How to install ceiling insulation

Ceiling insulation can save up to 20% on your heating and cooling energy costs.

Installing ceiling insulation will increase your overall comfort and reduce your long-term home energy costs.

Check the levels of ceiling insulation in your home to find out whether you need to top-up instead of installing new insulation.

Step 1: Select the right insulation

Ceiling insulation

For the Victorian climate the recommended minimum R value for bulk ceiling insulation is R3.5. In Victoria’s alpine climates there is a need for even higher levels of insulation. Aim for R5.0 to achieve greater comfort and energy savings in your renovated home.

Find out how to select the right insulation here.

Step 2: Select the right installer

When installing insulation in your ceiling it is recommended that you contact a trained professional who has the required skills and knowledge. Follow our tips below and ask your installer the right questions to ensure that your insulation in properly installed.


  • Allow clearance around hot flues, exhaust fans, appliances and fittings
  • Ensure that insulation has a minimum clearance of 50mm above incandescent lights
  • Install unvented LED lighting instead of halogen downlights to significantly reduce the required clearance around your ceiling insulation. Refer to the Australian/New Zealand Wiring Rules (Australian/New Zealand Standard (AS/NZS) 3000:2007) for more detailed information
  • Keep insulation materials containing reflective foil clear of electrical wiring and fittings and do not secure it with metal staples. An electrician will need to check your electrical wiring to make sure that it is suitable to be covered by insulation
  • Installing insulation carries potential risks and requires expert knowledge. Find out more about insulation health and safety .

Questions to ask

If using a builder or installer, it's important to check that they have a good knowledge of the relevant safety risks associated with installing insulation.

Q1: Is it possible to install the insulation in my home?

A: It may not always be possible to install insulation into all roof spaces with even coverage. The pitch of the roof may be too shallow, with heating or cooling systems and ducts blocking easy access. Ask your builder or installer if they think it will be possible to get access to your existing roof space.

Q2: Can your installer guarantee good coverage?

A: Some companies will undertake surveys with infrared cameras before and after installation to check that it has been properly installed or may provide this service as an optional extra. To be effective, the thermal imaging needs to be undertaken when there is a reasonable temperature difference between the inside and outside of the house – either on a hot summer day or a cold winter day when heating is operating.

Replacing your roof as part of your renovation?

During a major renovation, parts of the roof may have to be removed. This provides you with an ideal opportunity to install an insulation blanket paired with reflective foil, called foil-backed insulation, over the battens before laying down the roofing. The blanket will become compressed over the battens, but sag in between allowing you to create a cushioning air gap to provide further insulation. 

It is recommended that you install foil-backed insulation in your roof to R1.0 or higher. Installing foil-backed blanket insulation is also a great idea if you are building a flat roof or cathedral ceiling.

Insulation placement

More information

Various Australian Standards and National Codes of Practice cover the installation of ceiling insulation products. For more information on installing insulation visit the Insulation Council of Australia and New Zealand (ICANZ) website.