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Expansion gaps in roof sheathing

MHunt11 | Posted in General Questions on

Do you need a 1/8th expansion gap in your roof sheathing when you have 16 o.c. Framing? This is on an unvented 1:12 slope roof with metal panels. Closed cell spray foam will go on inside of roof sheathing if that matters.

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  1. Expert Member


    The gap is not dependent of the spacing of the framing. All that affects is whether you need mid-span supports (like H-clips) or not. Yes you need to leave an expansion gap of 1/8". Many large sheet goods suppliers, like Weyerhaeuser, size their sheets accordingly.

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