Insulation will work well if it’s installed correctly. The following tips will help you achieve the best possible performance from your insulation:
Do not compress bulk insulation. It must retain its normal thickness wherever possible. In cathedral ceilings make sure there is sufficient space between the roof and the ceiling lining for installing the recommended insulation without compressing it.
Keep bulk insulation dry at all times. Performance will be inhibited if the insulation becomes wet. Make sure packs are stored in a dry place before installation.
Avoid gaps in the insulation and make sure batts are firmly butted against each other, ceiling joists and wall frames. Even if only 5% of an area is left uninsulated, up to 50% of the potential benefits may be lost.
Reflective foil should be installed with a still air gap of at least 20 mm width next to the reflective surface. Tape up any holes, tears or joins in the foil.
Do not cover electrical cables and equipment with insulation. Keep insulation clear of wiring using an appropriate separator such as cardboard. Have them inspected by a licensed electrician to ensure the insulation has been installed safely.
Donot install insulation within 90 mm of hot flues or exhaust fans.
Do not put insulation over or around recessed light fittings. Leave a 25 mm gap around their perimeters.
Batts can easily be installed to a thickness greater than the ceiling joists. This need not restrict roof access as ceiling joists are usually still visible and the batts will usually return to their original thickness if walked on.
Insulate internal walls between the house and uninsulated spaces such as garages and storerooms.
Use perforated reflective foil in walls and under floors when building with porous materials. The perforations prevent water droplets from penetrating but allow vapour through so that the insulation can dry if it does somehow get wet. For example, this prevents rotting behind weatherboards or under timber floors.
