[GSBN] Fwd: Humidity within a bale house....

Tue Apr 7 04:39:38 UTC 2009

Strawbale is not the material to use for a high humidity environment.
It is fraught with legal liability.
 Regards,
Bohdan Dorniak

-----Original Message-----
From: GSBN-bounces at greenbuilder.com [mailto:GSBN-bounces at greenbuilder.com]
On Behalf Of ejgeorge at riseup.net
Sent: Tuesday, 7 April 2009 4:34 AM
To: GSBN at greenbuilder.com
Subject: Re: [GSBN] Fwd: Humidity within a bale house....

Ironically, two messages just came through on the NBNE list regarding a
strawbale root cellar and a straw bale walkin cooler with similar humidity
concerns -- I've added them below if anyone wants to comment...

ej

ej George
Certified Sustainable Building Consultant
607-387-3602
ejgeorge at riseup.net

Quoting "Rikki Nitzkin" <rikkinitzkin at earthlink.net>:
>>
>> I have recently gotten an email from a man who wants to build a SB   
>> mushroom farm. He would like to know if it is a problem that the   
>> INTERIOR of the building has a humidity level of 75-90%.
>>
>> I usually prefer to use breathable earth plasters (or lime), but I   
>> am wondering if this would be a good case to apply a WATERPROOF   
>> (cement? latex paint?) plaster to the interior of the building to   
>> avoid excess humidity in the walls.
>>
>> Any thoughts/suggestions?
>>
>> Rikki Jennifer Nitzkin
>> Coordinadora de la Red de Construcción con Balas de Paja 
>> www.casasdepaja.org casasdepaja at yahoo.es 
>> http://casasdepaja.blogspot.com/
>>
>>

Straw Bale Root Cellar...Yea, sounds crazy no?

My client wants to spare the cost of building an underground bunker for a
root cellar. I proposed to incorporate one in the straw bale ?connector?
between the old bale home and the new bale home (this is the Earth Sweet
Home Institute in Dumerston, VT). I generally understand the basic
principles of a root cellar; temp, humidity, air.  
To spare you all the details of the design my main concern is the desired
level of humidity. Two of the four walls of this above ground root cellar
are straw bale and of the two, only one, (the longest), is exposed to the
outside. The other two including the ceiling are conventionally framed with
cellulose or rigid with an AB. What have people used to make the interior
plaster have close to a 0 perm rating? And is this just a crazy idea of
mine?

andy mueller
greenspace colllaborative
www.greenspacecollaborative.com

hmm...

my root cellar is in my basement.  two walls are basement foundation walls,
without damp-proofing or insulation.  the floor has no slab, just gravel and
footer drains.  the other two walls are stud framed; they and the ceiling
are insulated with batts and sheetrocked.  I applied a two-coat epoxy paint
to the rock to make a vapor-impermeable and scrub-able surface.  The
interior humidity should be in the 90% range, optimally; given that relative
atmospheric humidity in the winter is very low, ventilating this air makes
for drier than ideal conditions requiring regular misting and spraying of
the room.  This is where both the diesel wall surface and the drain floor
come in really handy.  Also, things do get very funky in there, so being
able to wash the walls down in h2o2 or other disinfectant is important.

If you wanted to trick out the interior plaster to be waterproof, I suppose
you could just go ahead and apply a similar strong paint to the surface; I
wouldn't bother with anything that couldn't receive a good vigorous
wipe-down, and I'd aim on getting the surface as smooth as practically
possible.

I hope this helps...good luck and keep us posted!

Deva

From: Jacob Deva Racusin <buildnatural at googlemail.com>
Subject: [nbne] straw bale cooler
To: nbne at lists.riseup.net
Date: Monday, April 6, 2009, 1:38 PM

Alright, Andy, I'll see your root cellar and raise you a produce cooler...

I just spoke with a client who runs a farm with his wife, and they want to
build an insulated cooler to store their produce after harvest during the
summer.  They would like to use straw as an ecologically-friendly insulation
material.  They will be putting up the walls within the envelope of an
existing barn; they would remove the siding from the walls where the bales
would be located, build internal-wrap bale walls (barn framing to the
exterior, plaster, and re-side.  Commercial air conditioner will control
interior climate.

Am I missing something in thinking that straw with good plastering interior
and out will be able to handle this situation?  We're looking at 80-90 degF
and high humidity (70-100%?) outside in the summer, and 35-40 degF and much
lower humidity inside.  Of course condensation inside could be an issue, but
the plaster should be able to control that I would think/hope, if the space
is kept ventilated (which it will with powered air conditioner).  Bigger
concern I suppose is condensation in the wall, which seemingly would be most
likely close to the interior, thus a very well-detailed exterior plaster
coat will be key.
This won't have the same pressures of high interior humidity (and associated
decomposition) as the root cellar, although cleaning will still be an issue
to some degree...

Am I being too risky in recommending bales, or does this seem reasonable?
It kinda seems like baling in the southeast, only a bit more extreme...I
appreciate any feedback or resources.  Anyone know of any precedence?

Best,
Deva
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