COLORBOND steel and ZINCALUME steel are thermally efficient roofing materials, radiating less heat into your home as they cool down faster at night. Lighter coloured roofs, irrespective of material, reflect more heat than darker shades. The result of this being less heat available to be radiated into your home. To reduce the transmission of heat into a building, insulation can be easily incorporated during the installation of the steel roof sheeting. There are two types of insulation commonly used during the installation of steel roof sheeting. They are: – Reflective foil, commonly referred to as ‘sarking’: Reflective foil laminates which are commonly used to provide heat insulation under roof sheeting can serve a dual function as a vapour barrier, simply by thoroughly sealing the foil overlaps with moisture impervious adhesive tapes. The laps should be about 100mm and kept in close contact when positioning the laminate so the tape can be readily applied. The laminate must be allowed to drape between the roof supports so the cold temperature of the roof sheeting will not be transmitted to the laminate by contact. If this were to happen condensation could form on the underside of the laminate and may drip into the ceiling space. – Combined foil and glass/wool insulation blanket: This blanket should be installed over the battens with the glass/wool insulation facing up in temperate zones and facing down in tropical zones. For advice appropriate to your area, please phone BlueScope Steel Direct on 1800 022 999. There should be no sagging between battens to avoid air spaces between the fibreglass and the underside of the roof sheeting. This information is intended as a guide only.