[Cob] your cob home

[Shannon C. Dealy]

On Sat, 13 Mar 2004, Pack McKibben wrote:

> Shannon,
> What kind of foundation did you build?

Stone mortared with cob on top of a rubble trench.

> How high is it off the ground?

Because it lacks any low level bond (cement), I decided to go with a very
low foundation, much of it is essentially one large rock tall (8 to 12
inches).  This effectively embeds much of the rock the wall is sitting on
directly into the bottom of the cob, making it much more stable in the
event of an earthquake.  We're not a high risk area, though I think the
risk here was recently upgraded, but between this, the round shape,
small diameter, and all the wood between levels and in the roof, I'm quite
certain it is a safer structure than most of what has been built in this
area.

The lack of foundation height shouldn't be a major water issue since
it's on a rubble trench, there is a reasonable amount of slope to the
land, and the wide roof overhang keeps even the bottom of the walls dry
most of the time.

> How long did it take you to build the cob section by yourself?

About six months, but the limiting factor wasn't me, but drying time (I
could cut it by half based on what I learned doing this), since I started
building in November and moved in in May -- winter cobbing in a wet
climate, yes I am nuts :-)

> How much head room is on the first floor?

Depends on where you (attempt :-) to stand.  Sitting at my desk, I can
reach up with my elbow and touch the ceiling (actually shelves screwed
into the bottom of the floor joists).  Standing next to the
ladder, any basketball player in the NBA would be comfortable, though
their view would be of the second level :-)  Standing beside my desk and
chair, my hair touches the ceiling (I'm 5'10"), this was a mistake, it was
supposed to be about three inches higher, but shrinkage and settling were
much greater than I had planned on.  This was a result of mistakes in my
skid loader cob mixing technique that resulted in a much higher clay
content than it should have had -- see the archives for an earlier
discussion of my skid loader problem.

> Is your loft half as big as the first floor? or less?

The loft is definitely much shorter than the lower level, where the roof
is at it's high end, there is enough head room for me to sit up in bed
without problem.  Following the roof slope, height goes from about 3'8"
feet max down to probably about 2'6", though there is an area of the loft
that drops down where I can stand slightly bent over (perhaps 5-1/2
feet max).

> Is there electricity in the building?

Solar panels, battery bank, power inverter and backup generator.

> Do you have an outside bath/shower, toilet?

Sawdust toilet and shower made using a watering trough and garden hose,
both in a small (8'x8') green house.

> Do you have a kitchen?

Was using a propane stove in the house for a while, but that kicks out
alot of moisture for a very small tightly enclosed space in winter, and I
really don't have much time for cooking these days, so I've switched to a
small microwave.  I also have a small 1.7 cu ft. refrigerator.  It's not
particularly efficient, but it still uses less power than anything else
I've seen, the sunfrosts and such are much more efficient, but that is
relative to their size, in terms of actual total power consumption, mine
uses less, and for $57 new, the price is hard to beat.  I plan on seeing
if I can modify it to improve it's efficiency later this year (extra
insulation, possibly coupling the heat exchanger to the cob walls, etc.),
and if I wreck it, well, it was only $57 :-)

> You said it was 70 sq. ft. inside.  So you're living in a less than 10
> foot diameter building?

Yes, 12' exterior diameter, about 9'8" interior diameter (more or less).

> I keep looking at my 10 foot diameter tool shed (that I'm now working
> on) and want to move into it. Should I?

Your call, any reason you shouldn't?  According to my estimates, my house
has roughly the same cubic footage as a 20 foot motorhome, and lots of
people live in those, and they even have the bathroom inside.  The biggest
issue I have had is moisture in winter (exhaled, propane stove, etc.).
Keeping the building closed up traps the moisture causing condensation and
even some mold, opening the building of course makes it colder, but
eliminates the moisture problem.  Since I went through this winter
essentially without heat, it was an issue.  Now that I no longer need
it for this year, I can finish the heating system :-)  Big lesson here,
when living in something this small, finish it if at all possible before
you move in!  There were things I had to do before I could complete the
heating system, which I found that I couldn't do in winter while living in
the building.

> Do you have any pictures of your home?

Yes, though they won't be posted until I complete a major upgrade on the
web server.  I will post a message to the list when it gets done . . .
(Mark, I know what you are thinking -- sometime in the next five or ten
years :-)


Shannon C. Dealy      |               DeaTech Research Inc.
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