How to check your ceiling insulation

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

Effective ceiling insulation is the best barrier against the summer heat and the winter cold. Most Victorian homes already have some form of ceiling insulation, however, if it has been in your roof for a while it may not be performing as well as it could.

Step 1: Safety first

Installing ceiling insulation

Go up into your roof space to see how much insulation you have and what type of insulation it is. There are inherent dangers associated with going into your roof space, so it is important to ensure you have someone to hold the ladder when you enter the ceiling space.

Step 2: Check the insulation levels

Think about adding extra insulation, especially where the insulation has settled or been moved. Some ceiling insulation can lose its effectiveness as it settles and compacts over time, so check whether it needs to be topped up or replaced altogether. Measure the height of your existing ceiling insulation. If it is less than 50mm thick it should be topped up. Use the table below to estimate the R value required for your ceiling.

Existing roof insulation
Minimum recommended R value of top up to achieve total R value of 3.5
Recommended R value of top up to achieve total R value of 5.0 
Blow-in insulation
This assumes an R Value of 0
R3.5 R5.0
Less than 50mm of insulation
This assumes an R Value of 0
R3.5 R5.0
50 – 100 mm of insulation
This assumes an R Value of 1.5
R2.0 R3.5

Step 3: Install ceiling insulation

Once you have established the amount of insulation you need to top up, you can find out how to install ceiling insulation

Tips

Installing insulation carries potential risks and requires expert knowledge. Find out more about insulation health and safety.