[masraum]

Originally Posted by Gogar

Is this an exterior wall? If so then you absolutely need to put a plastic vapor barrier on the inside (warm) side of the wall.

If it's an interior wall I don't think you'll have problems doing whatever you want but I don't think you should really try to put plastic on both sides.

As far as sound deadening goes the insulation is nice but air movement is the big thing. A beautifully insulated wall with something as simple as leaky AC box cuts or even a round hole the size of a quarter will negate a big part of the sound deadening.

Interior wall. The old house is like a sieve, but this wall is going to be tight. And the insulation is going to be mineral wool which does cut sound a fair amount. There will be an outlet on both sides, but both outlets will be sealed up (I've got some mass loaded vinyl and some aluminum tape). I know it's not going to be like a studio wall, but hopefully, it'll be better than your average home wall.