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Alternative Timber Frame Enclosure methods

Started by S.Hyland, April 13, 2013, 02:04:19 PM

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S.Hyland

Hi All,
  It's been on my agenda for the last year or so to start working on a plan to enclose my frames with more natural methods. So far I have been making my own insulated panels (typical SIP construction). This has worked out pretty well and has proved to be a straightforward and cost effective way to go. However I'm still not too hot on EPS, urethane adhesives, and osb /plywood.
  I'm currently leaning toward clay based slip straw/ slip chip methods or rammed earth. I'm kind of biased against straw bale, not because of any terribly informed reason, they just make me nervous because of moisture, vermin, mold, and allergy concerns. But I really don't have enough firsthand knowledge to support that bias. I'm working on finding people in my area that I can talk to who do this work, and doing my own reading and research. 
I would love to hear experiences and recommendations from all you fine folks. Thanks in advance!
"It may be that when we no longer know which way to go that we have come to our real journey. The mind that is not baffled is not employed. The impeded stream is the one that sings."
― Wendell Berry

canopy

The book "econest" is all about timber frames with walls made of straw coated in clay which is also known as leichtlehm as it originated in Germany. The particular approach of book is to wrap the walls around the outside of the frame. They use a clay plaster finish unless there is heavy rain or snow drifting in which case they use wood siding on the outside.  You need long roof overhangs for this type of wall. It's a good starter book to understand the approach and see examples of the appearance rather than a thorough how-to guide. They also have workshops.

I have experience with this type of wall system and like its natural characteristics and high insulative value. However it is an extraordinary amount of back breaking work mixing and setting the walls if doing it yourself. There are just so many cubic yards of material that needs moved and mixed and you get real muddy in the process. Then you need base coating and finish coating which is a whole other learning process and lots of work. Having lots of help and/or machinery is just about a must for a structure of any size.

S.Hyland

The rammed earth approach especially seems appealing. One could use rammed earth for the walls with timber framed 2nd floor framing and roof framing. I wonder how rammed earth would fare under building code in NY? I imagine that the requisite R values would not be present. Of course code wouldn't take into account the other advantages (thermal mass, breathability, etc.).
  The other aspect that intrigues me would be the possibility of making it possible to accomplish relatively low cost. My area is pretty rural and destitute, but I really want to be able to provide quality housing to people who otherwise wouldn't. The biggest cost with something like rammed earth seems to be how labor intensive it is. If one experienced person was on site to supervise and provide forms and tools, the homeowner could put together capable volunteer labor. The timber framing cost would be reduced considerably if it consisted only of roof and floor framing. In theory, an affordable top notch house? 
  Of course, I haven't gotten into the details yet. I'll have to talk to some people who have the experience and find out what my local resources might be for both rammed earth and clay/ woodchip infill.
  Has anyone on the forum done any work on this spectrum?
 
"It may be that when we no longer know which way to go that we have come to our real journey. The mind that is not baffled is not employed. The impeded stream is the one that sings."
― Wendell Berry

S.Hyland

Hi Canopy,
I'll check out that book, it's been mentioned in other places as well. I think in my area I might be more inclined to try the woodchip/ clay variant. Just because there are quite a lot of sawmills in the area, and woodchips and sawdust would be extremely  easy and cheap to source. The soil in my area is also predominately clay. What kinds of clay are considered suitable or not suitable?
  I'll definitely have to find some people that are fairly close to me who would let me see some work firsthand. Which may be a bit difficult, since everyone that I know of doing alternative enclosures around here seems to gravitate toward strawbale. I'm not quite sure why, it may have something to do with being a bit more known and accepted by code enforcement.
"It may be that when we no longer know which way to go that we have come to our real journey. The mind that is not baffled is not employed. The impeded stream is the one that sings."
― Wendell Berry

ziggy

Rammed earth provides nothing in the way of insulation, and is doubtful suitable for your climate. (I built a similarly massive house, a cob structure, here in northern MO, so I have experience with ill-equipped and massive houses in northern climates. My advice = don't do it. Not if you want to be able to live in it comfortably year-round.)

Straw bale is more insulative that light clay straw, but it requires more forethought in the design process. (Really, both methods would benefit greatly from a lot of forethought, but anyway...)

I'm a bit biased towards straw bale, as I am building a timber frame/straw bale house as we speak. I have few concerns about vermin (we're up off the ground on piers anyway), but moisture is of course a valid concern. It's more of a concern during the construction phase -- keeping your bales dry in storage, and then ensuring that the tops of the bales are not exposed to a soaking rain when your walls are going up.

Working with any type of natural material means labor. That is a given, whether it's rammed earth, straw bale, and light clay straw. Straw bale and light clay straw are both fairly labor-intensive to finish with plaster, and it is an essential detail to get right. After all, you don't want to re-apply your plaster after only a few years.

There are huge benefits to building with bales -- longevity, fantastic insulation, nice thick walls (aesthetically pleasing, great for carving niches and making rounded window reveals), lovely sound dampening, and relatively easy to maintain.

With whatever natural method you choose, I cannot recommend enough that you practice on some one else's project first, preferably locally (material availability and soil types, specifically clay for earthen plaster varies wildly across the country)... volunteer, attend a workshop, etc.

(Check out my website for more about SB and timber framing... I actually just happened to write a post on this recently.)

D L Bahler

I have been developing a system for some time, an idea that uses the notions of the light clay wall system, but makes it in a form that is easier to install and more insulating
what I have come up with is a system using clay and 'mineralized wood'. my method of mineralizing wood is to put it in a kiln and burn out the sugars and tars. in other word, I make charcoal.

this charcoal is mixed with clay -actually loam, not straight clay- and then formed into bricks. these bricks are dried beforehand, and are lightweight
charcoal is an excellent insulator, and the loam makes it fireproof. I haven't done any tests to determine r value, but expect that it would perform fairly well 

losttheplot

The Canadian Mortgage and housing corporation did a study on straw bale a while back.

http://www.cmhc-schl.gc.ca/en/inpr/bude/heho/heho_004.cfm

I am not saying its good or bad .
DON'T BELIEVE EVERYTHING YOU THINK !

zelpatsmot

Larsen truss system with blown in recycled cellulose, or perhaps a natural sheep wool product?

Jay C. White Cloud

https://www.youtube.com/watch?v=iSApSrd8VwY

https://www.youtube.com/watch?v=RTJLI3r-res

https://www.youtube.com/watch?v=E3371TIAA1E

https://www.youtube.com/watch?v=PWyEMVhDwmg

You can find more like them.

SB is good, but I think this system is probably better, over all, in application, durability and labor to application ratio.

I believe, other than modern foams, which are very efficient (but expensive,) this is probably the system to measure off of, for nonstructural thermal envelopes.
"To posses an open mind, is to hold a key to many doors, and the ability to created doors where there were none before."

"When it is all said and done, they will have said they did it themselves."-teams response under a good leader.

S.Hyland

Ziggy, If I did rammed earth in this area I would want to work some foam into the wall. Probably reclaimed polyiso. A couple of years ago a got several hundred sheets of 4" polyiso from a local school roof for $5 a piece! It's almost gone now, but that was nice. I think if I cultivate a few contacts a bit I could get more. I'll check out your site, I definitely need to see and try some things firsthand.

That sounds like an interesting system DL Bahler. I imagine that another added benefit of using charcoal, is that it would be a more stable, rot proof material than either wood chips or straw.  I have access to lots and lots of junk wood in my area. Do you have any pictures of the block that you have made? I would love to hear more.

Thanks for the videos Jay. I guess I just need to build some test walls and try a few things. I've seen a couple of times where you have expressed a dislike for EPS as opposed to polyiso. What specifically don't you like about EPS? I was under the impression that EPS used a less harmful blowing agent, and was a less toxic product in composition. I have been using quite a bit of new EPS for panels, although I am getting away from the typical Osb/foam/Osb. I want to start making them with 5ply 1/2" plywood as the exterior layer, foam, and MGO as the interior. That would bring the cost up a bit, but not that dramatically.
I figure that the panels will always have a place in what I am doing, but I need to widen my options for people.
"It may be that when we no longer know which way to go that we have come to our real journey. The mind that is not baffled is not employed. The impeded stream is the one that sings."
― Wendell Berry

Jay C. White Cloud

Hey Sean,

EPS (expanded polystyrene insulation) was (is) used as a bending, and nesting medium for carpenter ants in labs as well as several other organisms;  Mice, Rates, and other rodentia will burrow through it with ease.  Even with the "treatment" that some of these get, the infestation happen very rapidly. 

Urethanes in general (like polyiso) are more durable, and much less likely to harbor these issues.  Plus the R factor is much higher.  I would prefer to use "straw clay" first, then cellulose if possible, but urethanes are hard to beat speed wise on a contract or spec build.  That is why I have moved away from panels completely except on roofs, and use a wall truss system.  It accommodates the other aspects (i.e. wiring, plumbing, mechanicals of other types, and future alterations just to name a few) of a build so much better.  Panels do one thing really well insulated, but they don't make these other jobs very easy.

Hope that helps.
"To posses an open mind, is to hold a key to many doors, and the ability to created doors where there were none before."

"When it is all said and done, they will have said they did it themselves."-teams response under a good leader.

ziggy

Factory seconds polyiso can be purchased here: http://insulationfactoryseconds.com/?gclid=CLLA9pyA1rACFUMCQAodrl-D1A

Great prices, and up to 4" thick sheets!

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