OSB Expansion Gaps For Warm Roofs

[emjay1711]

I'm doing a build, with a warm roof, in the garden and wondered about OSB and expansion gaps.

I've read that each sheet needs an expansion gap between it and the next one. However, I've also read that sheets can be butted up to each other with no gap but you then have to leave a gap around the whole perimeter.

I don't know what's correct here.

Leaving a gap between each board doesn't make sense - especially for the OSB top deck that is laid over the PIR. It would also make the bonding of the rubber roof tricky and it would look odd as the gaps would be visible (and with water pooling in the "gaps").

Comments and thoughts appreciated.

 

[noseall]

I'm doing a build, with a warm roof, in the garden and wondered about OSB and expansion gaps.

I've read that each sheet needs an expansion gap between it and the next one. However, I've also read that sheets can be butted up to each other with no gap but you then have to leave a gap around the whole perimeter.

I don't know what's correct here.

Leaving a gap between each board doesn't make sense - especially for the OSB top deck that is laid over the PIR. It would also make the bonding of the rubber roof tricky and it would look odd as the gaps would be visible (and with water pooling in the "gaps").

Comments and thoughts appreciated.

I've never bothered with ex'-gaps.

 

[catlad]

No gaps in stand alone building, if you are building up to something inflexable like masonry then you would be wise to leave a 10mm gap