Minimum Plywood Thickness As An Air Barrier
A number of articles and blogs have been written on using OSB ( https://www.greenbuildingadvisor.com/article/flatrock-passive-insulation-and-an-air-barrier ), plywood/zip ( https://www.greenbuildingadvisor.com/article/study-finds-osb-sheathing-not-a-reliable-air-barrier ), and smart vapor barriers ( https://www.greenbuildingadvisor.com/article/urban-rustic-air-sealing-the-attic-floor ). They all illustrate various methods of air sealing a building using those materials along with their pro’s and con’s.
My question is: what is the minimum thickness of plywood one could use for air sealing (ie. not structural, but for air sealing purposes only).
It seems to be *generally* accepted that 1/2″ or greater is required for OSB. Zip is…….Zip and any of the smart vapor barriers are whatever they are. But I do not think I ever recall an article detailing the minimum thickness of plywood and that they all used at least 1/2″. Has anyone tried 3/8″ or even 1/4″?
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