How Much It Costs to Install Roof Insulation in Australia

How much roof insulation costs in Australia
Looking to insulate your roof and wondering how much it will set you back? Check out our guide to roof insulation costs below or get in touch with our team of experts for more tailored advice.

What Does Roof Insulation Cost?

HireTrades estimate that the average cost of insulating a 100 square metre roof is around $1,100 to $5,200. The truth is, the final cost will depend on a number of factors, including:

Climate and R-value

The R-Value of an insulation product indicates how effective it is at preventing heat loss and gain. Products with a higher R-Value will be more expensive than lower R-Value options. For example, you can expect to pay around $6-$8 per square metre for R3.0 Knauf Earthwool ceiling batts compared to $14-$16 per square metre for R6.0 Earthwool ceiling batts. The table below shows the total estimated cost of insulation for a 100 square metre roof with Knauf Earthwool using different R Values.
R3.0 $650 – $690
R4.0 $840 – $860
R5.0 $1,300 – $1,400
R6.0 $1,500 – $1,600
Depending on the climate of where you live, you may need a higher R-Value to help regulate temperatures effectively. If you are renovating, you may also be required to meet certain R-Value standards according to local building regulations.

Size and Type of Roof

The larger the area you need to insulate, the more square metres of insulation you will need and the higher the installation costs will be. Accessibility to the roof space may also affect the installation costs. It may be possible to install roof insulation from the inside if there is enough crawl space, whereas roofs with no crawl space may require some of the roofing material to be temporarily removed. The type of roof you have may also affect the method and products used in the installation. If you’re not sure what’s best for your project, a professional can guide you through the right insulation for your roof.

Purpose and Goals

What you plan on using your roof space for may affect how you insulate it and therefore the final cost. For example, if you are simply topping up the existing insulation in your roof with new insulation, it might be cheaper than if you plan on using the roof space for storage or converting the attic into a liveable space. Attic conversions will require insulation in the ceiling as well as attic insulation between the roof joists to ensure the area is habitable and compliant with building regulations. You may also want to invest in acoustic insulation to stop noise being transferred to the rooms below.Read also: How to work out the cost of adding insulation to your attic.

Types of Roof Insulation

Some of the best roof insulation products in Australia include:

Reflective Foil Insulation

Reflective insulation products help reflect radiant heat from the sun away from your home, which can help prevent the roof space from overheating.Two of our most popular reflective insulation products are:

Roof Sarking

Most homes have a layer of roof sarking under the roofing material which acts like a second skin to the home and improves the overall R-Value. Heavy duty sarking for metal roofs will set you back about $215 per 80m2, while a similar product for tile roofs will cost around $240 for 80m2.

Glasswool Batts

Glasswool insulation is one of the most popular insulation materials because it is affordable and highly effective at preventing heat transfer. Glasswool batts are a type of bulk insulation, meaning they contain millions of tiny air pockets in their structure which break up the pathway of heat to slow down heat transfer. R4.0 Glasswool batts cost around $8-$10 per square metre. Some of our most popular glasswool products for roof applications include:

Polyester Batts

Polyester insulation is a slightly more premium bulk insulation product than glasswool. As it is made from 100% polyester and contains no breathable fibres, it is suitable for homes with dust allergies. R4.0 polyester batts cost around $15 – $20 per square metre. One of our most popular polyester product is:

Blanket Insulation

Blanket insulation is available in rolls of a single length, compared to insulation batts which come pre-cut. Some blanket roofing products come with a reflective foil layer to help reflect radiant heat. Foil-backed glasswool blanket insulation rated at R3.0 will cost around $11-$15 per square meter. Popular blanket insulation products:

Loose Fill Insulation

At Pricewise Insulation, we don’t recommend using loose fill insulation or spray foam insulation as it has a number of disadvantages compared to insulation types like batts and blankets. Read more Expanding foam vs insulation batts – Which is better?

Can You DIY Roof Insulation?

Some people decide to install roof insulation themselves in order to save on installation costs. If you have safe access to your roof space and know how to safely and correctly install the insulation, it’s possible to do it yourself. If you’re considering a DIY installation, be sure to check out our DIY insulation videos before you get started. Installing insulation in the roof can be a hot and dusty job and care should be taken to avoid any health and safety hazards. Keep in mind that insulation batts must not be compressed or have any gaps left between them when they’re installed. Hiring a professional can give you peace of mind that the job will be done to a high standard. Professional insulation installers can also help you get the best products for your application. Get a fast and accurate quote for roof installations in Melbourne or Sydney with Pricewise Insulation today.

Ready to Get Started? Order Your Insulation Online Today.

Whether you decide to do it yourself or hire a professional, installing insulation in your roof is a smart move that will benefit your home for years to come. Not only does roof insulation help keep temperatures inside comfortable year round, it’ll also improve the energy efficiency of your home and lower your energy bills. Ready to get started? Head to our online store to place an order for the products you need. Or give us a call on 1300 729 639 to discuss your project.

Featured ProductsBrowse All

10 thoughts on “How Much It Costs to Install Roof Insulation in Australia

  1. Bill Mathers says:

    Is there a process where Sisalation or some other insulation can be fitted to an existing colorbond roof that is only 18 months old. We have purchased an existing home 18 mths old that has ceiling batts but no sisilation or sililar between the co;orbomd and the Battons. It is very noisy with changes in temp as the suncomes outfrom behind clouds. Thanks in advance any help greatly appreciated

    • Pricewise Insulation says:

      Hi Bill,

      Thanks for your comment.

      You can retrofit a layer of Sisalation or Kingspan Air-Cell Insulation to the underside of the rafters to shield radiant heat away from the roof cavity space. The two products that we recommend are Kingspan Air-Cell Insuliner and Kingspan Air-Cell Retroshield. Feel free to contact us on 1300 729 639 if you have any more questions.


  2. jennifer Arnold says:

    I live in Tasmania, my house is 30+ years old and has no insulation or sarking in the tin roof. It’s a gable style roof and is about 116m2.
    We get frost and occasionally snow.
    What type of insulation would you recommend please? I’m on a tight budget.

    • Pricewise Insulation says:

      Hi Jennifer,

      Thanks for your comment! The easiest and most effective way to insulate your house would be to start by installing insulation batts on top of the plaster ceiling. I would recommend using a minimum of R5.0 in Tasmania.

      Feel free to contact us if you have any further questions, and we can run through a solution that will work for your application.

Leave a Reply

Your email address will not be published. Required fields are marked *

Reach out for a quote today