RE: [GBlist] benign wall insulation

["Ralph Bicknese" <ralph.bicknese@christnerinc.com>]

Ruebin:

I have not used cotton insulation but it seems that with an absorbant
material like cotton or cellulose a properly detailed and properly installed
vapor barrierwould be even more important than with a less absorbant one.

With virtually every insulation the dewpoint temperature can be reached
within the insulation.  This would be especially critical with an absorbant
insulation such as cotton.  It is even important in a non-absorbant
insulation such as fiberglass batt insulation.  In the case of fiberglass,
the fiberglass will not rot from being damp but if it contained moisture
could lead to structural, and/or siding damage, could lead to mold and
mildew problems, and could create a nice environment for moisture loving
insects.  All this is also true for cotton and cellulose except that these
will absorb mosture and can themselves rot.

In a "heating climate" a vapor barrier on the warm side (indoor side) is
highly desireable to reduce the flow of moisture into the insulation to help
keep the moisture from condensing when it reaches the dew point temperature.
In a primarily cooling climate, such as in Florida, a moisture barrier on
the inside can be detructive, and is debateable on the outside.  I would
really question the practice of using cotton insulation in a high humidity
warm climate.  Vapor protection would be extremely critical there.

Cheers,
Ralph Bicknese

-----Original Message-----
From: Reuben Deumling [mailto:deumling@socrates.Berkeley.EDU]
Sent: Wednesday, May 30, 2001 2:54 PM
To: Ray Zorz; greenbuilding@crest.org
Subject: RE: [GBlist] benign wall insulation


I've succeeded in obtaining a sufficient quantity of cotton
insulation for this project, and I am wondering what (if any) vapor
barrier might be appropriate on the inside of this insulation.  This
stuff comes in batts, but not with any backing.  Does anyone on this
list have experience with installing cotton insulation?  Thanks for
any insights.

Reuben Deumling

At 12:51 PM -0700 5/2/2001, Ray Zorz wrote:
>For cotton:  <http://www.bondedlogic.com/insula.htm>
>
>-----Original Message-----
>From: deumling@socrates.Berkeley.EDU
>[<mailto:deumling@socrates.Berkeley.EDU>mailto:deumling@socrates.Berkeley.E
DU]
>Sent: Wednesday, May 02, 2001 12:46 PM
>To: greenbuilding@crest.org
>Cc: terrain3@home.com; JSties@McDonough.com; john.daglish@vnumail.com;
>cree@dowco.com; sigikoko@earthlink.net
>Subject: [GBlist] benign wall insulation
>
>
>Perusing several recent (late 2000) discussions of insulation products on
>this list I count the following material (categories) mentioned if not
>actually recommended:
>sheep's wool
>cotton
>cellulose
>mineral wool
>fiberglass
>
>The project I am planning involves removing the interior siding from a
>35-year old never-insulated house (2x4studs) on the Oregon coast for
>purposes of adding insulation.  I'd prefer to install the material myself,
>so I suspect blown in cellulose may not be such a great choice-true?  Also
>I'd appreciate if anyone knows of and could pass along contact info for a
>US distributor of sheep's wool insulation.  Should I expect substantial
>shipping charges for some of these less than common products if they come
>from halfway across the country? Also I am curious as to vapor barrier
>materials or thoughts folks might have.  It is a pretty damp climate much
>of the year... Other thoughts on materials pro and con are also most
>welcome.  The wall area to be insulated is approximately 800 square feet.
>
>Thanks
>
>Reuben Deumling


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This greenbuilding dialogue is sponsored by REPP/CREST, creator of
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______________________________________________________________________


______________________________________________________________________
This greenbuilding dialogue is sponsored by REPP/CREST, creator of
Solstice http://www.crest.org, and BuildingGreen, Inc., publisher of
Environmental Building News and GreenSpec http://www.BuildingGreen.com
______________________________________________________________________