Hello all. This is my first post although I’ve read fine homebuilding for some time now. I’ve finished rebuilding my first home which was a straight forward stick framed home originally built in the 80’s. I’m working on my new home now which is a cape built in the late 40’s. The house was built with 2×4 studs, 16″ on center, sheathed with black Celotex fiber board of some type, then clad with a brick veneer. The home originally had plaster board on the interior and absolutely no insulation what so ever. I am about to insulate prior to installing 1/2″ Sheetrock. I purchased Rolux safe and sound insulation which is stone wool. The packaging states the insulation is 3″ in depth. My question is if I install this insulation and the void in the wall is 3.5″ deep should I leave the space toward the outside so any moisture from behind the masonry can evaporate? Or should I leave the gap toward the conditioned space? Also, they’re unfaced batts. There are a ton of opinions on both sides about vapor barriers, but do you think one should be installed and if so, what kind? My home is located on Long Island NY which has all seasons and the moisture to go with all of them. Thank you in advance for any advice.
Replies
safe&sound is not thermal insulation
http://www.roxul.com/residential/create+a+quiet+home/which+safe+n+sound
Roxul safe/sound is for interior wall noise reduction and fire resistance. You need the Comfortbatt. http://www.roxul.com/products/residential/products/roxul+comfortbatt
I used both extensively in a remodel and it's great.
Thanks for the info. So much for the guys at the store knowing what they're talking about, guess I'll have to return it for the other. Did you use a vapor barrier?
no vb
dc area, and I looked long and hard at that question, and in the end I did not use a vapor barrier because the house had two layers of 30# and some kind of foil wrap over that on the outside of 2x6 studs (then 2 1/2" layers of plywood sheathing), and I didn't want to create a double barrier. On the inside, there was new drywall,air sealing with caulk and foam, primer and two coats of Ben Moore, though, so there was lots of opportunity to minimize moisture transfer anyway.
More important than a vapor barrier, and even insulation, is air sealing. Especially in a coastal area, keeping the wind from blowing through makes a major difference in comfort, in addition to keeping out weather and bugs. I'm a big fan of house wrap, but where that is impractical do whatever you can. You may think that no air gets through the brick and Celotex, but that is not the case, especially around windows and other penetrations.
Thank you to everyone for the advice.
FWIW, if it's unfaced insulation it makes no difference whether you set it on the inside of the cavity or the outside.