Insulation for sliding shed roof

[Gadget4x4]

Hi - I'm considering building a small shed with a sliding roof as an observatory but have concerns about condensation on the roof. Would like to know what others have have done to help prevent droplets forming and falling on equipment such as insulation used or other means.
Cheers Peter

[glend]

I just used foil insulation from Bunnings. Cheap, held in place by wire strung across the roof members. Personally I avoid metal roofing as it is heavy and as you guessed condensate forming; I used corrugated polycarbonate roofing, Suntuff brand, guaranteed for something like 15 years, comes in colours and has some translucency which can be useful.

https://www.bunnings.com.au/suntuf-solar-grey-2-4m-polycarbonate-roofing_p1015729

[bojan]

I also think polycarbonate is very much OK. However, because of Covid restrictions, I can't advise anything else... because I couldn't do anything since March, apart from sliding roof itself, see here (http://www.iceinspace.com.au/forum/showthread.php?t=176799&page=2).

[Anth10]

I can personally vouch for using sarking/sisalation - I’ve had no dramas with condensation to date and is must really for waterproofing. I’m like you Bojan , haven’t had the chance to get to the hardware store to get some earth wool to pack out the rafters in the ROR as yet. I have plans to do this and close it off with some 3mm plyboard to keep it all secured. Although it is starting to gain a bit of weight but hey we don’t want that scorching summer sun to have a chance nor the water droplets now do we.
Good luck Peter- I’m sure it will work out for you.

Anth

[Gadget4x4]

Thanks for the suggestions - will look into both the foil and polycarbonate.
Nice work Bojan - I'm considering a gable roof shed for mine.
With the foil Glen - do you notice any condensation at all?
Cheers Peter

[Gadget4x4]

Earthwool - - I like the idea of a thin layer sandwiched between the tin and the foil - depending on how thin you can get the batts. thanks Anthony.

[Merlin66]

My ROR roof was reclaimed tin roof section from the converted shed.
For the past five years it has been unlined and any condensation has run down in inside surfaces, with some dripping on the equipment.
Earlier this year, I lined the roof with sarking stapled to the wooden joists, so an “air gap” to the tin.
I’m impressed!!
No more drips, I assume any moisture is contained between the roof and the sarking. Works for me and very simple to install.

[Wilso]

Any sort of air gap between the insulation and the iron will work to stop condensation forming underneath.
Foam is also a good insulation, light weight and easy to install.
Plenty of products out there when you start looking. :thumbsup:

[glend]

No condensation Peter, but my roof is polycarbonate (Sun Tuff), it does not sweat like metal. Also there is an air gap between the Polycarbonate and the foil. It does a good job of keeping the temperature inside down in summer. I also used the foil to build a shroud for my mount, it slips over the mount when not in use and is internally heated by a small bulb in winter to prevent pier condensation.

[Gadget4x4]

Thanks - good ideas and options to consider.
Just have to clear the area now for the shed.
At least I have time to weigh up what to do and use.
Cheers Peter

[LostInSp_ce]

+1 for polycarbonate, or anything that's not metal and is lightweight. There's a polycarbonate product specifically for roofing application that has an air gap built into it. I won't post brand names here, but a quick google search and you'll find it. The other benefit to using light materials is the ease that the roof will roll off especially if it's has to be done manually. If it's motorised then weight becomes less of a factor but should still be of consideration. Just my two cents.

[Gadget4x4]

Found a couple of suppliers that do a polycarbonate roofing with an air gap - Thanks for the idea. Cheers Peter