- The first step is to check your current insulation: is there any? What state is it in?
- Check what the R values are for your climate zone (see 'Building Code requirements' above).
- Make sure all leaks (roof and pipes) are repaired so the new insulation doesn't get wet. Damp insulation is less effective.
- Have an electrician check you can safely cover electrical wiring that can't be placed outside the insulation.
- If you have recessed downlights that are not closed abutted (CA) rated, replace them to eliminate the air gaps. CA rated recessed light fittings are now available that allow insulation to touch them. If you're not replacing the downlights, check to see how big a gap in the insulation is needed around each light fitting to prevent over-heating.
- Choose a product that is independently accredited and complies with the standard AS/NZS 4859.1: 2002. Compliance with this standard is mandatory under the Building Code. A compliance statement must be on the label of the insulation.
- Wear a dustmask, goggles, gloves, long sleeved shirt and closed footwear when installing fibre insulation products.
The quality of installation is of paramount importance. Even small gaps will undermine the performance of the insulation. A comprehensive easy-to-use guide on installing insulation is available as a free download from www.energywise.govt.nz.