Straw-bale construction

"“Straw bale construction is at once an American invention and a sustainable answer to housing needs on and off the reservation.”"

— Rick West, Director, Smithsonian Institution, National Museum of the American Indian

Straw-bale construction is a building method that uses straw bales as structural elements, insulation, or both. It is commonly used in natural building. It has advantages over some conventional building systems because of its costFact|date=July 2008 and easy availabilityFact|date=July 2008, and its high insulation value. [Canada Mortgage and Housing Corporation. [http://www.cmhc.ca/publications/en/rh-pr/tech/tech02-115-e.html "Energy Use In Straw Bale Houses"] . Retrieved on 2008-09-04.]

Although grasses and straw have been in use in a range of ways in building since pre-history around the worldFact|date=July 2008, their incorporation in machine-manufactured modular bales seems to date back to the early 20th century in the midwestern United States, particularly the sand-hills of NebraskaFact|date=July 2008, where grass was plentiful and other building materials (even quality sods) were not.

Method

Straw bale building typically consists of stacking rows of bales (often in running-bond) on a raised footing or foundation, with a moisture barrier between the bales and their supporting platform. Bale walls can be tied together with pins of bamboo, rebar, or wood (internal to the bales or on their faces), or with surface wire meshes, and then stuccoed or plastered, either with a cement-based mix, lime-based formulation, or earth/clay renderFact|date=July 2008. Bale buildings can have a structural frame of other materials, with bales simply serving as insulation and stucco substrate, ("infill" technique), which is most often required in northern regions where the potential snow-loading can exceed the strength of the balesFact|date=July 2008. Alternatively, the bales may actually provide the structural support for the building ("load-bearing" or "Nebraska-style" technique). A combination of framing and load-bearing techniques may also be employed, referred to as "hybrid" straw bale construction. (cite book |last= Myhrman |first= Matts |coauthors= S.O. MacDonald |title= Build it with Bales |publisher= Out on Bale |year= 1994 |isbn= 0-9642821-1-9 )

Typically "field-bales", bales created on farms with baling machines have been used, but recently higher-density "precompressed" bales (or "straw-blocks") are increasing the loads that may be supported; where field bales might support around 600 pounds per linear foot of wall, the high density bales bear up to 4,000 lb./lin.ft. and moreFact|date=July 2008. The basic bale-building method is now increasingly being extended to bound modules of other often-recycled materials, including tire-bales, cardboard, paper, plastics, used carpetingFact|date=July 2008. The technique has also been extended to bags containing "bales" of wood chips or rice hullsFact|date=July 2008.

ee also

Notes

Further reading

*"Design of Straw Bale Buildings". Bruce King. Chelsea Green Publishing, 2007.
*"More Straw Bale Building: A Complete Guide to Designing and Building with Straw". Chris Magwood. New Society Publishers, 2005.
*"Straw Bale House, The". Steen, Steen, Bainbridge & Eisenberg. White River Junction, Vermont: Chelsea Green, 1994.
*"Building a Straw Bale House". Nathaniel Corum. Princeton Architectural Press, 2005.
*"The New Natural House Book", Pearson, David, Simon & Schuster, 1989, ISBN 0-684-84733-7.

External links