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If
You Want to Save the Earth, Build Your House With It!
By
Thomas Hirsch
What I find the most satisfying and exciting these days as a builder of
over twenty years, is working with abundant, locally available natural
building materials. In our
case here in Northwestern Lower Michigan that means clay, sand, stone,
straw and timber (from sticks to the big stuff).
I do not have to chase to the lumber yard and run up my tab, pay
for far away transportation costs, dispose of packaging material, expose
myself or my clients to toxins, nor worry about leaving a legacy of
non-biodegradable substances in a landfill or the building itself.
Our
company, Harmony Home Construction, is pleased to be furthering the
renaissance of “Leichtlehmbau” (pronounced lysh-lemb-ow)
or Light-Clay Building, a German method using a mixture of straw
and clay for infill between timbers.
Almost every culture has variations of this method using earth and
some fiber to create a wall system. There
are examples of centuries old, continuously inhabited structures
throughout Europe, Asia and the United Kingdom.
It is estimated that approximately half of the world’s population
live in buildings made from earthen soils.
In
Leichtlehmbau, straw is bound together by clay and provides the thermal
resistance or R-value. Clay
is mixed with water to a creamy viscosity called “slip”.
This clay slip coats the straw and provides protection from mildew,
moisture, vermin and fire. Using wooden forms this mixture is pressed and tamped into
the wall cavity. The walls
are covered, when fully dry, with clay-based plasters or other siding
materials. As with any
building method, attention to details such as the foundation, drainage,
roofs, flashing and finish surfaces are a must.
Time
after time I stumble upon historical references to the use of straw and
clay in building. I
understand that portions of the Great Wall of China were made of
straw/clay hand tamped between form boards.
The Ancient Egyptians used straw/clay blocks in the building of
many beautiful structures. Native
Americans were known to sink poles into clay to protect them from rotting.
There was a timber frame barn in Wisconsin, built in the 1800’s,
that had walls made from straw clay infill.
Notably, upon examination, there was no evidence of wood rot
anywhere the clay mixture came in contact with the timbers.
The historical literature shows numerous examples of beautiful
“ancient” structures still standing and functional, using these
natural methods.
Earthen
walls provide thermal mass qualities that regulate temperature and
humidity and absorb odors. These
walls help diffuse electro-static buildup in the air.
They provide a permeable wall system that becomes a passive
heat-exchanging/air filtering medium.
Our walls are twelve inches thick, weigh approximately 40-60 pounds
per cubic foot and range from R-1.8 to R-2.0 per inch, depending on the
ratio of straw to clay. If
these buildings ever become unusable for some reason, they can easily be
composted or disposed of without damage to the earth.
Earthen
based wall systems lend themselves to owner involvement, as they are
relatively low-skilled/labor intensive and low in material cost to build. If
properly built, the net result is a healthy house utilizing lower total
embodied energy ( ie; less stress on the earth and her resources). Clay is a very abundant building material and straw fibers
are a readily renewable resource. Both
are non-toxic when clean. Other
earth building techniques with a growing popularity are cob, adobe,
straw-bale, rammed earth and wattle and daub.
These systems lend themselves to sculptured forms, curves and
niches. I enjoy and think so
highly of them that my wife and I built a second story on our home made of
straw/clay walls with earthen plasters.
At
Harmony Home Construction, LLC, we frequently offer the opportunity for
anyone to experience straw/clay wall stuffing first hand. Mud
pies, anyone?
Consult
our website www.harmonyhomeconstruction.com
or call for more information.
Hear ye, here ye!
Come one, come all!
This is your chance to
do Leichtlehmbau!
We’re stuffing our
walls with straw and clay.
And you are invited to
come and play!
Resources:
Earth
Building and the Cob Revival: A Reader,
third edition, 1996 The
Cob Cottage Company, P.O. Box 123, Cottage Grove, OR 97424
(541) 942-2005, www.deatech.com/cobcottage
The
Cobber’s Companion, How to Build Your Own Earthen Home,
Michael G. Smith
A
Cob Cottage Publication (see above)
The Natural House
Book: Creating a healthy,
harmonious, and ecologically-sound home environment,
David Pearson, Gaia Books Ltd., Simon and Schuster Inc., 1989
Natural
Home magazine,
201 E. Fourth St., Loveland, CO 80537-5655
(970)
669-7672, www.naturalhomemagazine.com
The
Art of Natural Building, Design, Construction, Resources,
Kennedy, Smith & Wanek New
Society Publishers, 2002
Prescriptions
for a Healthy House,
Paula Baker-Laporte, New Society Publishers, 2001
Harmony
Home Construction, LLC.
8122 Barney Road
Traverse City,
Michigan 49684
Ph: 1-877-45-GREEN Fx: 231-932-9193
info@harmonyhomeconstruction.com
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