Cob codes & Locations

[Shannon C. Dealy]

On Thu, 13 Aug 1998, douglas scheffer wrote:

> I've been seeing several posts from people wanting to build cob here in the
> Northwest. This surprises me because every time I have a discussion with a
> contractor, they tell me it's great in the Southwest but "that stuff will
> just melt like butter up here in all this rain, not to mention the mold."

There are numerous cob structures in the Northwest, probably due to the
fact that it is where Cob Cottage Company is located (Cottage Grove,
Oregon).  As far as cob being great in the Southwest but "melting like
butter" in the Northwest, it simply isn't true.  This statement may be
due in part to confusion between traditional adobe and cob which while
related have significantly different mixes and characteristics.  Cob is in
fact a traditional building material in Wales, England where there are
thousands of 100+ year old cob structures still in use.  Wales has a
climate similar to the Northwest, but with much more wind driven rainfall.
The reality is that with proper design of your structure, even unpainted
exterior cob walls should last for decades without significant damage, and
if you don't take these same precautions for conventional building design,
a typical wood frame structure will deteriorate and fail even faster than
cob would.  The only case that I am aware of in which a wood frame
structure is likely to be superior to cob when exposed to the elements is
in the case of a flood where you have standing water in direct contact
with the building structure.  A wood frame building will dry out in time
without significant damage to the structure, where the cob building is
likely to collapse during the flood due to softening of the cob from
absorbtion of water.

NOTE: For those of you who are concerned about your cob getting soft due 
to wind driven rain on the side of your building, don't worry, most rain 
that hits even unprotected walls will simply run off, and it takes an
enormous amount of absorbed water to actually soften cob.

[SNIP]
> If the Northwest is not a great place to do this, is there a list of
> states, counties, towns or provinces that have approved cob building. I am
> not limiting my self just to the Northwest, If it's easier to build
> elsewhere I'll consider it.
[SNIP]

As far as finding a place where it will be easier to build, there are
a few counties scattered throughout the U.S. which have no building code
requirements, so they will be easier to build in, otherwise, it depends on
your local building department as to how easy it will be.  In the
majority of cases, where ever you go, they will have no experience with
cob, nearly all cob structures in the US were either built without a
permit (either illegally or because none was required), or on an
alternative permit such as for an agricultural building.  The county
I currently live in (Linn County, Oregon) has a building official who is
very friendly to cob so it should be comparatively easy to get a permit
here (unfortunately the land I will be building on isn't in this county).
On the other hand, an adjoining county (where my land is located), has a
reputation for being hostile to any kind of building (conventional or
alternative), and take the attitude that if it isn't in the code, they
won't even look at it if it doesn't have an architectural engineer's stamp
on it.

Shannon C. Dealy
dealy at deatech.com