White roof membrane: that's why it stays cooler inside
A flat corrugated iron roof in July is not a nice place to stand. The dark surface absorbs the sunlight, and the heat does not stay on the roof. It wanders down through the structure and into the rooms just below, where it lingers well into the evening.
That's why a dark roof gets so hot
A black surface absorbs almost all the sunlight that hits it. On a clear summer day, a dark roofing felt roof can reach over 70 degrees, even if the air around it is 25. A white surface does the opposite: it throws a large part of the light back again before it has time to turn into heat in the roofing felt.
That is the whole idea behind white roof membrane. Same membrane as the black one, same seal, just in a color that reflects the sun instead of receiving it.
What it means inside
The difference is most clearly felt where there is not much between the roof and the head: warehouses, workshops, garages, carports, conservatories, summer houses and allotment houses with flat roofs. If there is neither an attic nor significant insulation, the heat from the roof goes almost directly into the room.
These are also the places where air conditioning is rarely an option. A hall of 400 m² cannot be cooled with a split unit, but you can avoid heating it from above.
It solves two things at once
It is worth noting that the white membrane is not just a color. It is the same silicone-based roof membrane as the black one, with the same properties:
- Seamless and elastic surface without joints, 100% waterproof
- Up to 40 years of service life and 25 years of product warranty
- Resistant from minus 40 to plus 90 degrees, with enhanced UV protection
- Apply by roller or brush in one layer, directly on top of the existing roof
You therefore get the sealing and the cooling effect in the same work step. The roof must be cleaned and sealed anyway, and it does not cost extra to choose the color that also keeps the heat out.
Before and after on a corrugated iron roof
This is what it looks like on a regular corrugated iron roof, before and after.
When does white make the best sense
White is the obvious choice on flat roofs and roofs with a low pitch, where the sun is almost vertical on the surface for most of the day. The same applies to steel roofs and eternit roofs, which conduct the heat on quickly, and all buildings where people work or sleep directly under the roof.
If, on the other hand, the roof sits above a well-insulated attic, where the heat does not reach down anyway, the color is mostly a matter of appearance. The black one works just as well there.
This is how you calculate on your own roof
One 20 kg bucket covers up to 13.3 m² in one layer. A roof of 100 m² therefore corresponds to 8 buckets. You can enter your m² on the product page and see the price immediately, without having to do the math yourself.
See white roof membrane and calculate the price of your roof
You can find the white membrane on the product page for ours liquid roof membrane, where you can also calculate consumption.
