Sayulita Tierra Firma Earth block newsletter Vol 1, #2

Sayulita Tierra Firma: Build It With Dirt!
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Your Local Compressed Stabilized Earth Block (CSEB) Newsletter: Volume 1, Number 2, March 2011
Building with Earth: World Heritage Sites & Usage Today
Building with Earth: Local Scene Highlights
Earthen architecture is one of the most original and powerful
expressions of our human ability to create and build environment with
nearby available resources. It includes a great variety of building
types and groups, ranging from mosques, palaces and granaries to
historic city centers,
cultural landscapes,
and archaeological
sites. Its cultural
importance throughout
the world is evident and
has led to its
consideration as a
common heritage of
humankind, and
therefore deserving
protection and
conservation by the
international
community. In 2007, 106 out of 660 cultural properties inscribed on
the World Heritage List incorporate earthen structures. Thanks to the
materials’ availability and economic quality, it bears great potential to
contribute to poverty alleviation and sustainable development.
Source: The UNESCO World Heritage Earthen Architecture
Programme (WHEAP)
Machine and Blockyard Site Preparation: Last week we had a
great turn out for the work parties at the Sayulita Tierra Firma Earth
Blocks production site. Dan Gair, Fred Geisler, Laurie Keith, Mark
Joyous, Mike Cavanagh, Richard Presley, Rick Kahn, and Wes
Stobbe all came out to prepare the machines, clear the site, to learn
what was going on and support the activities. We now have an area
that has been 90% cleared of undergrowth, and machines that are
99.9% ready to produce blocks (just a few little fasteners and fittings
remain to be sourced).
Earth for blocks arriving soon: Antonio Jiménez stopped by the
Tierra Firma site on Monday (21-March) to view the block presses
and discuss the type of earth we need. Antonio says that the presses
are very similar in concept to ones that he used a long time ago for
the production of Spanish tiles, which are also made from an unfired
mix of cement and sand that has been compressed. Antonio
explained to Richard the availability of different colored clays, and
also that the cost of soil was directly related to transportation
distance. Antonio is bringing four 5-gallon buckets of earth, from four
different nearby locations, for testing, which will take about a week.
Choosing the Stabilizer: For added strength and waterproofness, a
stabilizer is added to the compressed “earth concrete” blocks. If the
earth to be compressed into blocks in the presses has ~30% sand,
>20% silt, >30% clay, with the rest small gravel, then cal (lime) can be
used; if the earth mix has ~50% sand, and <20% silt and <30% clay,
then cement is used. One advantage of cal (lime, calcium hydroxide,
Ca(OH)2) is that over time it absorbs CO2 from the atmosphere,
converting to calcium carbonate (CaCO3): this makes cal nearly
carbon-neutral, as the CO2 liberated during the firing process is reabsorbed. From the practical standpoint, we have to consider
strength, the cost of adding clay versus using cement if the soil is
sandy. Analysis of the soil, and the production of test blocks will give
us the information we need in order to choose the correct stabilizer for
our needs.
~~~
Mud, used for eleven millennia, remains today the building material
most widely used worldwide. A third of humanity lives in earthen
homes, more than two billion people in 150 countries. The
architectures of earth, simple and monumental, are present in various
contexts and meet diverse needs. Source: CRAterre, the Earth
Architecture School of the University of Grenoble, France
Ancient Stabilizer Usage: Richard and Antonio talked about how
the Aztecs mined calera (limestone), fired it to produce cal (lime),
mixed it with earth, and pounded it to produce plazas that are still
existing today. Mike has worked on archaeological sites in Belize,
where they have been able to gauge the relative prosperity of the
people by the thickness and amount of cal present.
Since 1979 CRAterre has recognized that earth is a material that meets
the challenges of environmental stewardship, maintaining cultural
diversity, and elevating people out of poverty. In this perspective,
CRAterre has three objectives:
• best use local resources, human and natural
• improving housing and living conditions
• valuing cultural diversity
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Our Mission: harness appropriate technology to create building blocks for a sustainable future, on an
ethical foundation, through education in the conscious utilization & transformation of local resources
¿Do You Bamboo?
Contacts and Links:
When imagining a type of portable
structure to erect over the blockyard,
for shade and shelter from rain, what
came to mind was using thin walled
electrical conduit tubing, or rebar, or
PVC pipe, you know, all those
manmade materials that I am familiar
with . . . and then someone said why
not use bamboo. Of course! Why did
I not think of that? I love bamboo,
and it appears that a lot of other folks
do too.
Sayulita Tierra Firma email: [email protected]
Project Manager & Principal Investor: Richard Presley
Email: [email protected]
Cell: 322 191 2007
Auroville Earth Institute: www.earth-auroville.com
Instituto Tierra y Cal: www.tierraycal.com
TierraLuz (eco-development): www.landinsayulita.com
Costa Verde School: http://www.colegiocostaverde.com
CRAterre: http://craterre.org/
~~~
Teaching the Children, teaching Ourselves!
Bambúes de las Américas, Bamboo of the Americas,
(http://www.bamboooftheamericas.org/index.php) is a non-profit
organization with a focus on the conservation and intelligent
use of bamboo.
Children on a fieldtrip,
exploring the art of
constructing arches,
vaults, and domes, at
the Earth Architecture
School, CRAterre, in
Grenoble, France.
So, the idea arose that we can make lightweight arched
trusses by driving rebar stakes into the ground to use as a
pattern, springing bamboo inside the stakes, and then lashing
the arches together with triangulated struts. After the first truss
is made, we
can easily lift
it off the
pattern,
make another
one,
repeating the
process until
we have
enough for
the shelter
length we
wish to span.
Their teacher here,
Satprem Maini, with
his back to us in the
photo, is the founder
and director of the
Auroville Earth
Institute, and is one of
the foremost experts
in the world. The
team led by Satprem
created the Auram 3000 block press, (which we have here in
Sayulita): with interchangeable molds it can create ~75
different type of blocks, supporting beautiful functional
architecture with complex geometries based on classical
elements and forms.
To erect a structure we can drive rebar stakes into the ground
every few meters to form a rectangle, with the rods sticking up
above ground ~1/3-meter. Then we can burn out the dividing
membranes in bamboo poles with a hot metal rod and jam the
hollowed out pole ends over the rebar stakes to support the
trusses. Add longitudinal bamboo stringers, triangulate with
twine for rigidity, cover with tarps and/or fronds, and that's it.
Truly, getting ones hands dirty, practicing organic gardening,
revitalizing the earth through permaculture and afforestation,
and creating earth houses, is good for the heart, is good for us
all. Fostering an ever-awakening awareness of our precious
relationship with life on earth is a noble legacy for our children.
The idea is to construct, durable, lightweight, portable shelters
that can cover the blockyard during block making and be
erected on the site building site to protect masons when they
are laying walls during construction. Or any other purpose.
It's worth trying, yes?
~~~
Sayulita Tierra Firma Earth Blocks is one seed of a global idea
that has found good local soil in which to grow. If you would
like to participate, support, or know someone who would; if you
are a builder, contractor, or are thinking of building, kindly
spread the word, and please do get in touch . . . let's work
together to build a better future.
So, if anyone knows where we can harvest some bamboo
(especially for free) please let me know!
~~~
~~~
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