Tuesday, May 6, 2008

Build with straw bale in Maine?

HI there Mick

I found your name on the web while doing a search for straw bale construction in Maine.

My partner, XXXX and I are getting ready to build again yes at the ages of 60 and 66! We have a bit of land in XXXX and want to build as off the grid as we can We also love straw bale, but haven’t been able to find out where to get straw bales anywhere near here We thought perhaps you could give us some leads Do you know of any local farmers who grow and bale straw and will sell it ?? any hints you can give us will be much appreciated!

Meanwhile Happy Spring!



I should start off by noting that Aimee and I are both scientists, not straw bale advocates, so we do objective reporting on our work, including domestic experiments. We have been gently advising homebuilders against building with straw in Maine now since we got done with our bale house experiment. The main reason is the lack of suitable cheap bales, and the fact that you will almost certainly have to build a straw-wrap house, rather than a "Nebraska style." Because you will have to build some kind of timber frame to support the roof, and because straw is expensive and has to be trucked far in Maine, there is no great cost savings and there are increased climate emissions. In particular, we paid up to $7 a bale, and the lowest price we got, at $2, was for very few bales. I would expect to pay an average of $3.5 for a 40-50 pound bale.

To my mind, these facts negate the whole argument for straw -- that it's a cheap locally-produced product for both structure and insulation that would otherwise go to waste. Straw is neither particularly cheap nor locally produced in Maine. It's also labor intensive, particularly at the plastering stage, and labor is not cheap, while plastering skill is hard to come by.

You will discover additional difficulties with insurance and possibly building codes enforcement, none of which are necessarily insurmountable, but it makes little sense to take them on considering the above. There will also very likely be difficulties later with critters in your walls.

If instead you used cellulose (a fully recycled product) or recycled foam board insulation, or both (see below) you would get the insulation benefits, reduce costs, avoid critters and codes-enforcement officers, and be able to insure your home for less.

Cellulose is R3.8 per inch. An 8-inch stud wall cavity (really 7.5 inches) filled with cellulose (on 24-inch center) is R28.5. Two inches of recycled polyisocyanate or urea formaldehyde foam board on the outside of the sheathing adds around R24, providing R52.5, enough insulation for a passive solar house. These specifications, carried out by a proper contractor, are suitable to pass muster as a "normal" home with insurance companies. If you home build, you may have to use "surplus lines" insurance, but the costs per unit coverage will still be less than for a bale home.

Some natural builders balk at using either kind of insulation, worried about venting of toxic chemicals contaminating room air. The fire retardent in cellulose is borax, which is toxic, but doesn't actively vent in any toxic form, and will in any case be behind drywall. The recycled foam board will be fairly stable, because it is old, and any venting will be to the outside, not inside.

Having noted all this, I will mention that our advice generally has little effect on prospective home-builders who are already commited to straw bale. This seems to be one of those cases of advocacy or possibly religion defeating science.

If this is the case, straw bale vendors can be found, and with luck you may get a good price. The best chances are found with hay dealers who make a living trucking hay from regions where it is in surplus, such as Aroostook County, to places where it is in shortage, such as the suburban Boston/Portland region. Hay dealers can usually find straw bales too, and a tractor-trailer load can be easily arranged in season.

The dealer I use is Mr Beem of Beem Farm in Newport, Maine.

I have written this information out several times in the past few years. I hope you don't mind if I post this email to my blog so I don't need to do so again.




  1. Just found your blog today while looking for others similar to my (and wife) own. Couldn't resist commenting on the straw bale construction. It is a shame that straw just isnt grown that much in Maine. The company I work for has had a couple projects that we are using ICF blocks. The one's we are using are called Durisol, and are made from recycled wood bound with portland cement. They have insulation on the inside cavity as well. Pour in the concrete every 4' or so and you've got one heck of a wall. I'm gathering that folks who like the idea of straw bale in some way like it because of the plaster on the outside. The Durosol is great for that. If I was a DIYer putting up my own walls I'd use the styrofoam ICF blocks, much easier to handle and the inside framing is almost always made to have rebar just popped right in. Anyway, that's my 2 pence worth. Off to go read up on the back logs now...

  2. IMHO Straw makes lots of sense in Maine. I had no trouble securing 600 bales from Beem farms at $3.50 (including winter storage) to build our straw bale home in Palmyra. The insulation value, the look, and the low maintainence all contribute to its attractiveness. The key factors in building an inexpensive home are: size, sweat, utilities, materials.

  3. This has been done, although the mortar used is usually clay-based.

    See “Serious Straw bale,” a how-to book, for details. If your local public library doesn’t have it, you can get it through Interlibrary Loan.

    Generally my wife and I advise against using any straw bale building material in Maine based on our experience of high costs versus other insulation particularly recycled products.

    You can read an article about this here, with several interesting comments.


    On 10/1/08 10:45 PM, Ed XXXX wrote

    Hi Prof. Mick Would like to ask your thoughts on following

    Why couldn't Straw bales be pre-coated with Lime/plaster prior to construction much like concrete building blocks ???

    In my case I would love to construct a " Straw Bale House on a flat roof that joins and old Brush Mill in XXXX Me. ~~ The walla would be non load bearing and I would probably use clapboard outside walls to match the rest of the building ???

    Any comments appreciated and nice article they wrote on Your family home up the coast !


  4. Greetings all easterners, jan 09

    Just happen to be searching and scanning east coast straw news as I'm originally from Boston and have been considering a renovation project for my parents who reside in Newton, MA. I mostly plaster (earth, lime, gypsum) SB homes out here in Colorado and I do some building as well and all prep. Just putting this out there if anyone is uncertain about earth plaster and would like to hire me for any project they may have. I've done some very high-end projects in Boulder and elsewhere and I primarily work as a sub-contractor but the work I do is on a flexible basis and far far, far less expensive than the typical contractor. Email me with any questions as I could be willing to make a trip to my old stomping grounds of ME and MA for a work/family long-stay vacation. Generally labor is very high but it's interesting to see the complaints about material cost. How big are we making those houses??? I'll agree that the bales could be a challenge to locate but Canada isn't that far (not much further than getting bales from central CO if you live in the Denver area?) Regardless I shouldn't advise on this issue much but building with bales can be very cost efficient if you're willing to take your time and do some work yourself. Are we trying to build quick stick houses or houses that will last and please the soul?? Plastering is very easy to learn although not always an easy job, actually it's a lot of work. As for materials? dirt, clay, chopped straw, sand and some water throw-in some pigment and it looks great. You might even be able to dig much of this around the home site? How about slip-straw or light clay straw? My advice, if you're seeking to keep the toxins out, go with straw (even in Maine!) and earth plaster. As for critters? They tend to hang around during the build phase, in your bales and towards the end of plastering they tend to have less places to hide so you tend to see em more often but after a few traps and after all is sealed it's a done issue. wtf people? So, any questions drop me an email maybe we'll meet one sunny day in Maine....that is, if they have any sunny days in Maine?
    Ken eatbikenap@hotmail.com
    ps Bush is out, straw is in!


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