vapor barrier to support blown in cellulose in the attic

This is a homeowner forum question, not a finished news story, so there isn't a definitive answer to report. A homeowner planning an attic insulation job asked for advice on separating their living space from a vented attic before adding R-60 blown-in cellulose insulation. R-60 is a thick, dense layer, and the poster wondered whether 6-mil plastic sheeting (poly) stapled under the attic joists, with drywall installed over it, would hold up the weight of all that insulation, or whether another product would work better as both a vapor barrier (a layer that limits moisture from passing through the ceiling into the attic) and a support surface for the cellulose until the drywall goes up.

At the time this was posted, no one had answered yet, so there is no verified recommendation to pass along. For anyone doing a similar attic upgrade, the underlying question is a real one: dense-pack or deep blown-in insulation needs something sturdy enough to hold its weight before the finished ceiling goes on, and the choice of material can affect both how well moisture is controlled and how safely the insulation stays put. If you are planning deep attic insulation in your own home, it is worth asking your contractor what they use to support the insulation load and how they handle moisture control at the ceiling line, since practices vary by climate and house design.