I removed all of the lath and plaster in our upstaris bedroom. I insulated the walls and ceiling with faced (vapor barrier built in)insulation. The vapor barrier is facing towards the heated side of the house. I would like to know if I should install 4 or 6 mill poly in addition to this to make sure any tears in the paper or small gaps around outlets, studs, joists, and the like are permantely sealed. I wanted to follow this up with applying insulation tape over the seams in the poly.
I am not attempting to apply a second vapor barrier on the outside of the insulation (vapor barrier, insulation, vapor barrier), rather, I was going to apply the poly directly over the existing vapor barrier.
What do you think? Please help!! I am getting many different answers.