sarking alternatives

[JohnD]

where I live in the south, sarking board is not usual. However it is a coastal area subject to strong winds, and I was considering having WBP ply sarking added if and when it needs reroofing.

My commercial premises (exposed roof) have kingspan laid on the rafters of the storeroom, with synthetic slate on top. I can see this improves the thermal efficiency. I can see it would also mean the gutters would need to be stepped out.

Would the weight of ply be a problem? The house has calculated trussed rafters.

What else should I be considering?

 

[catlad]

I would have thought the added strength of the ply would compensate for the weight of the ply, also you would need to counter baton so there would be a small height difference which should not be an issue if you are detached.