Research conducted in Australia and abroad on household energy consumption has uncovered interesting results for the roofing industry, according to Bristile Roofing.
They note the roof is one of the largest external facing surfaces of a home and the choice of roofing material has a major role in determining internal living temperatures and household energy usage.
Solar reflectance measures the amount of solar energy that is reflected back into the atmosphere after coming in contact with a given material, with the amount of solar energy reflected remaining the same strength as when it hits the material’s surface.
Solar absorption refers to the amount of solar energy that is transmitted into the material itself and is used as a measure to determine the amount of heat and cool energy transmitted though the building materials into the internal living areas.
Bristile says research conducted in the USA comparing (white) roof tiles and (white) metal roofing showed that roof tiles have significantly higher reflectivity than metal roofing, reflecting a total of 75.4 per cent of solar energy. This is 7.8 per cent more reflection than metal roofing which reflected a total 67.6 per cent.
As solar energy moves though a given material, depending on the properties of that material it either dissipates or reduces in strength.
In thorough testing, cited by Bristile, concrete and terracotta roof tiles were found to cause the strength of energy being transmitted to dissipate significantly.
Due to the high thermal mass of a roof tile, any heat that is absorbed dissipates as it transfers through the material, is stored and gradually released at night when the climate is cooler.
Commenting on the research Michael Monro, marketing and sales coordinator at Bristile Roofing, said: “Roofing materials can make a valuable contribution to the overall thermal efficiency of the family home, keeping it cool in summer and warm in winter.”
“This research confirms the ability of roofing materials to minimise the need for artificial heating and cooling by reducing external temperature fluctuation. This impacts the internal temperature of the house which has important implications for the building industry and home buyers, as constructing an energy efficient home has never been so important.” he added.