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RE: GSBN:Re: Moisture in SBW



A point of clarification
Not all elastomeric coatings are "vapor barriers" but many of the
cheaper and common ones are vapor retarders.
Any coatings or water repellents will reduce the drying outward of
liquid water in the bales, but good quality coatings (high permeance)
and repellents allow vapor diffusion to dry the bales.  Several good
elastomerics are offered by Dow and Sto Corp

John Straube
<a  target="_blank" href="http://www.civil.uwaterloo.ca/beg";>http://www.civil.uwaterloo.ca/beg</a>


-----Original Message-----
From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of Danny &amp;
Fionna Buck
Sent: October 20, 2004 22:51
To: Danny &amp; Fionna Buck; GSBN
Subject: GSBN:Re: Moisture in SBW


Hello again-

It's great to hear the thoughtful response that you have been providing.

A little clarification perhaps on the stucco. The process for the
application of the stucco that I can discern from photographs of
construction is that diamond metal lath was attached to the bales around
the window and door openings and in at least a two foot wide strip up
each corner of the building. The field of the bales was without any
netting or other metal reinforcement.

The first or "scratch coat" of cement stucco was applied with a gun,
embedding it thoroughly into the straw and leaving a fair amount of
stucco-coated straw protruding from the surface. I believe the second or
"brown" coat of cement stucco was then trowelled on forming  a smooth
surface. The final or "color " coat was the elastomeric coat, also
trowelled on. It is similar to latex paint with some aggregate in it for
texture. It stretches as it peels when you pull it off and it provides a
very good vapor barrier, keeping rain and exterior moisture out of the
wall, but not allowing any moisture out of the wall either.

Our idea for repair is to keep the first two coats intact, where the
walls are dry, and just remove and replace the elsatomeric (1/16th of an
inch +/-) with a cementitious color coat. Thus the question of
sandblasting.

I like Derek's idea of blown cellulose, as it dries pretty rapidly. I am
also thinking of refilling the walls with flakes of bales and then tying
stucco netting over them with tie wire that has been wrapped around the
4" concrete columns (on 18" centers running vertical the height of the
wall.) A point of clarification is that there are no blocks in the wall,
rather the bales are used as blocks because they have drilled cores that
are grouted with concrete- as blocks are.

On the insurance issue, the contractor was also the architect, carrying
both licenses, I believe.

Thanks again for the feedback

Danny Buck