FAQs

Frequently Asked Questions.

Residential FAQs

Insulation – how does it work?

Insulation acts as a barrier to heat flow and is essential to keep your home warm in winter and cool in summer. A well insulated and well-designed home will provide year-round comfort, cutting cooling and heating bills by up to half. This, in turn, will reduce greenhouse emissions.

Climatic conditions will influence the appropriate level and type of insulation you need in your suburb. Establish whether the insulation will be predominantly needed to keep heat out or in (or both). Insulation must cater for seasonal as well as daily variations in temperature. Please visit the Commonwealth Department of Climate Change & Energy Efficiency’s Your Home Technical Manual for types of insulation & how much you’ll need for your region in Australia.

Passive design techniques must be used in conjunction with insulation. For example, if insulation is installed but the house is not properly shaded, built up heat can be kept in by the insulation creating an ‘oven’ effect. Draught sealing is important, as draughts can account for up to 25 percent of heat loss from a home in winter.

The most economical time to install insulation is during construction.

Insulation – explain the terminology

Material R-valuesare supplied with bulk insulation and refer to the insulating value of the product alone.

Total (System) R-valuesshould be supplied with all types of insulation for intended applications. This is the actual performance level that can be expected when the insulation is installed.

R-valuescan differ depending on the direction of heat flow through the product. The difference is generally marginal for bulk insulation but can be pronounced for reflective insulation:

Up R valuesdescribe resistance to heat flow upwards (sometimes known as ‘winter’ R values).
Down R valuesdescribe resistance to heat flow downwards (sometimes known as ‘summer’ R values).

Where do I install insulation?

Roofs and ceilings work in conjunction when it comes to insulation.

Install insulation under the roofing material to reduce radiant heat gain.
Install insulation in the ceiling to reduce heat gain and loss. In most cases ceiling insulation is installed between the joists.

Veranda roofsshould be insulated in hot climates where outdoor living spaces are used extensively, to reduce radiant heat gain. Heat build-up under verandas not only affects the space below but can affect conditions inside the house.

Bulkheads(wall sections between ceilings of different heights) must be insulated to the same level as the ceiling, as they are subjected to the same temperature extremes.

Save up to 45 percent on heating and cooling energy with roof and ceiling insulation.

External wallsshould be insulated to reduce radiant, conducted and convected heat transfer. Wall insulation can be installed:

Within cavities.
Within stud frames.
On the outside of stud frames.
On the inside or outside of solid walls.

Does insulation act as a vapour barrier?

Depending on the particular situation, some forms of insulation can double as a vapour or moisture barrier.
Save up to an additional 15 percent of heating and cooling energy with wall insulation.