If not well insulated, our home can easily lose up to 40 per cent of heat through the roof and 20 per cent through the walls. Insulating your home helps you to maintain a comfortable temperature and reduce your bills. Insulating the walls and ceiling can provide many benefits:
- increased energy efficiency (reduce heat loss in winter and heat gain in summer)
- reduce your dependence on heating and cooling appliances
- improved comfort with better control over the indoor temperature
There are two main types of insulation.
Bulk insulation traps tiny pockets of still air within its structure to reduce the heat flow. Bulk insulation is available as batts, blankets and boards or as loose fill which is pumped or blown into the area. There's a range of insulating materials: polyester, natural or glass wool, cellulose fibre, or expandable polystyrene. Bulk insulation keeps the heat in and suits cooler climates best.
Reflective foil is a layer of foil backed by paper or plastic that will bounce the heat back by radiation. It needs to be in an enclosed space and has to stay clean to remain effective. Any dust settled on it will make a big difference to how it works. Reflective foil keeps the heat out and is more effective in hot climates. Ask an insulation retailer to help you choose the right type of insulation product for your home.
What to Do
Make sure your insulation installer is trained to meet relevant Australian Standards. They also have to certify your installation meets relevant Australian Standards. Have your wiring inspected by a licensed electrician to ensure it can be safely covered by insulation and ask about the mandatory clearances around light fittings and transformers. Insulation must have a safe clearance around:
- halogen downlights or extra low voltage (ELV) downlights
- electrical wiring installed before 1986
- a gas or combustion heater with a flue through the roof
- high intensity heating lamps
- other items such as home security alarms, exhaust fans or water heaters.
It should also fit snugly between ceiling joists (bulk insulation will expand to a natural thickness). For reflective foil, a still air gap of at least 25 mm is required between it and the associated surface. It should also be clear of recessed light fittings and exhaust fans.
What’s the R value?
The R value is a measure of a material's resistance to heat transfer (known as thermal resistance). The higher the R value, the greater the insulating effect and energy savings. The recommended R value will vary according to the climate. Talk to your installer about what’s best for you.