By Chris Magwood
An important concept to understand when considering moisture and building materials is adsorption. Moisture in vapor form infiltrates any and all materials. The surface of most materials will offer individual water molecules an electrically charged attraction, and the water molecules will “stick” to all available surfaces. The makeup of plaster and of straw bales offers a vast amount of surface area for this adsorption. Plasters are full of micro-pores and straw has great deal of available surface area as well as micro-pores in the hollow stems. Together, these materials allow a surprisingly large amount of moisture to safely adsorb onto/into the materials without the water molecules accumulating in sufficient layers to become drops of liquid water. Bales and plaster can hold a remarkable amount of moisture in adsorbed form. “For a 8 pcf (pounds per cubic foot) bale, more than 1 pound of water (approx. 1/12 gallon or 0.46 liters) in vapour form can safely be stored per square foot of wall area” according to John Straube in Building Science Digest BSD-112. This explains why the walls can perform so well as “vapor open” or “vapor permeable” systems.
by Chris Magwood
The straw bale revival of the 1990s reintroduced builders to a pioneer building method that showed remarkable potential for building in a modern context. The nature of the basic components of a straw bale wall system – bales with plaster applied directly to bales – combined several obvious [...]
On October 3, 2013 the International Code Council (ICC) approved final action RB473-13 as a new Appendix R in the upcoming 2015 version of the International Residential Code (IRC).
The approval marks the latest advance of straw bale construction in the building codes and permitting process. It is the highest approval to be granted for [...]
By Michel Couvreux
Thanks to the hard work of a few, Natural Hydraulic Lime has become one of the materials of choice for restoration/preservation projects and natural building construction in the United States.
Suddenly realizing the great potential of NHLs in the US, and feeling the economic hardship abroad, several European manufacturers have begun to [...]
Update: The Feuillette House has been purchased by the Centre National de la Construction Paille. They are still in need of support to complete their plans for creating a visitor center at the historic site.
While Nebraska makes the claim for the origins of bale construction, the French have an excellent example of historic [...]
By Duncan Lithgow
Straw Bale Building in Holland (Courtesy http://en.wikibooks.org/wiki/Straw_Bale_Construction)
I love open content shared with everyone and improved by everyone. So back in 2006 after I was at the International Straw Bale Builders Conference here in Denmark I agreed to collect all the minutes and other documentation for the conference. I made this [...]
The Straw Bale Alternative Solutions Resource is a document prepared by the Alternative Solutions Resource Institute (ASRI) addressing, obviously, bale construction. While the goal of ASRI is to “foster and facilitate the use of natural materials and systems in the construction of buildings…” this document is meant to focus specifically on bale construction and how [...]
This article originally appeared in TLS #55 and was the feature article in that issue.
by Wayne Bingham and Colleen Smith – Idaho, USA
Our interest in straw-bale construction grew out of our concern for energy efficiency. Our research into building energy efficiency grew into an awareness of sustainable building practices. An urge to build [...]
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The Last Straw has undergone a transition over the past [...]
This article appeared in TLS issue #42. This issue includes articles about experimentation and development of bales made from various types of materials. Articles about methods and equipment for spraying bales with plasters appear in #43 Spraying Earthen Plasters in Colorado), #33 (Stucco Pumping Iron).
by Peter Mack – Ontario, Canada