Ned Harr

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?

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.

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?

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.

Daphne Rose wrote:Since most young people can’t afford land anymore* it’s waaay harder for us to get into permaculture.

To me the term "permaculture" has never necessarily meant "fully self-sustaining off-grid homestead situated on many acres of desirable land" or anything similar. In fact I just now discovered there is a page on this very site for permaculture skills you can pick up even if you live in an apartment: https://permies.com/t/129955/PEA-Permaculture-Experience-Apartment-dwellers

Now, if you've set as your criteria a fully detached single-family home surrounded by enough land to have a decent garden, I don't blame you, and the good news is it is probably within reach. [Caveat: I am basing this on the US. It might be a very different situation in other countries, though I suspect there are still at least some basic similarities.] As long as you don't care too much about being necessarily in the most trendy geographical areas or dwelling in a fancy mansion, there are lots of options that should be affordable for a young person with a steady job, especially if you are able/willing to learn more of the skills that save you money and make you more independent. I see examples all the time when I'm browsing Zillow.

The "steady job" and "able/willing to learn" part is critical, but I think it covers the vast majority of young people. Also, I'll just say because this was not obvious to me when I was young, there are some jobs where you start at low pay but are much more likely to advance to high pay relatively quickly; in my experience the skilled trades are like this while jobs like cashiering and customer service is not.

Daphne Rose wrote:Or we can discuss alternatives to ownership like ecovillages, and encourage activism.
* I don’t mean to discourage anyone this is just my experience. But I think maybe we need to focus less on ownership.

I am all for carefully and critically examining how we approach Stuff (not just ownership of, but use of, want of, need for, and attachment to). Really, the very way we structure our lives and our society in material terms ought to be fair game for questioning. I expect most people would exit that examination process with something fairly close to what they went in with, but it's still a good practice, and it may lead to more happiness & community, and less waste. But I don't think the reason for doing this should be based on the discouraging assertion, which I disagree with, that land is unaffordable to young people.

Last night I had, for the first time, a dream with a comedic element in it that caused me to wake up and laugh—more than once.

In the dream, my drummer’s former bandmates (who in real life I was friendly with) were conflated with some of our real-life mutual friends from high school days. In the dream they had come together to form a joke band, and had decided to call it Lead Zep’lin’, spelled exactly like that, with the apostrophes. They pronounced “Lead” like “leed”.

This hilarious band name is what caused me to wake up laughing the first time. I still giggle to recall it.

Once I fell back asleep, I kept having other dreams, and in them I would tell people I met about that band name, then wake myself up laughing again. I think it happened at least two more times.

Lately I’ve been having a lot of dreams where I’m in some public setting or other (at a grocery store, or in a hotel, at a sports stadium, etc.) when full-scale war breaks out around me suddenly and unexpectedly. In one dream I looked out a window and saw a foreign army flooding into the streets below and clashing with civilians. In another dream rockets started hitting the building I was in, and we were all rushing down stairways to get to the safer inner rooms of the building’s basement.

Sadly this is not a dream but reality for people in some parts of the world. I have family in one such place. I’m lucky for me these are just bad dreams. Still, I wake up feeling freaked out.

Thanks, everyone, for the helpful responses. More than one person gave advice related to where I intend to locate this project, and specifically about tree roots. That sounds important to know!

I'm quoting Rico, but this is intended as a reply to both Rico and John, and Anne who had questions/advice about that:

Rico Loma wrote:John has a long history of engineering and building, I am guessing he also means don't cover any roots of a big tree, many are underground but huge. Please be careful with placement, possible to build farther away from tree? And have no worries about roots whatsoever

In the section of the yard where I want for various reasons to locate the structure, unfortunately I don't think I have a way to get it farther from the tree and still not be on top of buried utilities, within easements, or where the ground stays mushy after it rains.

I am not on top of any big roots that I can see. I know now there are millions of buried roots. What portion of them are under my footprint, do you suppose?

This tree's trunk is probably 3 feet in diameter and its dripline extends something like 30' in all directions, so the whole footprint of my project right now ((6*11)/(pi*30*30)) takes up like 3% of the area under the dripline of the tree, give or take. And maybe like 10% of the area extending between any of the large roots I can see, which all run about 15' radially out from the trunk ((6*11)/(pi*15*15)).

Is the concern that I will deprive too many of the roots of their water? Their air? That the load of the structure weighing on them would be damaging? Something else?

Not clear what the issue with its placement is, so I am not sure how to even start thinking about alternatives.

Thanks again, this is fascinating as well as informative!

John C Daley wrote:
I would be concerned about covering the roots of any tree

Copy that, will stay between the roots and not cover them. 11x6 is plenty of room.

This will be a phased build as I gather materials, many of which I hope will be recycled/upcycled. Right now what I have is a pile of gravel sitting on a rectangular arrangement of landscape fabric and cardboard in my back yard--a sight that makes me very excited.

Tentatively, I hope to finish Phase I, a ready-to-build on foundation of some sort, near the end of autumn.

Why a sauna:

...Rather than a shed or a greenhouse or something.
A freestanding sauna has more of the same challenges or benchmark requirements as a house (weather-tightness, insulation, interior comfort, fire resistance, ventilation, possibly some basic plumbing and/or electricity, etc.) but scaled down to a single room, which makes this an ideal chance to experiment and learn how to use and combine various natural and conventional building techniques while also testing some concepts in passive design, which brings me closer to my main bucket list item of building my own house one day.
(Also my wife asked me to build her a sauna.)

About the site:

I'm in central Ohio. My sauna will be positioned under a large maple tree in the SW corner of my property, which slopes gradually (about 1:30) downward toward the west. The sauna will be about 10' inset from the right angle where two neighbors' privacy fences meet, and about 75 feet from the nearest exterior door of my house.

I tried to stay between two large parallel roots of the maple tree, so this determined the size and location of the landscape fabric footprint: it is roughly 6' x 11', with one of the long sides facing south. I could probably expand the footprint past the roots but I have a feeling it would be tricky.

Because of the maple tree, the structure will be mostly in shade during summer days and mostly in sun during winter days (when it's not gray).

Wishlist:

1. I've never worked with cob before, so I'd love to do a cob stove inside the sauna, or a cob stub wall on the north side of the sauna, or both. I've never worked with cob.

2. I'm also a bit curious to try shou sugi ban (charring the wood to protect it) or something similar on the exterior, but I don't know yet for sure what my cladding material will be. (Suggestions welcome)

The last phases will be a couple very small-scale off-grid systems, more to get introduced to and learn them than because they are really needed:

3A. Close shot: a solar panel and battery that can reliably power an interior light.
3B. Long shot: a rain catchment & water filtration system (also powered by the solar panel), with the end goal of being able to twist a faucet and get drinkable water that originally fell on the roof as rain.

Known unknowns:

- How should the rest of my foundation go?
I was imagining cinderblocks or ground-contact-treated 4x6s as a perimeter around my gravel, with my bandboard and floor joists going across those. (I do plan to dig a drainage channel around it first.) What alternatives to these materials/methods should I consider?

- I am confident I can salvage a lot of 2x lumber and sheet materials or find them cheap, which contributes to my idea to frame most of the sauna conventionally. What alternatives should I consider?

- What kinds of insulation should I consider, and where should I source it?

- I've never installed a vapor barrier or a roof before. I know how to inspect walls and roofs, and I'm used to running wires in them, but not the nitty gritty of how to construct them. Give me your knowledge!

Unknown unknowns:

I know basically nothing about saunas. It's a room you sit in, and there's something hot which makes the room hot, and you pour water over that hot thing and make the room steamy, and you sit there and it's good for you or something.

What hot thing should I use? Should it have a lot of thermal mass? How do I get all that steam out without rotting my sauna from the inside? Is there anything special about the construction of the interior (bench, walls, etc.) that I should know? Is there special wood you need to use? (Cedar I bet?) I am certain a sauna requires insulation but does it need to be special insulation because of the steam? Same question but for all the other materials too. What else am I not asking about because I don't even know about it yet?

Answers valued from anyone, but especially sought from people who've built saunas, weathertight outbuildings, and who've worked with cob and other "natural building" materials/methods.