There are a lot of insulation products out there. Knowing which one is right for your project can be tricky, especially if you’ve got a budget to stick to.
We’ve put together a guide to the best roof insulation in Australia to help you find out what type of insulation you need, what R-Value is ideal and where to buy high quality, affordable insulation online.
If you need project-specific advice from an insulation expert, give the Pricewise Insulation team a call on 1300 729 639 and we’d be happy to discuss your options with you.
What Is Roof Insulation?
Roof insulation is a product that is installed under the roofing material to prevent the flow of heat. Along with insulation in other parts of the home, roof insulation helps keep indoor temperatures cooler in summer and warmer in winter.
Roof insulation is often confused with ceiling insulation. Sometimes the two terms are used interchangeably. Usually, ceiling insulation refers to insulation products that are installed between the ceiling joists whereas roof insulation refers to products installed below the roofing material.
If you are planning on converting the space between your ceiling and roof into livable space, check out our guide to the best kind of insulation for your attic project.
What Is a Good R-Value for Roof Insulation?
The most important factor you should consider when looking for the best roof insulation is the R-Value of the insulation product.
The R-Value indicates how effective it is at preventing heat loss and heat gain. The higher the R-Value, the more effective the insulation product is, and the more potential savings you can make on your energy bills.
Choosing the right R-Value for roof insulation is very important to ensure your home can regulate temperatures well all year round. There are guidelines in the Building Code of Australia outlining the minimum R-Values that should be installed based on where you live.
What We Recommend for Roof Insulation?
- For cooler climates such as Melbourne, Sydney and Adelaide, we recommend at least R5.0 or R6.0 for the roof.
- For warmer climates such as Perth and Brisbane, we recommend at least R4.0.
Bulk Vs Reflective Insulation – Which One Do You Need?
There are many different types of roofing insulation, the most common being bulk insulation and reflective insulation.
- Bulk insulation products (such as batts and rolls) have millions of tiny air pockets within their structure which break up the flow of heat. Batts and rolls are ideal when you want to reduce the conduction of heat flow between objects that are adjacent to each other.
- Reflective insulation usually consists of a foil layer backed by a paper or plastic layer. It’s used when you want to reflect radiant heat. For example, in hot sunny climates, reflective foil will reflect radiant heat from the sun away from your home.
More recently, roof insulation has been designed to incorporate both bulk and reflective insulation for highest performance and insulating capabilities.
What Is Roof Sarking – and Do You Need It?
Roof sarking is a pliable membrane that is installed directly under the roof tiles or metal sheets to help weather-proof the home. It’s usually made with a reflective foil layer which helps reflect radiant heat and increase the overall insulation of the home.
Most homes are built with roof sarking, but on its own sarking will not provide enough thermal regulation. Bulk insulation products are typically used between the roof or ceiling joists to achieve the right R-Value.
Read more: What is roof sarking?
What Is the Best Insulation Material for Roofs?
Roof insulation is made from a number of different materials, depending on whether it is bulk and/or reflective insulation.
The most common bulk insulation materials used are:
- Glasswool – made from recycled glass materials, highly durable and affordable.
- Polyester – excellent thermal properties, hypoallergenic and non-toxic with slightly higher price point than glasswool.
Foil insulation has a reflective surface which creates a radiant barrier against heat transfer from the sun. It is important that foil insulation is installed correctly to ensure its full insulating capabilities are reached. The R-Value (insulating power) of reflective foil insulation will depend on how it is installed and what climate you are living in.
Best Roof Insulation Brands in Australia
Pricewise Insulation stocks a wide range of Australia’s highest quality insulation products. We’ve listed some of our top performers below to help you start browsing your options. If you have any questions, don’t hesitate to get in touch and our team can help.
The top bulk insulation products include:
Roof foil insulation products available at Pricewise insulation include:
The following products combine both bulk and reflective insulation:
- Knauf Earthwool Roofing Blanket Roll
- Fletcher Permastop Building Blanket Insulation
- Bradford Anticon Roofing Blanket
Click through to the links above to find out more about the price difference between brands. For information about budgeting for your roof installation, check out our guide on roof insulation cost.
Video – Brand Comparison
Should I Buy Roof Insulation Batts or Rolls?
This depends on your own personal preference as well as the nature of your space. Both these forms of bulk insulation are equally effective at insulating. The main difference is the way in which they are installed.
Roll insulation can be ‘rolled’ out between the roof joists without needing to be cut into segments. This is especially useful for roof spaces that have few obstacles and a large space to work in (which are generally few and far between!).
However, if you have many obstacles and a small area, insulation batts may be a more appropriate option. As batts are pre-cut, they are easy to install and cut to fit any space.
Are You Retrofitting Roof Insulation or Installing During a New Build?
Insulation installers can install roof insulation in both new and existing homes. In some cases it may be possible to install new insulation over old insulation to boost the overall R-Value. If the old insulation is damaged, mouldy or infested it should be completely removed before the new insulation is installed.
Pitched Roof With a Flat Ceiling
For pitched roofs with a flat ceiling where there is crawl space, it may be possible to install insulation from inside the roof space. We recommend installing insulation batts in between the ceiling joists as well as installing sarking or foil batts beneath the roof to help with radiant heat.
Roofs With No Crawl Space
For roofs with no crawl space, for example if you are lifting a metal roof to install insulation, we recommend putting down insulation batts first on top of the plaster. Then we suggest putting down some sarking or Kingspan Air-Cell Insulation with the silver side up to reflect radiant heat away from the house.
For tailored advice about the best roof insulation for your project, give our insulation specialists a call on 1300 729 639 and we’d be happy to talk you through your options.
What Type of Roof Insulation Is the Most Energy Efficient?
A high R-Value means better insulating power and therefore greater energy efficiency. If your budget allows, we recommend upgrading to the highest R-Value you can afford for your roof insulation as this will lead to greater temperature control and higher energy efficiency in your home.
Keep in mind that to get the maximum effects of insulation, it’s important to insulate your entire home, not just one area.
Check out our guides to insulating other areas of your home:
- The best ceiling insulation for Australian homes
- The best kind of insulation for your attic project
- Choosing the right wall insulation
- Which underfloor insulation should you use?
- Which insulation is best for soundproofing a home?
Buy the Best Roof Insulation Online Today
Pricewise Insulation supplies a wide range of high quality, affordable roof insulation products which perform very well in Australian climates.
Order online today or email firstname.lastname@example.org to discuss your project with one of our insulation specialists.