Green Building Discussion

 

Topic: Alternatives to Foam Panel Systems

Discussion Participants:

• Chris asks how to cover a timber frame without foam
• Marc Rosenbaum offers 2 choices
• Bruce Sullivan suggests bales of straw
• Bill Christensen likes a clay system
• Terry Brennan fills in some other ideas
• Buzz Burrell has some trouble with light clay
• Marc Rosenbaum with more on the clay system
• Marilyn wonders what a "Cob Folk" is
• David Kibbey fills us in
• Buzz Burrell brings up some other systems
• Alex Wilson is looking for a new cement
• Bill Christensen has more on Cob Builders
• Bill Christensen asks about India
• Marc Rosenbaum on light concrete
• Buzz Burrell on Pumice-Crete

All postings are the opinion of the writer, and BuildingGreen can take no responsibility for their accuracy or appropriateness.

Chris asks how to cover a timber frame without foam

From: MFigs@aol.com
Sent: Wednesday, November 27, 1996 11:55 PM

I went to a local Timberframe Show and was dissappointed to find that ALL the companies there use some sort of foam/board/skin/panels to enclose/insulate their beautiful handmade timberframes.

What are some green/non-toxic alternatives to enclosing the house? I prefer not to use foams or plastics. I hear wool can be quite toxic if it burns.

I'm hearing talk about insulated blocks. They sound toxic. Thanks for suggestions Chris

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Marc Rosenbaum offers 2 choices

From: Marc J. Rosenbaum
Sent: Thursday, November 28, 1996 8:14 AM

Two alternatives are Larsen trusses filled with the insulation of your choice, and straw-clay as practiced by Robert Laporte (505 471-5314) , which likely has a lower R value.

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Bruce Sullivan suggests bales of straw

From: Bruce Sullivan
Sent: Thursday, November 28, 1996 3:40 PM

One alternative is to fill in between the timber frame with straw bales. The Solstice Web site (run by CREST) has information about strawbales including the archives of the Straw Bale discussion group. You'll find the archives of that list at:

http://solstice.crest.org/efficiency/strawbale-list-archive/index.html

Bruce Bruce Sullivan Tel: 541-484-9353 Iris Communications, Inc. Fax: 541-484-1645 Web: http://oikos.com/ E-mail: iris@oikos.com
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Bill Christensen likes a clay system

From: greenbuilding Conference @ txinfinet.com
Sent: Thursday, November 28, 1996 11:19 PM

I had also noticed this, and was disappointed by the trend.

I recently have been in touch again with Robert LaPorte, a timberframer who uses leichclem as infill. Leichlclem is german for light clay, a technique of coating straw with a clay soup and packing it into slip forms clamped onto the timber frame. The result is a smooth, insulating, breatheable thermal mass that can then be finished with plaster. The technique has been used for centuries in one form or other, and Robert told me he took part in a renovation of a ~700 year old structure in Europe that had leichclem, and when they broke into the wall to add a door, the clay-encased straw was in perfect shape, as if it had been harvested yesterday.

This combination is, at present, the method I would use if I were to build myself a new home.

Robert runs (or maybe is..) the Natural House Building Center, 2300 W Alameda A5, Santa Fe, NM, 87501 (505) 471-5314

I certainly hope there are some other people out there using other green/nontox methods. I'd love to hear of them.

Bill Christensen billc@txinfinet.com Sustainable Building Calendar at http://www.greenbuilder.com
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Terry Brennan fills in some other ideas

From: TBren46501@aol.com
Sent: Friday, November 29, 1996 10:37 AM

Hi Chris,

Years ago, before sandwich panels, I built an entire 2x6 wall on the outside of the heavey timber and insulated it with fiberglass or cellulose or I layered up foam and nailers on the outside. A whole exterior wall on the outside uses way to much framing material. Layering up my own faom sandwich uses more lumber than factory made panels and doesn't avoid thermoplastics. Insulated blocks would also be a redundant structural system. I recall years ago seeing an article on ceramic based panels made in Japan. The r-values were not impressive, but ceramics is an amazing material. I bet Alex Wilson or Nadav are more current than I am. They post regularly on this list.

In terms of toxicity, I've found cellulose and fiberglass to be at the heart of more health related complaints than foam. Both paper dust and glass fibers can cause irritation of the skin, eyes, nose and throat. Some people have allergic responses to newprint exposure (I believe this is largely due to compounds that outgas from the inks) making them susceptible to cellulose exposure (e.g. the house runs negative or return air in wall cavities draws outdoor air into the house through cellulose insulation - mostly a problem in attics where the cellulose can't be dense packed). The most likely reaction to plastics these would be chemical sensitization to isocyanates. My experience is this is usually an occupational illness, that is people who install the stuff and get very large exposures. However, some fraction of us are sensitive to much lower exposures than the bulk of us. So I am in agreement with the general rule of eliminate or reduce toxicity, volatility, irritancy and potential for accidental exposure to concentrated materials. Good luck in your search and let me know how you make out.

Terry Brennan
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Buzz Burrell has some trouble with light clay

From: Buzz Burrell
Sent: Monday, December 02, 1996 10:05 AM

A caveat - Two of my friends raved so much about Robert LaPorte, I took one of his 3-day workshops about 2 years ago. With great will power, I lasted one day - he was the most obtuse, egomaniacal person I've ever met; conversations with Jehova's Witness's on my doorstep have been engaging and pleasant by comparison. Some us walked out the first day, while others considered him God's gift to the building industry; reactions to the workshop were quite varied.

Regarding the method itself, my opinion is that light clay does produce a wonderfull result; the combination of straw and clay is quite natural, logical, and synergistic. However, the only drawback is a big one: the process is incredibly labor intensive. I was stunned by how many times the material required vigorous manual manipulation. Shortly afterward I went to India where I investigated various natural building methods in a country that prides itself on low-capital home-grown technologies. Turns out, they do not use this method either. So if strawclay is too labor intensive for India, I would recommend us white folks do a practice wall first before committing to this building system.

As an anecdotal comment, after 2 years, neither of my friends have finished building their light clay houses. These projects have been debacles. One person is still rotating housesitting, and the other will be spending her second winter in a trailer. Thus, the Robert LaPorte program triggers for me some larger issues - Regarding shelter, I am a believer in returning "power to the people" (for those who want it); just as we need to take responsibility for our own health, the choice to participate and understand fully the creation of one's own shelter seems like a fundemental human right that has been lost in today's building industry. However, the "Build Your Own House For $99.95!" workshops may create an unrealistic expectation that may hinder rather than help the movement.

There exists in the US building industry a huge spectrum of processes; from 1,000 tract homes per year corporations, to people teaching others how to literally handcraft a house. This breadth doesn't need to be critisized, we are all different, and so there is something for everyone. But to me anyway, both ends of the spectrum contain equal amounts of misinformation and strangeness, and suggest equal amounts of caution.

I very much appreciate the quality of dialog on this List! I thank everyone for their input.

Buzz Burrell Geneva Development Corporation Boulder, CO
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Marc Rosenbaum with more on the clay system

From: Marc J. Rosenbaum
Sent: Monday, December 02, 1996 6:02 PM

Hello Buzz -

I took one of Robert's workshops, and I would not describe him as obtuse. He is very committed to what he teaches, an evangelist really. I had some tough questions for him, being a nerd, about insulation values and quantities of materials and time involved. He was willing to say, I don't know, occasionally, which always endears a person to me, and he was open-hearted about being challenged in front of a largely lay audience who would believe almost anything! He was a capable teacher and certainly knew his stuff about his system.

I found myself falling in love with the look of straw-clay. This past year I attempted to do straw-clay on a very small addition (8x12) and was unsuccessful due to the quality of the local clay which i had gathered - it wasn't sticky enough. I called Robert and he recommended supplementing with ball clay. I tried that, it worked great, but I decided that importing several hundred pounds of clay (according to my calcs) was less sustainable than doing the walls out of pine boards, drywall and cellulose.

There are many paths, as you have noted, and the answer I have for myself which i offer to you about the labor intensity of straw-clay and other similar systems is that if we built only what we needed (very small) then we would have time to hand-craft our dwellings out of more natural materials (and R value would be less important, if the wall area is very small). I think this is behind the work of the cob folks out in Oregon. So, not for everyone, but maybe for some.

Marc
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Marilyn wonders what a "Cob Folk" is

From: marilynz@mail.westonia.com
Sent: Monday, December 02, 1996 4:29 PM

Phooey! I don't know anything (yet)!

What "cob folks in Oregon"??

What are "cob folks"??

Marilyn

Thank you!
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David Kibbey fills us in

From: IAQKibbey@aol.com
Sent: Monday, December 02, 1996 10:03 PM

Cob Cottage Company Director: Michael Smith P.O. Box 123 Cottage Grove, OR 97424 541-942-2005

Owner : Ianto Evans same address 541-942-3021, Fax or phone

Cob building employs earthbuilding techniques with straw and clay to build natural "breathing walls" based on centuries-old techniques from Wales and Europe. Many hybrid structure types have developed from this and other earth-building tecniques. Ianto Evans and Cob Cottage Company give workshops, sharing their experience in many locations around North America. Several others associated with Cob Cottage Company or other Oregon cob building operations ("Cob Folks") who recently attended the Natural Building Colloquium at Shenoa Retreat Center in Northern CA are: Becky Bee, 541-471-3470 Janine Bjornson, 541-942-2005 Robert Bolman, 541-344-7196 Shannon Dealy, 541-451-5177 or 800-467-5820 (she set up the Cob Cottage Co. Website and list server and has taken courses there) Sorry, I don't have the web site address. Kiko Denzer, kdenzer@mcimail.com, 541-438-4300 Erick Hoel, 503-589-2077 Mark Lamberth, 541-345-9541 Linda Smiley, 541-942-2005, fax 541-3021

These people love to build with soft mushy material they have mixed with their bare feet--earthy types who have a lot of fun building with Mother Nature. check 'm out!

David Kibbey
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Buzz Burrell brings up some other systems

From: Buzz Burrell
Sent: Tuesday, December 03, 1996 12:07 PM

Thanks for your comments; since he is a well-regarded person, I am glad to know Robert LaPorte exhibits much better behavior than I experienced. I guess he had a bad day 2 years ago - maybe like I was must have been having when I went out on a limb and described my negative experiences in a public forum.

>There are many paths, as you have noted, and the answer I have for myself which >i offer to you about the labor intensity of straw-clay and other similar >systems is that if we built only what we needed (very small) then we would have >time to hand-craft our dwellings out of more natural materials (and R value >would be less important, if the wall area is very small). I think this is >behind the work of the cob folks out in Oregon. So, not for everyone, but >maybe for some.

Well said! And besides the ecological aspects, there is the *satisfaction* factor - rather than supervising the building of a trophy house, I've always thought it would be really nice to handbuild a house out of rock, spending whatever time as it took. Just the thought of carefully examining each and every rock sounds wonderfull to me.

Bill C also responded:

>It (strawclay) still sounds better to me than making adobe bricks or rammed earth. But I >haven't done the hands-on with them yet either.

Actually, I was considering them both when I took that fabled workshop. One hour of gathering, shoveling, sifting, sorting, mixing, rolling, carrying, placing, and then beating on strawclay convinced me to use a Compressed Earth Block system. I thought I wanted to do the cheapest system possible, but I instantly decided to spend some money instead (with clear feedback from my body).

C.E.B. is sometimes just called Rammed Earth, and sometimes called Adobe, in order to avoid lengthy explanations and because they are very similar. Quick clarification:

Adobe - Sun dried mud. Famous, very common in SW, very historical. Blocks can be any size, but are commonly 10" x 14" x 3.5". and are stacked with a mud motar. Nowadays are often made with 4 - 10% asphalt for stabilization (weather resistance).

Rammed Earth - Like it sounds: compressing dirt under pressure into a structural form. Rammed Earth usually refers to a monolithic wall form, like a concrete pour, into which earth is tamped either by hand or with a hydraulic ram. Earth used is damp, never wet (amoung other differences from adobe).

CEB - Great pressure is used to compress earth into blocks. Thus, it like using Rammed Earth methods to create an Adobe block. Many sizes, but 8" x 12" x 4" is most common. Does not require motar joints. Another cool thing is you can (if the soil is right) excavate your foundation, and then use that same soil to build your walls! (Quantities used can be the same). Overseas (see below) people use lever-action presses, while in the states, people rent powerfull hydralic presses.

Disadvantage is same as adobe: unlike strawclay, there is minimal insulation. Advantage: my walls (including bond beam) were done in 12 working days.

>>Shortly afterward I (Buzz) >>went to India where I investigated various natural building methods in a >>country that prides itself on low-capital home-grown technologies.

>I'd (Bill) be interested in hearing what you felt were the most exportable building >methods over there. (I doubt many americans will want to build dung huts, >for instance). It seemed to me that the majority of the buildings that I saw >were brick masonry with plaster (this was in the New Delhi area)

Quite right. Brick and concrete is everywhere (as in about 90% of the world, wood is never a primary material).

What I found was Compressed Earth Block being tested in all parts of the country. I never heard mentioned strawbale or strawclay; adobe is rare but still being used in some remote locations. I found CEB machines made in France, California, and Australia in use, and now they are manufacturing one specifically for village use in India.

You may have heard of a company called Development Alternatives; based in Delhi, it is the most advanced alt-tech organization I've ever encountered, the RMI of India if you will. Additionally, the real international earth-building experts are the French; CRATerre has built amazing projects all over the world (except in NA).

CEB works great in India because it isn't all that cold, so insulation is less a requirement, and the comfort standards are broader. They just render the walls with a wetter version of the same earth mix, and then either do a earth, concrete, or tile floor, and the same for the roof. Seeing a CEB roof is quite impressive; reminded me how very little I know about building.

Take Care!

Buzz Burrell Geneva Development Corporation Boulder, CO
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Alex Wilson is looking for a new cement

From: Alex Wilson
Sent: Monday, December 02, 1996 5:42 PM

I have long believed that one of the most significant product developments waiting to happen in the building field is a foamed cementitious or mineral-based insulation that 1) has good insulation value, 2) has good structural properties, and 3) is light-weight. Air Krete is a foamed inorganic cement, but it has very poor structural properties. There are companies working on this holy grail, but nothing has yet emerged that I am aware of. I have a sample of some very interesting foamed silica "beads" that can supposedly be aggregated like styrene beads into boardstock. The company has not yet gone that far, but such developments could be right around the corner. When that product arrives, it could be just what we need for foam-core panels for insulating timber frames and (for the wood-efficient among us) structural insulated panels. Anyone know of any such developments out there?

Alex Wilson Environmental Building News
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Bill Christensen has more on Cob Builders

From: greenbuilding Conference @ txinfinet.com
Sent: Monday, December 02, 1996 10:01 PM

Cob is a method of building with straw and clay. It's more clay than straw, and is mixed near the site and formed into "loaves" and often passed, bucket brigade style, to the building itself and molded into walls.

The "cob folks" referred to are most likely the Cob Cottage Company (you can find out more about them at http://www.deatech.com/cobcottage/). They've also started a Cob Building Listserv, if you're really dedicated. There's info about it on their website.

Cob is a rather labor intensive method. Perhaps partially as a result of the labor necessary, many cob buildings being built in the US at this time range from "cozy" to tiny, though it has been used for "full size" buildings for a long time in parts of England. One plus is that it's easy to do non-rectilinear shapes.

Bill Christensen billc@txinfinet.com Sustainable Building Calendar at http://www.greenbuilder.com
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Bill Christensen asks about India

From: greenbuilding Conference @ txinfinet.com
Sent: Monday, December 02, 1996 10:01 PM

Heh heh. Well, not having taken a workshop from him yet, I can't say for sure. But i do know he is rather... shall we say, "determined". Thanks for the alert, i'll take it in stride.

It still sounds better to me than making adobe bricks or rammed earth. But I haven't done the hands-on with them yet either.

>Shortly afterward I >went to India where I investigated various natural building methods in a >country that prides itself on low-capital home-grown technologies.

I'd be interested in hearing what you felt were the most exportable building methods over there. (I doubt many americans will want to build dung huts, for instance). It seemed to me that the majority of the buildings that I saw were brick masonry with plaster (this was in the New Delhi area) (NOTE: This discussion is continued under the heading "Building With Earth".)

Bill Christensen billc@txinfinet.com Sustainable Building Calendar at http://www.greenbuilder.com
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Marc Rosenbaum on light concrete

From: Marc Rosenbaum
Sent: Tuesday, December 03, 1996 7:40 AM

I agree with Alex that there are many reasons why this would be a "dream material". Closest thing yet is autoclaved aerated concrete a la Hebel, but density is too high (~30 pcf) and R value is too low (~1.2/inch). In fact, aac is similar to wood in both numbers! The strength of the material is adequate although not outstanding, and it makes me wonder how a material which weighs, say, 1/5 as much will have significant structural ability. But obviously EPS works in structural panels, so I'll be an optimist.
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Buzz Burrell on Pumice-Crete

From: Buzz Burrell
Sent: Tuesday, December 03, 1996 12:07 PM

any >such developments out there?

Unfortunately, no (I'd certainly be interested). But, there is Pumice-Crete.

Pumice-Crete is a combination insulative and structural material at the same time. It is used as an entire wall system, not as infill.

Pumice, a porous volcanic rock, is substituted for all the aggregate in a concrete mix, and then the amount of cement is greatly reduced. Instead of 3000 psi compressive, it is around 400 psi - but with an R 1.5 or 2 per inch. But it should perform well above that, because there is no degradation, no air leaks, no gaps, and with integral thermal mass.

Scott MacHardy in NM is THE man for this - http://www.taosnet.com/pumice-crete/index.html

We're scheduled to break ground on a pumice-crete house here in February. In another year, I'm sure I'll know a lot more!

Buzz Burrell Boulder, CO

PS: I can't resist repeating here my daily building mantra: "As soon as we're done, we'll know how to do it".