[Cob] strawbale

[Barbara Roemer and Glenn Miller]

Hey, Global Circle Net,

Your post really grabbed my attention and raised my hackles.  I'm a staunch
cob supporter, and particularly interested in code being developed to
support its use (even went so far as to pay Otherfish, John Fordice, for a
couple of hours of his extremely well-informed advice to advance the cause
in my county).  I am also a long-time advocate for bale building, having
built the first rice-straw building in the country with my California 5th
graders about 12 years ago....  We are partners with another couple in a
light straw/clay mixer which my son built, and which we have used to build a
straw/clay infill building.  My experience with natural building materials
spans many approaches.


Your uninformed post is the sort of misinformation that has made the general
public skeptical about bale building.  Happily, it hasn't resonated with
those who do even a smattering of research, the 3,000 or so of them in this
country and probably an equal number around the globe who have built, often
permitted, gorgeous simple or complex straw bale buildings as homes,
workshops, studios, meditation spaces, clinics, office buildings, and
wineries.  A fad?  Your head must have been under the covers for a loooong
time.  Were straw building, whether it's in the form of bales, in light
straw clay, or in cob, so wildly impractical, it's unlikely there would be
ANY permitted buildings.  There are even jurisdictions in this country which
are now offering incentives by way of green-building credit to bale
builders.  It's not only legit., it's becoming most desirable!

NOW:::

Every tight building must have roof insulation, even cob structures.  What
does "regular" insulation mean?  Is that fiberglass, or fiberglass without
formaldehyde, or blown in cellulose, or recycled jeans cotton batts, or foam
board?  How about bagged or blown in rice hulls?  A perfect use for a waste
product whose current use is primarily as a soil amendment, but whose future
includes being compressed with natural resins as a dry wall replacement.
Critters?  Ever looked as your fiberglass or cotton or even foam insulation
in the walls for evidence of nesting critters?  In our area, everything
loves all insulation except properly plastered bales.  Plaster of some sort?
It's exactly the same plaster you'd use on your cob building: earth, chopped
straw, perhaps lime, perhaps magnesium chloride, perhaps seaweed.  Could it
be stucco or gypsum?  Yes, but that's much less likely.  Those baleheads
have the same concerns we cobbers do, including a predilection for natural
materials with low embodied energy.  Yes, plaster must be properly
maintained, and depending on your climate and the overhang protection for
the walls, that might mean a lime wash as often as every 5-10 years.
Interior plaster isn't any more or less fragile on bales than on cob, and
will need to be recoated or repainted no more often than the wear and tear
of its occupants dictate.

Moisture is no more likely to develop in a properly detailed bale home than
it is in a cob home or a conventionally stick-framed home or a Rastra block
home.  It's all in a proper foundation and roof, exactly the same
constraints no matter what the building system.  And any building can give
its occupants sick building syndrome if ventilation is not handled properly.
I've seen far more mold on cob walls than on bale walls, but it is not
difficult to avoid mold in either.

The cost of a non-load bearing straw building if you hire a contractor and
have the work done is comparable to that of stick framing and depends almost
entirely on the foundation, fixturing, flooring, wall finishing, windows and
roofing - all the considerations that are present in costing out any
building.  Wall systems are a small percentage of the total in any building
system.  Just for comparison's sake, straw bale building entails no further
insulation in the walls, and its plaster provides significant thermal mass
on the insulated inside, whilst cob building needs no further thermal mass,
but provides little insulation and the mass is not insulated.  Straw
building is just as accessible as cob building, the detailing is simple, the
code provides for it, even in seismically active zones like the Bay Area,
and it's quick to erect, so for many people, it's the way to go.  It's far
better insulated than a stick framed house with stud cavity insulation: to
get comparable insulation with stick framing, you'd have to do a wrap of
foam, hardly sustainable.  Cob is more easily sculpted, usually found on
site, provides great mass, and is easy but slow for the owner builder to
work on herself.  Cob building for a dwelling is currently permitted (as far
as I know) in only one county in the country, and the obstacles to cob
building in seismic zones are formidable.  When significant investment in
engineering and testing has been made, cob building may be feasible in
seismic zones.  For me, the best home will be a hybrid, including
straw/clay, bales, and cob, each where it's most appropriate. It will be
low-cost, pay-as-we-go, with us doing most of the work because it's ALL user
friendly.  It won't outgas toxics, will contain very few materials that
aren't locally available, and will last our children's grandchildren's
lifetimes, at some point in the future sinking gracefully into the earth
from which it came.

We in the natural building world have a lot to learn from each other, and we
all benefit from examining the claims and strengths of each type of
building, incorporating what is sustainable, local, practical, and
beautiful.

PJ, contact me off-list if you want to discuss bales further.  There are
several farmers in northern California who have adapted baling machines to
provide building bales of very tight, dense, uniform configuration.  Rice
straw with its high silica content is unpalatable to insects, isn't used as
fodder, and is essentially a renewable waste byproduct of rice growing.
Please don't use baled weeds or hay: we know a lot more about appropriate,
sustainable materials than we did when the buildings in the Sand Hills of
Nebraska went up in the 1800's. Those of you who are further interested
might even hang out on the SB-r-Us list at Yahoo where you'll find very open
folks.

Barbara in the Sierra Foothills.