Ceiling Insulation: How Much is Enough?

Kitchen ceiling

How much ceiling insulation is protecting your home?
You might have a lot, a little or none at all – find out below.

Ceiling insulation is the most important insulation in your home, so it’s essential to know whether it’s doing the job it should be. Many people believe they have ceiling insulation, but in truth they haven’t been in their ceiling in years, or perhaps never!

Get to know how to properly insulate a ceiling and you’ll enjoy a much more comfortable home with lower heating and cooling bills too.

What Can Happen To Ceiling Insulation Over Time?

Settling and Compression
Insulation’s loft, or thickness, is what makes it work so well. If your insulation has settled over time, this will reduce how well it’s working. Sometimes insulation is squashed while maintenance is being carried out in the ceiling, or it could be pushed aside and not put back in place. Depending on what type of insulation is used, the material may be permanently flattened.

Complete ceiling coverage is essential to the performance of ceiling insulation. Loose-fill insulation, in particular, has a tendency to move over time, causing it to accumulate at the sides and leave the middle areas less protected. Ironically the middle areas of a room is often where households spend most of their time!

Rodents and Moisture
Your roof space may be home to any number of critters. Rodents in particular like to carry some varieties of insulation away as nesting material, leaving areas uninsulated. If your roof space is susceptible to moisture, you want to be sure that your insulation can withstand becoming wet (holding its shape while it dries), as this may affect its thickness and therefore how well it works!

Different Levels in Different Ceilings
Homes are often made up of multiple ceilings, accessed from different manholes in separate rooms. Often these separate areas have not received the same level of ceiling insulation, or the different areas’ conditions have made it react in a different way over time. This is particularly true if there have been renovations made to the home.

How Much is Enough?

An effectiveness of an insulation material is measured in terms of R Value, which stands for ‘Resistance Value.’ The Building Code of Australia specifies a minimum value for new home of R3.5 in the Melbourne area and R4.3 in colder areas of Victoria.

Measure the depth of your ceiling insulation and use this chart to see whether you have enough insulation in your ceiling.

What To Do About your Ceiling Insulation?

You don’t have to remove what you already have. You can enhance the R Value of your ceiling insulation by evening out what’s already there and installing a high quality bulk-insulation over the top.

Remember, what was considered the best ceiling insulation 20 or 30 years ago may not be the best today. Look for a product that will withstand the test of time – something that will hold its loft, springing back into shape when compressed.

Choose a type of ceiling insulation that will dry out after getting wet, and does not attract rodents.

We have been using and recommending polyester insulation for over a decade because it is extremely durable and highly effective.

Ceiling Insulation Batts

Are You Getting The Whole Picture of Your Home?

But remember, your ceiling isn’t the only thing influencing your home’s thermal comfort.

Your home is a system with many factors that determine how energy is used, or potentially wasted, when trying to keep it at a comfortable temperature.

ecoMaster’s unique whole-of-home approach ensures that all aspects of your home’s thermal comfort are considered. Our retrofit expertise spans: professional draught proofing, ceiling, underfloor and wall insulation; and secondary glazing, which is double glazing for existing windows.

When you’re in need of draught proofing providers and insulation installers in Melbourne, call ecoMaster on 1300 326 627.

Choose the right fit for your home!

You’ll enjoy the benefits of a prioritised home retrofit plan tailored specifically to your home and lifestyle. 

Book an ecoHome Assessment

9 comments… add one
  • Lillian Schaeffer March 24, 2016, 5:34 am

    This is some great information, and I appreciate your point that the best insulation from years ago might not be the best today. My husband and I just moved into an older home, so the insulation it has was installed probably fifteen years ago. We’ll definitely look into adding more and evening out what’s there to increase our house’s energy efficiency. Thanks for the great post!

    • ecoMaster March 24, 2016, 7:38 am

      Our pleasure, Lillian. Best of luck with making your home comfortable. If there is any way we can support you in upgrading your ceiling, please do get in touch.

  • GEORGE DRUMMOND July 24, 2016, 7:29 pm


  • Braden Bills January 18, 2017, 2:37 am

    I didn’t know that ceiling insulation could settle and move. It makes sense that I would need to take good care of it! Maybe I should have it replaced.

    • ecoMaster January 19, 2017, 12:43 pm

      Thanks for your comment Braden.
      Yes certain types of insulation will settle – particularly blown in cellulose.
      Many householders have no idea what kind of insulation is in their attic space and what condition it is in.
      Good quality insulation, installed well, makes a huge difference to the comfort of your home in summer and winter
      (as well as reducing your energy bills!)

  • Annah Kaspar July 20, 2019, 11:03 pm

    My home has a flat roof with no ceiling cavity. It was built in the 1970s. With these types of buildings what is the solution to top up insulation?

    • ecoMaster December 12, 2019, 8:49 am

      Hi Annah,
      1. If your home has ceiling lining under the rafters then there will be the thickness of the rafters (possibly 190mm) into which insulation can be fitted. The roof would need to be lifted for this.
      2. If the rafters are exposed inside then you can fit insulation between the rafters from inside and then line under the rafters with plasterboard.

      In either case you will have a better result using a combination of bulk insulation (polyester is awesome) and reflective insulation (such as Concertina Foil Batts) to achieve the max performance in a small space.

  • Alan December 11, 2019, 5:27 pm

    Hi ecoMaster,
    I was impressed with your article.
    Unfortunately I live near Newcastle.
    Do you know any companies with your skills in the Newcastle region

    • ecoMaster December 12, 2019, 8:45 am

      Thanks Alen, We will get one of our sales people to get in touch with you.


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