Strawbale home

Realize that some of these techniques are very specific to certain areas and climates. For example, straw bale construction makes good sense where you have a dry climate. In a humid climate the straw rots, even when protected by adobe.

In other cases certain areas are better for some techniques because materials are more readily available there. For us, granite is easily acquired for free or close to it. That makes building with stone a good choice and stone holds heat very nicely as well as not leaking (water holds heat better but goes algaey and leaks).

We built an extremely energy efficient small home that keeps itself cool in the summer and warm in the winter. We burn very little wood, no other heat besides the passive solar coming through the windows. The trick was balancing the thermal mass against the energy gain and loss. Our house has about 100,000 lbs of stone, brick and concrete inside an insulating envelope which is then inside another envelope of adobe to protect the insulation.

See here for details:

http://sugarmtnfarm.com/blog/labels/Tiny%20Cottage.html

of various posts I've made about the building of our house. The neat thing is not only does it cost virtually nothing to maintain and cool/heat but we spent less than $7,000 building it.

Cheers

-Walter
Sugar Mountain Farm
in the mountains of Vermont
http://SugarMtnFarm.com/blog/
http://HollyGraphicArt.com/
http://NoNAIS.org

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How can a straw bale house be fire safe?

the bales are packed so densely that fires usually smolder. it's like trying to light a closed dictionary on fire.

That, and it's encased in stucco on the outside and plaster on the inside.

Normally, this is about the time in a strawbale thread when someone asks, "Hasn't anyone in this forum read the Three Little Pigs?"

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Exactly: it's not that the bales wouldn't eventually burn, once flames got past the concrete stucco or plaster, but they would take so long to do so that you'd have to be dead drunk for a few days to not manage to get out of the house in time. By contrast, all that nice kiln-dried, tindery stud construction would go up in flames fast -- as we all know from burning construction scrap in our woodstoves.

I live in the woods. There are termites everywhere because there is rotting wood in the forest. (Actually, they seem to sort of "bloom" at certain times of the year.) You think a wood structure is immune from termites? I bet there's a whole load of exterminators who would argue with you on that one -- they make their living on the many stud houses, not on the very rare strawbale houses.

I have moisture meters placed in the four walls of my house at about 4 inches above floor level. Today, the north wall, which in 10 years has never seen sunlight in the damp woods of this damp county of the Pacific NW -- and if you have watched the news you know we've been having a lot of rains and flooding this week -- registers between 11 and 12% moisture. No "special effort" has been taken to keep the straw dry, beyond common prudence during construction, such as having a moisture barrier at the floor level -- I think it was a bit of plastic or tar paper on the wall bottom plates (is that what they're called?) -- and having 24 inch eaves/overhang.

Excuse me, but I did not say that a wood structure is immune to termites. Not only do I prefer to stay away from straw bale, but wood as well. It is bug food and fire fuel, plus the R value is not great.

I have found live termites on my mountain property 3 times. I have a fundamental understanding and I suspect you are on a different page. I have done termite jobs on top of a 14000 ft mountain, as well as all over Denver. Celulose and moisture are critical elements in their world. No criticism of you.

Is that why your handle here is "gobug"?

go are my initials, and you guessed the rest. I created the moniker, and kept it for 15 years now.

I have been on an open prairie in CO without a plant higher than my knees as far as I could see. I found a discarded 2x4 and it had live termites. Since their radius of activity away from their nest is about 100 yards, and there was nothing but grass, it is apparent that they eat not only wood, but grass, hay, and straw as well. In CO there are only 5 different kinds of termites. Only one does enough damage to harm structures using wood, which is partly why CO will not allow strawbale structures without a "pole beam" system to support the roof.

Architecturally, there are excellent homes which have been made of strawbale, cob, cinderblock, adobe, rock, even 2x4x8's. I like strawbale because it lets me out of the box (the most likely shape possible from conventional (2x4, 2x6, 2x8, 4x4x8, 4x8 etc), off the shelf, materials) Still, my years of experience with pests and the lack of ancient strawbale structures leads me away.

How "ancient" does it have to be?
(In light of the fact that balers have only been around 100 years or so)

We used to neighbor Fawn Lake, and the headquarters building was built around 100 years ago with bales. It's still in use.
I don't know if Pilgrim Holiness is still in use but I do know it's still standing strong.

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~*~Erin~*~
SAHM, ranch wife, sub and quilt shop proprietress
the Back Gate Country Quilt Shop

I think we'll have to wait a while before there are any 'ancient' strawbale homes. Baling machines were only invented a little over a hundred years ago -- and there are some structures still standing in Nebraska which are nearly that old. Nebraska isn't really a desert climate, either.

I've looked into building with bales, and may someday. Our county building department seems to be all for it -- I've talked to them about it. They said there are several strawbale structures in the county already, and they'd be glad to see more. So check in your area before assuming that they won't allow it.

Kathleen

Though the Sandhills are considerably dryer than eastern NE. Figure 14-18" annually.

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~*~Erin~*~
SAHM, ranch wife, sub and quilt shop proprietress
the Back Gate Country Quilt Shop

We live near the coast of Texas and I know of one straw house for sure within 8 miles of me. In 2001 we built a Heritage All-Steel home out of Arkansas. I saw the ad in our Texas Coop Power magazine. We roughed in the plumbing ourselves, constructed it ourselves, framed it, etc. We did approximately 75% ourselves. The outside walls are a true 6" wall with blown in Rockwool insulation and radiant barrier on the outside under the metal siding. I can build a metal building, not wood so I liked it. By doing it ourselves, we were probably 30-40% cheaper than wood.

Our home is very energy efficient. Our highest electric bill being $240 for an all electric home was not bad. It is approximately 1800 sq. ft under the roof with 2 small children where we wash and dry clothes daily.

It's also engineered for 120mph winds. We decided on this to be unique, and the only home in our county like this. Since we built, there has been at least 20 metal framed homes come up.

I've done quite a bit of research into straw bale homes in the last 5 years..We have quite a few in Missouri..humid, disgustingly humid area..the key to any building is to know your materials..a wider , higher foundation and a roof with a good overhang is the key to straw bale use. Straw bales need to be kept dry while building..just like piles of lumber..warped lumber is useless and so are soaked bales of straw.

I'd prefer to have the wall thickness and "give" of straw in a major earthquake event vs stick construction..same with fire..same with the savings for heating and cooling..IMHO, the list of benefits far outweighs any potential negatives.

Straw and wood have been on this planet for eons. Indian structures of adobe that are 2000 years old are still standing. Termites, fungi, and more are God's answer to cellulose. Focus upon cellulose heavy materials, and you will attract them all. I love the community spirit and self sufficient nature of those who do strawbale. I am just not wanting to take that cellulose laden path.

I think Keithb has a good solution using metal. However, I do see some complications. The first one is that metal conducts heat extremely well. Using metal 2x4's will lose half of the insulative value. I think the blown in rock wool is an excellent choice. I am also curious about how the inside walls are attached to the outside walls. How thick is the rock wool? How thick are the support beams?

Through history, many have used straw or similar plants as building materials. The fact that balers are fairly new, does not eliminate all of the historic efforts to use it as a building material. How long will it take to evaluate whether straw bales will survive throughout time? Since that is an unknown, I choose the safer path.

gobug,

First keep in mind, that I work for an Electric Coop that strives for energy efficiency throughout, and also in South Texas. This was the biggest selling point for us purchasing this type of home outside of us being able to put it up ourselves and save money there. The outside walls are a TRUE 6" wall which allows for typical R19 insulation. When you add the foil insulation as the housewrap, it's essentially a R30 value on the exterior walls plus the reflective barrier on the steel siding. Also keep in mind the 2x6 studs are actually 6" and not a complete stud and merely a C. This allows for more of the rockwool to allow for more insulation.

The interior walls are installed similar to the wood frame construction. A 6" was flat against the interior and the interior 2x4 stud butted up to it to look like a T.

The siding has a reflective barrier as well. The only true penetration is the sheet metal roof, but there is a foil reflective barrier under that as well. On our ceiling, I mounted angle irons to the purlin ceiling to extend that to 10". We blew rockwool in the exterior walls 6", and blew rockwool into the attic which was approximately 10" and an R38 value.

The framing is 3 sets of maybe 6x6 I-beam construction uprights that I believe were 20# / ft. It literally took 2-3 of us to stand them up, or my lift on the tractor. That then tied to an I-beam bolted to another that spanned across the house. There were three of these, then 2 lighter frames on the outside edges. Here's a link to a similar company that sells the same home we purchased: http://www.kodiaksteelhomes.com/planning/sequence.html The nice thing about these metal buildings/homes is they are engineered for 120mph and also designed for snow, etc. due to their high pitch roofs.

We sealed under each stud track, duct taped each seam of the foil insulation and the insulation company foamed around all entry ways and windows. We also installed a Trane 18 SEER 2-compressor variable speed heat pump.

It is a different process than traditional wood framing since there are no load bearing walls. We dried the exterior in and could look all the way across the home. We then started putting in our exterior walls. This allowed us to move walls during the building process, except around baths and toilets. We built on a cement slab so we were limited there.

Our attic in the summer is cooler than any other I've worked in. The roof is a continuous ridge vent, and the soffits are vented throughout.

I could go on for hours on this. Our local newspaper came out and did a front-page story of their lifestyle section on us building our house. We both were working full-time and I was attending the Univ. of Houston at night finishing up an Under-grad degree. On top of that, we were planning our wedding. We started in Feb. of 2001 and I moved in the Wednesday before our wedding in September.

That's interesting because I've had several bales of grain straw sitting in my barn unprotected for months and there isn't a single bit of evidence that bugs have been anywhere close to it.

Here in Georgia, bugs are something you cannot escape and if they find food, without taking extraordinary measures, it's history.

This spring, we'll be finishing up our 16'x46' strawbale addition because of what we KNOW about grain straw. Most of the negatives stated in this thread about strawbale construction are false.

When done CORRECTLY:

They are fire resistant.
They DON'T provide a haven for bugs.(1" base coat and .5" finish coat outside)
They ARE cheaper. (here in GA, $15sqft as opposed to $85sqft low end & DIY friendly.)
They DON'T require ongoing effort to keep dry. (measures are taken during construction only)
They DO last longer than buildings constructed of 2x4's, plywood and sheetrock. (They are far more structurally sound too.)

http://www.strawhomes.com/sban/tour/tour.html -Older strawbale homes.

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Dahc.

Just attended a seminar this weekend and one of the speakers was talking about strawbale houses. Also went on a tour of one in the area.
Starw is clean, no seeds and no nutritional value. Which means no/litttle bug problems. The stucco (sp?) also keeps out the rodents.
It was very amazing to learn. FOr example, hubby and I wanted to build with ICF but now I'm seriously thinking straw instead. Straw being R50 and ICF being a R22.

The gentleman with the strawhouse here said that the building codes were not hard to work around. He simply faxed the info/codes from California to the MD here. California has strict codes b/c of the natural forces wrecking havoc there. Our MD was quite alright with allowing it to be built along those standards.

Gave me the inspriation since one thing holding me back was worrying about passing codes.

When you say there is not a single bit of evidence of any damage, have you opened a bale and looked at it very carefully? Your environment has many insects, but only a small percentage of those eat cellulose, or habitate upon it. Is your garage the judge of how your house will stand through time?

Your stipulation "when done correctly" applies to every kind of construction. When done correctly, your home could be at the bottom of the ocean. I respect your effort to carefully investigate and proceed correctly if you do choose strawbale.

It seems to me that people in general tend to rationalize their current obsession. I'm included. I look for reasons to discount criticisms and encourage myself. I see that with those who love strawbale, earthships, etc. I see the structural design as more important than the specific material chosen for the construction. I have seen strawbale structures with excellent designs, and some which are just boxes.

No matter what choice is made for the materials, if done correctly, it requires a good focus, planning, effort, and care. Good luck.
Gary