Share
Welcome to the Bunnings Workshop community @dug. It's terrific to have you join us, and many thanks for your question about insulating a patio roof.
You might like to check out some of the previous discussions our members have started on this subject. Plenty of info to glean there.
- How to insulate a metal roof? by @bowmatty
- How to stop condensation on patio roof? by @condruss
- How to add insulation to a sunroom with a colourbond roof? by @garyw
- How to insulate a patio roof? by @dingo22
- How to insulate Colorbond patio? by @tanmaried
When considering insulation under a galvanised iron roof, it’s important to remember that any insulation you add will increase the weight on the existing structure. Anything with substantial weight should really be run past the manufacturer to make sure the roofing system is designed to handle it.
A lightweight option is Foilboard insulation, which many members in the community have successfully used in similar outdoor areas. It’s relatively easy to cut and install, and being light it doesn’t put much extra load on the roof.
Since you’ve got a fair bit of depth in your beams, another alternative is to install insulation batts. These provide a much higher insulation value than foam sheets but would mean the insulation is visible underneath. To finish it neatly and protect the batts, you could fix wet area plasterboard to the underside of the ceiling. This not only improves the look but also gives you far better insulation performance overall.
Which way you go really depends on how much effort you want to put in, and how much heat transfer you’re looking to reduce. If you do decide to add plasterboard and batts, it’s definitely worth checking with the manufacturer first to ensure the structure can safely support that extra weight.
Allow me to tag @Nailbag, @Dave-1, @Jewelleryrescue and @Noyade to see if they have any advice to offer.
A note to our New Zealand readers: Foil insulation products are prohibited from use.
Please let me know if you have any questions.
Mitchell
