Exposed Intello Plus Membrane in Attic
I know this is ultimately a matter for my local code official to answer, but I’d like to know if there’s any clear guidance on this before approaching them:
Is it acceptable for Intello Plus covering dense-packed cellulose to be left exposed in (a) a nearly-inaccessible attic space, and (b) a behind-kneewall space used for storage and mechanical equipment?
The specifications of Intello seem to be conflicting. According to the spec sheet, surface burning per ASTM E48 is class A, 0 flame spread and 35 smoke developed index, which would meet the (Ohio) residential code requirements for both “wall and ceiling finishes” and “insulating materials” (though it’s not exactly either). However, the same spec sheet indicates fire class E by a European standard, which google tells me is the second worst and is described as “high contribution to fire” — which makes it sound much worse.
So, which is it — perfectly fine to leave exposed, or gonna burn quickly and should be covered with drywall (which would be a real pain)?
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