Insulation/Vapor Barrier

Should I install a vapor barrier behind an acrylic surround?

2 walls interior and 1 is exterior.

On the exterior wall is the faced insulation enough of a vapor barrier?

Also...
I currently have insulation between the 1st and 2nd floor of my house (Cape Cod). Both are used and heated. Should I replace or remove this when I replace ceiling in the 1st floor bathroom. 2nd bathroom is directly above.

Thanks

OBDECKS said:

Should I install a vapor barrier behind an acrylic surround?

2 walls interior and 1 is exterior.

On the exterior wall is the faced insulation enough of a vapor barrier?

Also...
I currently have insulation between the 1st and 2nd floor of my house (Cape Cod). Both are used and heated. Should I replace or remove this when I replace ceiling in the 1st floor bathroom. 2nd bathroom is directly above.

Thanks

Click to expand...

Technically the kraft paper used for the insulation is enough, but I always use 4mil poly on exterior walls. You don't, however, want two layers of vapor barrier in any wall. An easy remedy for this is to cut slits in the kraft at 2' intervals, then cover with poly.

Not a good idea for vapor barrier in interior walls.

The insulation between floors helps greatly to reduce noise transmission between floors. Leave it there. The builder took pride in his work obviously, since most leave this out.