Insulation for today's homes

Insulating the home is no longer treated as an afterthought. When designing or renovating a dwelling it is now widely acknowledged, including by the Australian government, (www.yourhome.gov.au/passive-design/insulation) that insulation acts as a barrier to heat flow and is essential for keeping your home warm in winter and cool in summer.

The website also reiterates that a well-insulated and well-designed home provides year-round comfort, cutting cooling and heating bills by up to half.

Insulation and the NatHERS

But what of the insulation products themselves? What’s changed there? They have become quite high tech in their composition and, as such, form the backbone of our Nationwide House Energy Rating Scheme (NatHERS).

NatHERS is a national framework for the purpose of regulating how Australian homes are rated for their thermal performance.

For Melbourne, the NatHERS rating aims for an R value of between 4.6 and 5.1.

Bearing in mind that the higher the R value, the better the thermal performance Roofrite was involved in a project recently that wrapped the entire house from floor to ceiling in insulation.

This approach not only helped to maximise the dwelling’s R value and will minimise future heating and cooling bills for the resident but it also enabled savings on expensive double glazing.

Insulation Products

There is a large range of insulation products designed with specific purposes in mind. For this project we utilised:

Kingspan AIR-CELL Insulbreak 65
Bradford Gold Ceiling Batts
Bradford Gold Wall Batts, and
Kingspan AIR-CELL Permifloo

Working from the top down, Kingspan AIR-CELL Insulbreak 65 was between the Colorbond roof and roof battes. It was also installed under the external cladding at the rear of the property. AIR-CELL Insulbreak 65 has an R value in Summer of R2.7 and in winter R1.5 and is simple to install as it is a roll out product and can be cut and stapled into place and taped across the joins as can be seen in the image below.

For the roof cavity we installed Bradford Gold roof batts. They were laid over the ceiling battens prior to plaster being installed. Bradford Gold batts have an R value of between R2.5 and R4.1. Apart from their thermal benefit, the ceiling batts help muffle the noise of heavy rain on the metal roof.

Next were the walls. These were lined with Bradford Gold wall batts. Wall batts are available with R ratings from R2.0 to R4.0. As with the ceiling batts, a side benefit is that external noise is reduced by the inclusion of batts in the walls.

Finally, insulation was installed under the timber floorboards. As much as 15-20% of winter heat loss and summer heat gain is through the floor. Kingspan’s AIR-CELL Permifloor is designed specifically for suspended framed floor applications and is perforated with tiny holes that allow water and vapour to permeate through. This prevents moisture collecting under the flooring - a little known problem that occur when using conventional underfloor insulation systems.