Adobe, cob, etc. -- in engineered panels?

Hopefully the thread title is self-explanatory.

Wondering if anyone makes engineered panels of natural* earthen construction?

And if so, where can I get more info?

*I'm using "natural" in a strictly nominal way, to refer to construction methods and materials commonly bearing that marketing designation. I have wordier thoughts about the concept of "nature" and the terms derived from it, but those aren't relevant here.

What do you mean by, "engineered panels": A) something that can be made in one place then moved to a permanent location? B) something that can be moved regularly? C) something that can be tested in a lab to prove it has certain characteristics?

The closest thing that comes to mind is traditional wattle and daub walls in the British Isles. These were built in situ - infill between post and beam construction. I believe with regular maintenance and a really good hat (big roof overhangs) they lasted a long time.

If by engineered panels, you mean the kind that usually have styrofoam sandwiched between plywood, the closest thing would be clay slip straw walls I've read about, but they tend to be built on site and are thicker than the styofoam version. Again, if I recall correctly, the walls are "infill between post and beam" as opposed to "structural". This is likely because it would be difficult to be sure everyone building with this technique was doing it structurally well enough to be safe.

Lately I've been wondering what the lifespan of styrofoam is if it's sandwiched such that it is protected from sunlight. Most plastics seem to get brittle and turn to dust just from time, but if styrofoam is not exposed to sunlight, does it keep its R-value indefinitely? Or for 60 years - the average life expectancy of typical houses built now? I moved into a new house in the late 1980's but had to relocate shortly after, and I really wonder how it has faired. Has its plastic siding even lasted 35 years?  I would do everything to avoid a house like that today, but I had never heard of permaculture then, even though I was somewhat aware of the damage humans were doing to their environment by building houses without considering how long a house *could* last.  

I've worked with a local natural builder who makes SIPs with light straw. His preferred designs are timber frame with light straw infill, and he believes SIPs are a good way to speed up the process. Make them in advance, in controlled conditions that are optimised for density control and drying, and then when you install them they're ready for plastering right away.

Light straw or fiber adobe seem ideal for SIP.
Anything heavier like traditional cob or adobe seems like it would weigh to much.

I work with cob, adobe and feel that panel construction as it sounds is not the best method of application.
Panels need cranes, adobe can be done very effectively by hand and I think that is its advantage over SIP design.

This is a blossoming industry in natural building. EcoCocon is a leader in Europe, while numerous builders, such as New Frameworks are getting it going in North America. Straw insulated panels, sometimes sheathed in plywood for shear strength, but can be plastered instead for certain applications. Plastering a panel is cool because a thick 1 1/2” layer of plaster can be applied quickly when the panel is horizontal, then when dry enough the panel can be stored vertically.

It’s totally a thing, it works well. It’s just slow to get started. But its happening!

Are you talking about a stand up panel, filled with Adobe or a panel filled with straw or similar stood up and then coated with a earth plaster?
They are 2 different panels.

Making light straw clay panels that can be dried, then put up and plastered immediately, sounds like a good method. Any finished panels need to be strong enough to not crack in handling, and joints need to be precise or designed to be covered.

Thanks, everyone for your comments.

Thanks Scott Lawhead, for letting me know someone is indeed doing this. I will check those out.

This is a Frankenstein’s monster comment replying in one fell swoop to the whole thread up to this point.

What do I mean by “engineered panels”:

By “engineered panels” I mean something manufactured (probably all in one location) offsite to precise specs, then brought to the site for permanent assembly. I was not thinking of SIPs as the only example of this, but they are one example of this. Panels used as infill between framing members could be another example, even if each panel is one wythe of an insulated wall with the insulation provided separately.


Insulation:

I’ve asked on this very forum about insulating with styrofoam, and the consensus seemed to be that styrofoam can catch on fire and then release poisonous fumes, which is a showstopper for using it in houses, or in houses made out of insulated panels.

Like Jay Angler however, lately I too have wondered about using styrofoam as insulation—-but in a slab or basement floor. From an environmental standpoint it would be a most useful sequestering, I’d think.

Joinery:

I’m not familiar with how engineered panels are joined; I imagine many methods are possible, and it’s a matter of finding an optimal way of doing it given the materials, the form of the panels, and what skills, tools, and materials are available at the assembly site.


Panel composition:

I guess I was thinking about adobe/cob etc. more in terms of mixtures and qualities than in terms of what form they’re typically given. But it’s true, typical natural earthen walls are very thick, and thicker at the bottom than at the top. They probably weigh a million and a half pounds each. You can’t just stack up walls like that on a flatbed.

This maked me wonder, though, could you spread a layer of (e.g.) cob over a sandwich of materials that includes hardware cloth on the outside (to act like rebar), various control layers (vapor barrior, insulation, etc.) under that, and framing and insulation in the middle, to create a panel that, once dried/cured/etc., can be moved and installed somewhere else?

Would those still be prohibitively heavy? Too brittle? Could the brittleness be reduced by changing the mixture of ingredients?

I’ll have to check out Scott Lawhead’s examples to see how they pull it off.


Why I’m asking:

I’ve heard it said of construction: good, cheap, fast — pick 2.

I know that one set of reasons to build with adobe, cob, etc. has to do with the low barrier to entry, with all the cost being on the time & effort side. If you have the time and can make the effort, you get the material advantages of adobe/cob/etc. This is great if you value Good & Cheap but don’t care about Fast.

But what if instead you are more interested in the qualities of earthen materials, and you don’t mind renting a crane in exchange for the advantage of a relatively fast and easy assembly? Or from the producer end, what if you want to offer a competitive natural alternative to people who might otherwise go with SIPs or conventional construction? You are interested in Good & Fast, and Cheap is less of a concern. (Again, it’s cool to know someone is doing this.)

Alternatively, maybe it would be possible to make a bunch of your own panels in one place, and then transport them to another place in instances/locations where building walls the traditional way would be more difficult?

Ned,

What would you gain by having a panel covered with thin cob? Cob is heavy, cheap if collected on-site and works as thermal mass if applied thickly.
If the panel had a brittle minimum of 5 cm of cob on each side and let's say it would be 1x1 m then already it would weigh around 200 kg (440 lbs). Some machinery would be needed to lift and install within already preconstructed frame.

I think one of the biggest struggles with adobe/cob pre-manufactured panels is (as has been mentioned) the weight.

Do the panels have to be adobe/cob? I would think that solid wood, with a more natural insulation like hemp wool, or sheeps wool, or mycelium could provide much, if not the same, benefits. I would personally even be ok with mineral wool or cellulose in many cases.

Matt McSpadden wrote: I would think that solid wood, with a more natural insulation like hemp wool, or sheeps wool, or mycelium could provide much, if not the same, benefits. I would personally even be ok with mineral wool or cellulose in many cases.

To me the key thing is to have a good insulator on the outside, then thermal mass in the house.

It seems to me that Cob and Adobe are both insulation and thermal mass combined. That works in many ecosystems, and when done right and maintained, can last over 200 years, but it takes time and is very heavy.

Wood panels with wool/mycelium insulation, will provide excellent insulation between either cold or hot outdoor temperatures. (People need to pay more attention to keeping heat out of houses in the sorts of heat waves we've been getting in many places in the last decade.) Once that envelope is built, temperatures will be more comfortable inside if there's thermal mass to moderate swings from whatever heat source is being used.

My house has essentially no insulated thermal mass. At this time of year, if the clouds agree to leave for a bit, the sun's low angle shines in the living room window and the room temperature can rise from ~62F up to 70F or higher. However, as soon as the sun sinks below the tree line to the west, the room starts to cool off quickly.

My sister's house has lots of thermal mass (breeze blocks with bricks on the outside), but absolutely no wall insulation. (built in the late 50's when energy was cheap and plentiful). The mass does slow the swing of temperatures in the house, but the lack of insulation between the block layer and the brick layer is quite obvious. If she doesn't leave her coat closet door ajar, the wall will get ice on the inside! Unfortunately, fixing this would be very pricy. Most people who've upgraded these old houses have changed the bathrooms and kitchens, but done nothing about the underlying heat/cool cycle for that reason.

So finding a way to make some kind of affordable panel that can pass inspections and is mostly natural materials, such as the mycelium mentioned above, would be a huge improvement in housing. But to make the house more comfortable, I think having some interior walls of brick/stone/cob would be a big improvement over the panels alone.

The living room I mentioned above, has a 10' wall shared with the kitchen. If that wall was thermal mass, I think it would make a noticeable difference.

Jay Angler wrote:
.. It seems to me that Cob and Adobe are both insulation and thermal mass combined...  

Very true. I had forgotten about the thermal mass portion, and was thinking just along the lines of structure and insulation and breathability.

I have wanted to play with it for building retaining walls.  But actually having done it not yet.  My test brick has done 4 years out in the weather and still looks good but that is all the farther I have gone.

As for panels no but large bricks there is a you tube video on a machine that makes large cob bricks that interlock sort of like Legos  From the video they are roughly 1 foot x 1 foot x 2 feet.  The argument for them was how hard they were pressed together supposedly making then very durable

SIPS are a decent building idea. As a framer I don't care much for their inflexibility of design. Big rigid rectangles, sized like plywood. Foam core bonded permanently to OSB, chipboard type ply.
Not nearly as eco/permie friendly as locally produced wattle and cob/daub. Some consideration must be given to off gassing of manufactured components, although that has been mitigated in recent years by production changes.
They spline together with standard framing lumber and 8d nails. Very fast. Great insulating value. Air tight. Shear rigidity, built in.
If you don't plan on lighting your house on fire, then don't confine your mind to the terror of toxic gasses. Make sure your electrical is up to snuff. Have enough water to handle your own situation until help arrives. If your house is burning, you have bigger problems. Stand up wind to watch the flames.
Like wise, don't confine your mind to the idea of needing a crane. 4x8 ft SIPS 6 in thick weighs less than 100lbs. That's a lot of wall. I've handled SIPS, alone, almost 12 ft long.
DryVit was a light, semi-flexible, stucco like plaster with some insulating qualities we used in Montana back in the 80's. Had some perlite in it, believe. The old stagecoach inn in West Yellowstone I helped build as a framer '88 or so has a bunch on the outside. Still there. The idea has been there forever, I'm sure you could do just as well now on your own jobsite. But you will give up some of the more permie aspects of cob, my guess.
Prefinishing stand alone panels would work, but you'd have a permanent joint and it's possible drawbacks to deal with. The panels referenced above are more likely to be infill in a timber frame type setup.

Cristobal Cristo wrote:Ned,

What would you gain by having a panel covered with thin cob? Cob is heavy, cheap if collected on-site and works as thermal mass if applied thickly.
If the panel had a brittle minimum of 5 cm of cob on each side and let's say it would be 1x1 m then already it would weigh around 200 kg (440 lbs). Some machinery would be needed to lift and install within already preconstructed frame.

I guess I was imagining it as an alternative to drywall. But yeah, it would still be way heavier.

C. Letellier wrote:I have wanted to play with it for building retaining walls.  But actually having done it not yet.  My test brick has done 4 years out in the weather and still looks good but that is all the farther I have gone.

As for panels no but large bricks there is a you tube video on a machine that makes large cob bricks that interlock sort of like Legos  From the video they are roughly 1 foot x 1 foot x 2 feet.  The argument for them was how hard they were pressed together supposedly making then very durable

Pressing cob/adobe into lego-like bricks is another idea I've heard a little about and want to learn more. Do they need mortar between them? Do you dry them first, or stack them wet? Presumably they are stacked offset; what about half-bricks at the ends of courses? What about over windows and doorways? Do you use metal lintels?