Arabic version: طلاءات الأسطح العاكسة توفر تخفيفاً من الحرارة للمنازل الأسترالية

According to The Guardian, reflective roof coatings could help Australian households reduce heat entering their homes and lower energy use, particularly as hotter conditions raise cooling demands. Most Australian house roofs are metal or tiled, while many apartments have concrete roofs; the majority are medium to dark in colour despite lighter surfaces generally reflecting more heat.

Nic Jacobsen, an Adelaide engineer, said upstairs rooms in his two-storey home had become unbearably hot even while a large air-conditioning system ran at full capacity. He upgraded insulation but still felt heat radiating through the flat metal roof and walls. After applying a heat-reflective coating to the roof and wall, he said the reduction in heat entering the upstairs area was immediate, although he could not quantify the savings.

Shane Strudwick, who distributes the Super Therm coating used by Jacobsen, said the water-based ceramic paint was developed by Nasa for the space shuttle and repels infrared radiation. In a basic Adelaide trial on a 22C day, Strudwick said untreated concrete tiles reached 60C by 1pm, compared with 26C for tiles given one coat. He said coating costs can generally be recovered through lower energy bills in three to five years, depending on the surface and household energy use.

University researchers have found that coating an otherwise functional roof can deliver energy savings and extend the roof’s life. Western Sydney University’s Prof Sebastian Pfautsch said reflective coatings should come before solar panels or improved insulation, arguing that photovoltaic systems work less efficiently when they become too hot. University of Sydney Prof Chiara Neto said a roof coating is among the most efficient, low-cost cooling retrofits and could save up to 40% of an energy bill in older, poorly insulated buildings with dark roofs.

Neto said reflective coatings need not be white, allowing homeowners to limit glare for neighbouring buildings. She added that widespread treatment of roofs could lower a suburb’s air temperature by two or three degrees by preventing surfaces from becoming hot. Pfautsch also warned that not every product meets its claims, noting Dulux paid a $400,000 penalty in 2016 over unfounded temperature-reduction claims for two paints.