insulation of open joist bay in bathroom
I want to insulate the open joist bay in my bathroom that I’m renovating, before putting subfloor down in this area.
there’s a lot of uneven spaces in this area due to blocking (some that i’ve added and some previous).
i read that using fiberglass insulation wrapped in a plastic bag can work. I did that with one area here. i’ve attached a pic or two, including a pic where this is discussed on another site.
My questions are:
1. is there an issue with flammability with this tactic? nothing was mentioned in the sites discussing this.
2. since the plastic bag completely wraps the insulation, creating a vapor barrier, is there any issue with moisture forming on one side of it?