Straw Bale Construction Passes The Fire Test
by John Laumer, Philadelphia on 08.10.06
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.
Logistics have to be changed? So what; business is nothing but an ever ongoing change!
Strawbales have been used more often; I recall (vaguely) a shelter for protesters against nucleair arms in the netherlands. They used raw straw wrapped in plastic, but I can imagine more sustainable solutions can be designed. And maybe, for an alternative lifestyle, a building could be constructed along an iglo-concept? Good thing this man has come this far with his urge prove the possibilities of straw!
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Well, yes. I agree philosphically. And congrads of course are due.
I seem not to have communicated well with my most important point, though. What are WashingDC and State's Capitals but swirls of coporate advocacy? Want to stop the loss of insulation sales at the home center? Have the township declare storage of hay to be a fire hazard. And so it goes. These tactics won't last forever but certainly can delay progress for decades. Think how hard it is to get industrial hemp fiber legal if you need an example.
Use of the term logisitics refers then to how bales will be produced, delivered, and stored for the trade. These are the areas where negative advocacy will be leveraged.
Whats with all this conspiracy theory crap, thinking there would be action against straw bale housing? Sheesh if it works the it works, the standard fiberglass insulation comapnies are not standing in a corner in fear because they might lose some market. Blown newspaper insulation was not blocked, in fact they sell that too.
Now rant done, I thought these could only be done in warm climates. Anyone know if they stand up to winters? I suppose straw is rot resistant. And ones I saw made were covered in concrete.
You'd think with all the asbestos lawsuits from the 60s fiberglass insulation companies are still dealing with, they'd be too crippled to fight for their interests in congress...
guess not, eh?
Yes, straw bale holds up very well in cold climates. There are quite a number of them in Canada, and some northern European countries. As well, there is an excellent certificate course run at Fleming College in Haliburton, Ontario. There was an article here on Treehugger about a month ago, relating to the course. You can check out any info about this year's course at http://www.sustainablebuilding2006.ca.
Now what straw building needs is a PSS feature. Say a company selling necessary machinery, information and instructions. Then it could be harvested and processed locally. Straw is available all over the world and has been used in northern countries such as Denmark for ages as insulation.
one friend of mine that advocates bale houses or rather is fairly high up on his wish list says that the problem in any climate is to shield the bales from water especially rain. So the bale needs to be covered on the outside with something water tight while allowing ventilation.
true that sellers probably want to prevent it but that is true for any new technique or product. constructors probably always wants the cheaper material although bales probably are a lot more work intensive than rolls of insulation? but then the user of the house seems to have very little choice if he/she has little to say in the design of the house (and of course has to pay the electricity bill and other maintenance costs).
Straw Bale Construction is a fantastic option for almost anyone. The homes perform extremely well in both hot and cold climates. The biggest concern with straw bale houses is not water, but moisture. There is a difference in the way I speak to these. Water, in the form of rain for example, can be easily designed out of the equation. Large overhangs and proper use of gutters can completely eliminate the impact rain has on a house. Moisture, in the form of humidity on the other hand, cannot be designed out of the picture. Humidity moves through everything and if a relative humidity is too high and stays high, the bales will be at risk of rot and mold. One way to deal with this is to install a de-humidifier in the home. In some cases, however, building with bales is simply not a good option. I tell most people that I work with that they have a great climate for SB construction. I tell the few in the high humidity areas of the World (i.e. highly tropical climates) to think about other options. You can find out all kinds of information about green building and straw bale construction, including new tips and techniques for building with bales at my website www.StrawBale.com. Please visit and post a question there too if you have one.
Happy Baling,
Andrew Morrison
Strawbale is not bad but it is nothing without wood or steel to structurally support it. And, what do you do about roofs or floors (default to conventional methods).
Further, the only thing that gives any kind of fire resistance is concrete or drywall. Like putting lipstick and earrings on a pig, it's still a pig!
You're entitled to build and live in any manner of house you choose but no need to spread misinformation. By the way, I'm in Southern California. We're known for earthquake activity, scrutinizing building departments and pretty smart energy examiners, not to mention small lots.
I have been building straw bale homes now for 10 years in Ontario, Canada. Last year we hosted the international straw bale building conference in Ontario, where we met & worked alongside builders from Sri Lanka, the U.S., New Zealand, Australia, China, and Europe. Straw homes are being built all over the world, where climate permits (as Andrew Morrison points out, in some exceptionally humid climates, building with bales may not be viable).
John Laumer's posting, which sparked these other comments, mentioned fire testing done by Bruce King. Fire testing has actually been done all over the world, and many of these tests are listed in Bruce King's new book, 'Design of Straw Bale Buildings'. This book has chapters on moisture, fire, insulation ratings, structure, codcs & standards, and is a must have for anyone interested in current research on straw bale construction, with contributions by experts from around the world.
One of the advantages of having straw bale building be at more of a grass roots level is for the sense of community involvement. Building a straw bale home generates a lot of excitement from friends and family, and people love to come and volunteer with both the stacking of the bales, and with plastering. A weekend bale raising is reminiscent of the old time barn raising, where friends & family gather to build your home, followed by celebratory meals at the end. Once upon a time we didn't hire all of the labour for our homes...we built them within our communities!
That being said, straw bale building is starting to appear in more 'sustainable' developments, and some companies are producing pre-fab straw bale panels that can be assembled on-site. Not exactly mainstream, but definitely growing! Bale buildings can be as organic and funky as you want, or you can achieve a more modern look with sleek lines.
Raul is correct in his posting that unplastered straw bales are flammable, and they get their excellent fire rating once plastered on both sides. It is common to plaster both sides of the bales with an inch or an inch and a half of any of the following: an earthen plaster, a lime plaster, or a 50/50 lime/cement plaster.
I'd like to point out that a plastered straw bale wall can indeed be load bearing (ie, structural); in fact, the origins of building with straw bales began in Nebraska, and the 'Nebraska technique', as it is known around the world, utilises bales in a load bearing capacity. There are still 100 year old load bearing bale buildings being used in Nebraska.
Once a year, there is a tour of straw homes across the province of Ontario, organised by the Ontario Straw Bale Building Coalition (www.strawbalebuilding.ca). This offers the general public the opportunity to see a variety of designs, and to talk to homeowners about the pros & cons of their straw home.
If you'd like to see more of what Camel's Back Construction has done in Canada, please visit www.strawhomes.ca
cheers,
tina therrien