# Breather membrane in roof?



## That would work (17 Aug 2019)

Hi, workshop build progressing well (thanks Mike). I am doing the roof with Onduline. As I will have some breather membrane left over was wondering if there is any point using it above the insulation in the roof?
Thank you
Tim


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## MikeG. (17 Aug 2019)

Yes, so long as the build-up is right. Describe your roof, from inside to out.


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## That would work (17 Aug 2019)

It will have an osb ceiling or if another board I'll put a vapour barrier above. 6x2 joists (it's an 8' span), 25mm purlins 150 rock wool bats. Onduline, insect mesh. Flashing down the ends. The pitch is just over 5 degrees. .. I know this is the bare minimum but I'm going to increase the overlap quite a bit.


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## That would work (17 Aug 2019)

....and 600 joist spacing


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## MikeG. (17 Aug 2019)

OK, then it actually _should_ have a membrane over the joists.


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## That would work (17 Aug 2019)

Thanks Mike, very helpful 
Tim


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