Insulate Over Old Insulation

[skeltonj]

I have a 50's ranch lumber framed home w/ about 2" of vermiculite insulation between ceiling joists. Is it OK to put faced roll fiberglass insulation between the joists directly over the old insulation (face down). Don't want to have to remove the old insulation as I have heard there is a cancer causing concern if you disturb vermiculite. Thx.

[pushkins]

Your right there is a concern with carcinogens and vermiculite and without the proper face masks you'd be in the middle of a bad place to be.
I can see no problems with you using faced insulation with the face side down.
Make sure you still wear a face mask doing this job.
Best thing is it will help reduce the airborne particles from the vermiculite.

[mrcaptainbob]

Insulation...

Maybe unfaced insulation would be better? Doesn't sound like a good way to go sealing that first insualtion between the ceiling and the new insulation face as it could be an issue for condensation.

[kactuskid]

Captainbob is right on. Absolutely do not install insulation that is faced. This vapor barrier will definatly trap moistue and you'll end up with big problems. Just leave the vermiculite alone and install the unfaced batts ontop inside each cavity. Here's a link that'll explain :

http://www.owenscorning.com/around/insulation/faq_attic.asp

And here's another one to help you out with additional info:

http://www.ornl.gov/sci/roofs+walls/insulation/ins_12.html

Also, where a respirator that protects against asbestos fibers when installing your new insulation up there in the attic. Not all vermiculite contains asbestos but most does and there's no way of knowing what type you have unless you take a sample to a local lab and get it checked out. It's only dangerous when it becomes airborne so try not to kick it up too much while working up there. Below are a few more websites to give you lots more info about it.

http://www.inspectmichigan.com/watsonsj/May00WJ.htm

http://www.radonpro.com/Vermiculite.htm

[pushkins]

I appologize I just re read what I wrote and see an error. I added a "no" in there about the faced insulation.

I meant to write " I see problems with you using faced insulation with the face side down".
This as pointed out by previous posters is the "correct" advice.

See what I get for thinking about three things while typing about one !!

Sorry if I mislead you !