[WalksInDarkness]

Hi All,


My HT is in my basement. Along one wall, the wall studs are about 2" away from the foundation, to allow for some PVC drain pipes from the upstairs tub. I want to fill the gap where the wall leads out to the unfinished area of the basement (maybe a couple of inches into the cavity, for sound control purposes only). I am wondering what type of insulation to put there? I would like to use something "porous" to allow humidity to seep out during the wet seasons. But I am guessing it is maybe a bad idea to put fiberglass into direct contact with the foundation? I thought I read once that it is OK to use "Rock Wool" for this type of application, but I am not certain. Any Advice is greatly appreciated.


TIA,

Will

 

[Winkelmann]

In such a small space, I'd fill the gap with Great Stuff (tm).

Do yourself a favor and avoid mineral wool; never before have I itched so much.

 

[WalksInDarkness]



Quote:
Originally Posted by Winkelmann /forum/post/0


In such a small space, I'd fill the gap with Great Stuff (tm).

Do yourself a favor and avoid mineral wool; never before have I itched so much.

The spray foam is one of the options I am considering. I will have to read up on it, and see if it acts as a vapor barrier though (I am trying to avoid a mold situation).

 

[wolverines]



Quote:
Originally Posted by WalksInDarkness /forum/post/0


The spray foam is one of the options I am considering. I will have to read up on it, and see if it acts as a vapor barrier though (I am trying to avoid a mold situation).

Rigid foam is what most people would put in if they were worried about moisture. Not sure what that does for sound though.

 

[Toxarch]



Quote:
Originally Posted by WalksInDarkness /forum/post/0


The spray foam is one of the options I am considering. I will have to read up on it, and see if it acts as a vapor barrier though (I am trying to avoid a mold situation).

The spray in foam is a closed cell foam that should act as a vapor barrier and is bad for sound isolation.

 

[StoneMason]

I used Roxul (mineral wool) for all my exterior walls. Funny though... I found it much less irritating to work with than fiberglass! (not perfect, but better). The Roxul is supposed to be water/mold resistant. Not sure how far you could take that though.


The building inspector (ontario canada), advised that for the exterior walls, it was now common, and good building practice to drape tar paper down the exterior wall against the concrete, framing against that, and the tar paper will keep the insulation from contacting the concrete while at the same time not acting as a vapour barrier.


If you don't have much space to fill, I think the spray foam would be more effective though.