Insulate brick veneer walls

Last updated: 15 December 2021

Brick veneer is a wall construction technique that became popular in the 1960s and is still commonly used in new homes built today. This type of construction has a brick skin on the outside and a timber frame covered with plasterboard on the inside. Brick veneer walls have a timber frame covered with plasterboard internally and will sound hollow when you tap on them, whereas double brick walls will have a solid sound. Brick veneer houses built prior to 1990 are unlikely to have insulated walls.

Insulation tips for brick veneer walls

Select the right insulation

When adding insulation to existing brick veneer walls, there are a range of types of insulation that might be suitable for your needs. Check the product's R value: a measure of a material's resistance to heat flow (known as thermal resistance). The higher the R value, the greater the resistance to heat transfer, the greater the insulating effect and the greater the energy (and money) savings. The recommended R value for wall insulation is R2.5 in Victoria.

Ensure that insulation batts are less than 90mm thick

This will ensure that they will fit snugly within the wall frame. Be careful not to compress the batts as this will reduce their efficiency.

Consider loose-fill insulation

If you are not planning on removing any wall lining, specially treated loose-fill insulation can be pumped into the wall cavity. This could be installed by either drilling holes into the plasterboard from the inside, or drilling holes in between the bricks from the outside.

In some cases, you can also lift tiles or sheets of roofing to install the insulation from above the wall cavity.

Remember to check the health and safety tips for installing insulation.

Environmental credentials

Research the environmental credentials of your insulation product, and look out for products with low toxin levels.

Acoustic performance or Sound Transmission Class (STC) rating

Most insulation products will provide a certain level of sound reduction as well as thermal insulation, offering extra incentive to insulate your walls. Good acoustic performance could be important if you have a problem with external noise. Heavier insulation products, like rock wool, tend to have the best sound reduction performance for a given width.

Electrical wiring

Electrical wiring is often covered when insulation is installed. Seek advice from your electrician to ensure the wiring is suitable to be covered. Ensure any work the electrician does will not compromise the quality of the insulation installation. If you are using an installation company, it will usually arrange an electrician check and include the cost in the quoted price.

Questions to ask your builder

Installing insulation carries potential risks and requires expert knowledge. Poor installation of insulation will affect its performance and your potential cost savings, so it's important to ask the right questions of your installers.

National Standards and Codes of Practice

Various Australian standards and national codes of practice cover the installation of ceiling insulation products. For more information visit the Insulation Council of Australia and New Zealand (ICANZ) website.