Can Tyvek be used over fiberglass insulation that is falling out from between the roof rafters?
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My parent’s 1975 cape on the Vineyard has an unfinished second floor in which there is one occasionally used bedroom which has been sheet rocked. The rest of the attic is simply exposed fiberglass insulation between the rafters. In some places the insulation is falling out. Can we use Tyvek stapled to the rafters to keep the fiberglass in between the rafters and out of the atmosphere ( exposed fiberglass insulation is an irritant). Technically we want to keep the “attic an unfinished attic”.
If Tyvek is not appropriate can we use the pink resin building paper?
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Replies
Ruth,
The main issue that you need to consider is whether the Tyvek would be a fire hazard. I'm not sure whether DuPont (the manufacturer of Tyvek) or you local code official would approve of your plan. I would certainly check with both of them before proceeding.
Certainly 1/2-inch drywall is safer from a fire perspective than exposed Tyvek.
The pink rosin paper should definitely not be used. It is highly flammable and it is not an air barrier.
You didn't describe whether the rafter bays include a ventilation channel between the top of the insulation and the roof sheathing -- they should -- nor whether the ventilation channels (if they exist) are connected to soffit vents and ridge vents. All of these components -- the soffit vents, the ventilation channel, and the ridge vent -- are required.
Thank you for your quick response.
Not sure about the ventilation channel between the top of the insulation and the roof sheathing. I guess we should find a really good contractor who could scope out the situation before we do anything. The house was built in 1975 and much of the Green technology was not around at the point but I imagine when my father had the house built the they would have known to have ventilation channels.
Thank you -your info and questions are much appreciated.
Best,Ruth
You can easily peek behind the fiberglass to see whether there's a ventilation channel. My guess would be that you won't find one, and you might find some moisture damage resulting from not having one.
Ruth,
I'm at the EEBA conference in Texas right now, and DuPont / Tyvek has a booth on the trade show floor. There were 3 Tyvek reps in the booth when I stopped by, and all three reps agreed that DuPont has no problem with exposed Tyvek in an attic.
Of course, I'm not sure whether you local code official will agree -- but that's the word from DuPont.