80 |
| Coverage per coat | 100–200 g/m² |
| Cool-roof temperature reduction | 25–35 °C peak vs dark surface |
Application notes for white
White shows dirt and surface flaws more than any other colour, so substrate prep matters more:
- Clean substrate thoroughly — every dark spot will show through the cured film
- Two coats minimum; a third for complete colour coverage on dark substrates (old bitumen, dark concrete)
- Apply in shaded conditions where possible — direct UV during application can cause uneven skin formation
Next steps
For black alternative see Black RAL 9004. For full pool application see the Pool coating landing page. Order white 6 kg direct from the product page.
RubberPaint Team
Technical editorial · RubberPaint
