How do I retro-fit insulation correctly before plasterboard?

[WhiteWoolf]

Hi there, we have a raked ceiling in a small living room. The old plasterboard has failed due to water damage and a bad paint job a few years back. As there is no insulation between the ceiling and tiled roof, we have decided to retrofit insulation and new plasterboard over the top. We have installed the wall track and furring channel 90mm down from the existing ceiling as we wanted to retain as much of the exposed beams as possible. We have Bradford sound break insulation R2.5 which is 88mm thick. I've just realised that tucking the insulation behind the furring channel will create quite a gap between the insulation and new plasterboard. Should we run the insulation the other way between the furring channel and use some strapping to hold in place so the insulation is a tight fit between the plasterboard? What should we fix the strapping to? Thank you

[EricL]

Hello @WhiteWoolf 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your roof insulation.

Looking at your second photo, I believe that installing it vertically would be a better option and will produce less waste. There is currently a gap to the left of the insulating panel which you can fill with another panel by cutting one panel down. If you continue your vertical installation method the cut piece can then be used for the next gap. In regards to the insulation strapping, please allow us to double check with our supplier if there is a method of installation for steel furring channels.

Let me call on our experienced members @Dave-1, @Nailbag, @TedBear and @JoeAzza for their recommendations.

If you have any other questions we can help with, please let us know.

Eric

[Nailbag]

Hi @WhiteWoolf 

I stand to be corrected but I think how you have already installed the batts is fine. The batts will already be doing their job and having a small air gap between the batts and the ceiling plasterboard acts as another insulation barrier.

Nailbag