Wall Street Journal has brought to our attention that plastered straw bale walls have been proven, now, to be a fire- safe envelope for both residential and commercial buildings. Engineer and straw bale advocate Bruce King
recently paid for an insurance-required test of fire resistance of straw bale walls, whereby "workers fired up a super-hot gas furnace next to a wall stuffed with straw in hopes of calming skittish insurers, bankers and building inspectors who have been reluctant to embrace big buildings insulated with bales of dried grasses". The test wall satisfactorily withstood over two hours of 1,700-degree heat and the following hose-down. Here's a listserve announcement
from pleased onlookers. From the WSJ article: "Inch for inch, straw bales insulate about the same as fiberglass, but because they are so much thicker than typical rolls of insulation, they provide a stronger shield against heat and cold. Straw bales often are procured from local farms, reducing pollution that comes from transporting construction materials, a key concern of green-building advocates. Straw is also easier to dispose of because it's biodegradable."
It would be nice to go away from this post believing that a major barrier to eco-efficiency has fallen. But, we don't think positive change will come that easily. There are vested interests, distributors, trade groups, organized labor, insulation maufacturers to name a few, which will advocate against the spread of straw bale by any means available ( "rats and mold, my little ones.").
Objectively, there is a logistics issue to be addressed next. "Home centers" were not designed to stock straw bales. Bales are space intensive, and can't be safely kept in overhead bins. If straw bale construction were to become commonplace, then, retail and commercial supply chains would have to be transformed.