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Straw Bales as a Building Material
Bales have been used as a building material for centuries. In the United States,
pioneers settling the Great Plains region built with what they had at hand –
prairie meadow hay and later straw. As the railroads spread across the prairies,
more conventional building materials, such as wood and later steel became the
norm. An enormous amount of crop residues (straw from wheat, oats, rye, rice,
among others) were often turned back into the soil, left to rot or were burned.
In the 1990s when plowing these residues back into cropland became cost
prohibitive and the burning of crop residues became an environmental hazard, new
markets for straw were explored. About the same time, efforts to find a simple
and economical building method that people could do themselves was also being
researched. And the revival and resurgence of bale building started.
The first bale buildings were small structures designed and built by the owner.
Nothing more than the space they needed, simple structures using materials they
had at hand - just like the prairie pioneers. Bales are used for all types of
buildings: commercial, industrial, agricultural, businesses, government
agencies, transportation and storage, schools, churches, workshops and garages,
affordable to custom housing.
Many methods of bale construction are used. The Nebraska-style load bearing
method came first, then post-and-beam and many variations of it – pole and round
wood, timber framing, box column to name a few. Now builders are developing
structural insulated panels (SIPS) with bales as the infill, some are preparing
building kits; others are experimenting with compressed straw products both
insulative and structural.
Bale building makes sense – it is economical, energy efficient, easy-to-build,
durable, comfortable and quiet. Walls are about 10 percent of a building’s cost;
at $5.00 per bale plus storage and transportation, bales are economical. Finding
bales as close to the building site as possible adds to cost savings. With an
average insulation value of R-30, bale walls hold indoor temperature at 60 to 75
degrees year round with only a simple back-up heating and cooling system needed
for the hottest or coolest days. Natural ventilation and control of humidity
will add to the building’s overall comfort and maintenance – good indoor air
quality and management of moisture. Utility cost savings have been reported as
high as 20 to 40 percent. Ease of building comes with simplicity of design and
the use of the right method for the project. Bale buildings have proven their
durability by withstanding severe weather and the test of time. The 16- to
18-inch thick walls create comfortable and secure-feeling interiors with good
sound insulation.
Testing and research on all aspects of bale building - fire, moisture, wind,
seismic stability, bale compression – all using various structural methods and
wall coatings – have been completed and continue to be done as new methods and
materials come into use. Codes have been written and adopted; insurance,
financing, and professionals are available in almost every setting. Bale
structures can be built in all climates and can be found throughout the U.S.,
Canada and nearly every country around the world.
Joyce Coppinger is the Managing Editor of The Last Straw Journal and can be
contacted at
www.thelaststraw.org or through the TLS blog at
http://thelaststraw-blog.org. You can also visit
http://sbregistry.greenbuilder.com for more information. |