[Greenbuilding] Cellulose

[Laren Corie]

> From: "Robert Waldrop" <bwaldrop at cox.net>

> In working on my project, I found that the 
> Cellulose Insulation Manufacturer's association, 
> http://www.cellulose.org/ , was a good place to 
> ask technical questions.
 
Thanks Bob;

   I called, and Dan and I had a nice long conversation.
Though they have not done any testing on walls that are
thicker than 2x6, 24" OC. they have done a lot of roofs.
He said that for dense pack, on eight or nine foot height,
slumping is a non-issue, regardless of the cavity thickness
or the bay width, which is what I expected.     However,
he did say, for cavity heights around 12ft, that intermed-
-iate support via cardboard, or netting, part way up the
cavity, is advised  He also said, that there used to be an
issue with shrinkage, associated with drying of moisture.
But that, now the insulation is so dry that it no longer is
a concern. He also recommended, as an expert on the
subject, this group's own John Straube, who is now
working with them, on unvented cathedral ceilings,
which is a fairly similar situation to thick walls.

I intend to put clear plastic view holes at the
tops of several of my walls, done in slightly
varied ways, to observe any differences.

To be real safe, here's my recommendation.
An easy piece of insurance, against settling,
slumping, shrinkage, or whatever you wish
to call it, would be to staple a little bit of
fiberglass bat, to the top of the wall cavity.
It will be compressed by the cellulose, but
will then re-expand, to fill any void, should
the cellulose level drop, for any reason.

-Laren Corie-
Climate Responsive Solar Building Design Since 1975
www.LarenCorie.com