Slash trhe vaporbarrier?


Old 04-09-02, 02:20 PM
Visiting Guest
Posts: n/a
Slash trhe vaporbarrier?

Hi, we recently bought a Cape Cod style story and a half, and I added R-19 fiberglass strips to the two inches of apparently rock wool that was already there - over the first floor. The knee walls, cathedral like ceiling part and attic over the second floor are a different story, complicated by my lack of access to the attic over the second floor. Now, I did the R-19 insulating over a few weekends, and when I started, I thought,"Cool, the existing stuff is in some sort of bag, this makes I dusty annoying job easier" (and it did). Now I am thinking that either a) the existing insulation was installed upside down, that is, with the vapor barrier facing up or b) the insulation was wrapped in a sheath. I will have to totally rip up one part of the existing stuff to see whether a) is the case. Assuming b) is the case (the sheath), then I figure my options are to 1) slash the top of the vapor barrier on the existing stuff 2) ignore the issue (because it doesn't matter much or 3) do something else (that someone here might suggest). Any comments? I saw the slashing part in a Popular Mechanics insulation book.
And does anyone know a cheap source of R7 batts or blankets. The little utility insulation packs from Owens Corning of something like four feet of R7 2 inch insulation are perfect to add to the knee walls in the attic, but at $4 each (and I might need a hundred or so four foot lengths), they will add up right quick. Does anyone sell a roll of R7?
Sponsored Links
Old 04-16-02, 03:23 PM
Visiting Guest
Posts: n/a
try a drywall supply house for the r-7 batts in quantity... We sell it here in Michigan for about 17 cents a square foot.
not sure what to reccommend in regards to your existing insulation. If it was me I wouldnt worry about the vapor barrier.

Good Luck

Old 04-17-02, 02:10 PM
Visiting Guest
Posts: n/a
Good tip

Thanks for the suggestion, I was drifting in that direction, though the home centers are more convenient. I may simply grit my teeth, buy some R-19 and snip jagged batts of R-7. It would be cost effective, and keep me out of trouble for a while.

I found an acceptable answer to the vapor barrier question in another post as I looked around. I guess with the age of the insulation, it was commonly kraft wrapped back then. but it crumbles if I poke it, so there is no tar backing on the cold side. I am thinking I will leave it alone, just hope there is tar on the warm side.
Thanks again for the suggestion.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes