[Cob] Coblist Digest, Vol 10, Issue 24

[Monica Proulx]

Sorry for sounding like a broken record, but....

For an interesting introduction to earthquake "resistant" building method
using earth (not strictly "cob" as in its reinforced monolithic building,
more like wattle and daub), go here:

http://practicalaction.org/earthquake_resistant_housing

This web page is just a brief introduction, there is much more.

(By the way from reading on the topic, I believe there's no such thing as
100% guaranteed earthquake "proof" housing.)

Search terms (doing an image search is very fruitful also) - quincha,
Practical Action, Peru, Payson Sheets, earthquake resistant homes,
monolithic adobe (this is a term very similar to "cob", lots of folks south
of us use that name.  There is quite a bit out there on the topic.  The
quincha method uses vertical reinforcement by bamboo with horizontal woven
elements (the panels are tied into vertical columns, especially at
corners). This allows more flexibility in a quake, damage may only be to
the adobe on the wattle and daub structure. The vertical columns hold up
the roof, and if the adobe gets damaged, it falls off and can be repaired.
This is an ancient method (goes back to pre columbian Mayan villages almost
3,000 years ago).  Not sure if my memory serves me correctly on this, but
it makes sense - to build in a way such that if your building gets damaged
in a severe quake, it doesn't kill you.

There are excellent examples preserved in volcanic ash (the method doesn't
hold up as well to volcanoes as it did to earthquakes) in El Salvador at
Joya de Ceren.  Several thousand houses in the last decade or two have been
built in Peru (owner builder method), using concrete floors and foundations
(unfortunately, building codes?), but there are and have been quincha type
buildings being done without concrete.  These newer houses have held up
well to subsequent Peruvian quakes.

The fact that indigenous people are still building today in a more
primitive quincha style (than Practical Action teaches), shows that it
works.  It doesn't get much better than 3,000 years of field testing. The
Peruvian method is an updated version.   For purists that don't want wood
in their building walls, this method is a no-go of course.  Bottom line,
there's more than one way to skin a cat (sorry, all you cat lovers).