Cool roofs

A dark flat roof absorbs most of the sunlight that hits it and can pass 80°C on a sunny day. A cool roof does two things: it reflects most of the solar energy back, and it releases the heat it does take in rather than holding it. The result is a roof surface that runs far cooler in the same conditions, and a cooler building below. Across a town, lots of cool roofs also help cut the urban heat island effect and the energy used to fight it.

• SRI ~109

  Solar Reflectance Index (0 = black, 100 = standard white; higher is more reflective)

• 86%

  of solar energy reflected

• 80°C to under 30°C

  roof surface temperature in testing

• 11–27%

  lower cooling energy (US EPA)

• up to 60%

  bifacial solar output uplift

Sources: manufacturer testing; US EPA cool roofs guidance (epa.gov).

• A cooler building. Less heat passing through the roof means less overheating below, which matters most on top floors, in warehouses and anywhere that gets hot in summer.
• Lower running costs. On air-conditioned premises a cooler roof reduces the load on the cooling system and the energy it uses through the summer.
• A longer-lasting roof. Less heat means less daily expansion and contraction, so the waterproofing ages more slowly and needs less attention.
• Better comfort. Cooler, steadier conditions for the people, and in agricultural buildings the animals, underneath.
• Works with solar. A reflective surface keeps the roof zone cooler around an array, and bifacial panels use the light reflected off the white roof below them.
• Greener. Cooler roofs cut the urban heat island effect and the carbon that comes with extra cooling.

QLR ONE suits buildings that need temperature control and energy efficiency, for example:

• supermarkets and food warehouses
• cold stores and chilled distribution
• pharmaceutical warehouses
• production plants
• shopping centres
• residential blocks
• agricultural and livestock buildings
• holiday lets and cabins
• roofs carrying solar panels

On a small, shaded roof the effect is smaller and a standard finish may be all you need. An honest survey will tell you whether a cool roof is worth it for your building.

QLR ONE is the HYDRONYLON system finished in white. It is liquid-applied and cures into one seamless, reflective surface, with the joints and details that usually leak first reinforced as part of the system. Because it goes straight over a sound existing roof, you get full waterproofing and a cool, reflective finish in one job, without tearing the old roof off. It suits felt, metal and PVC roofs and is applied cold, so there are no hot works and the building can usually stay in use during the work.

QLR ONE is part of the HYDRONYLON system, assessed under European Technical Assessment ETA-23/0735 and installed only by HYDRONYLON Approved Contractors, who issue a 10-year product guarantee on the materials.