[bigcat47]

I tore down old drywall in my utility room and want to add roll insulation between the wall and ceiling studs. Then a drywaller guy will put up new drywall. Previously there was only blown insulation between the ceiling studs, nothing in the walls. Of the roll insulation, one kind has a paper backing, or "face" and the other does not. I've heard varying opinions from two different store clerks on which one to use. One clerk was concerned about trapping too much moisture and didn't really recommend paper-backed roll insulation at all while the other clerk didn't say much about that possibility. Two of the walls separate the room from the outside while the other two walls separate interior space. I appreciate your comments/opinions.

[ebaines]

Insulation between interior wall can be unfaced. The insulation used in exterior wall should be faced one side only, and you place it so that he face is towards the "warm side" - which in most applications is toward the inside or living area. The reason for this is that the warm inside air will generally be higher humidity than the cold outside air, and if the humidity was allowed to migrate through the insulation from the warm side to the cold it could condense out and form moisture that would build up in the insulation and on the inside of the exterior wall. But by using the faced insultaion you prevent air movement from inside the room through the insulation, and hence condensation doesn't occur.

[joypulv]

Some people put unfaced in walls that need the vapor barrier and then cover it all with plastic. But putting up faced insulation is easier to handle.
Sometimes it's a matter of what's on sale. I just got a deal on unfaced at Home Depot for a closeout size, unfaced, for about 60% off regular price.