Straw-bale construction

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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 system because of its cost and easy availability[1], and its high insulation value[2].

Although grasses and straw have been in use in a range of ways in building since pre-history around the world, 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 Nebraska, where grass was plentiful and other building materials (even quality sods) were not.

[edit] Methodology

Straw bale building typically consists of stacking a series of rows of bales (often in running-bond) on a raised footing or foundation, with a moisture barrier between. Bale walls are often 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 cementaceous mixes, lime-based formulations or earth/clay renders. Bale buildings can either have a strucural frame of other materials, with bales between (simply serving as insulation and stucco substrate), referred to as "infill",or the bales may actually provide the support for openings and roof, referred to as "load-bearing" or "Nebraska-style", or a combination of framing and load-bearing may be employed, referred to a "hybrid" straw bale.

Typically, bales created on farms with mobile machinery have been used ("field-bales"), but recently higher-density "recompressed" 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 more. And the basic bale-building method is now increasingly being extended to bound modules of other often-recycled materials, including tire-bales, as well as those of cardboard, paper, plastics and used carpeting, and to bag-contained "bales" of wood-chips, rice-hulls, etc.

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[edit] List of Straw-bale construction builders and resources

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Wikibooks has more about this subject:

Straw Bale Construction

Australia

Huff 'n' Puff Strawbale Constructions

Canada

Amazon Nails - includes long pdf document about straw bale building in UK.

United States

Arm of the Spiral was created to promote the fusion of sustainable and natural building methods and provide encouragement to the would-be owner/builder.