Re: [GBlist] vapor barrier

["Christopher S. Weller" <chris_penny@hotmail.com>]

 I think if you sandwich the insulation between layers of vapor barrier
 material, you might be forming a cloud chamber in the insulation board.
 There will be no where for moisture or vapor to escape out of the
insulation
 if any should get into it.  Maybe I am wrong and others will chime in to
 correct me but I would not install a vapor barrier underneath the rigid
 insulation if it is directly beneath the vapor barrier for your roofing.

You are correct
Depending on what kind of roof /attic/ceilings you have there are different
types of
methods to use but how green they are I have no idea that is why I joined
this list
I build/remodeled house as a foreman for 10(ten) years

if you are using a cathedral style ceiling they make a piece of plastic that
can be bought in the building material section of places like Home Depot and
Lowes that keep the air flowing from bottom to top of your roof so that the
moisture does not build up inside the confined space and cause rot/mildew
and a few other
nasties that can and will happen to a totally enclosed space



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