But, what isn't shown in this video is how easy it is to plaster over light straw clay walls! They are already covered with clay slip, so a simple wetting, and then apply your plaster of choice. A dream to work!
Best architecture ever I saw building ecofriendly, stable, warm and cheap technique to build a house. It is mostly useful for those who has less money to build a house for their families. Keep it up!
If you use more clay in the straw it will be easier to compact and will have even better overal quality and durability. A clay and straw mix lasts for hundreds of years without rotting. Friends of mine opened a wall made with that mix fro a building of the eighteenth century and it was intact.
I saw a russian video and their method seems a LOT EASIER. Big tub filled with the watery clay(slip) a little thinner than a salad sauce. They DIPPED the straw into the tub and throw it aside on an incline metal sheet that take the overfill back in the tub. From that point you go to the wall to compact it. Less TIME CONSUMING , less manipulation, more job done in a day.
I found what he is talking about in these 2 videos: ruclips.net/video/YGUDojRuw-M/видео.htmlsi=36U0ps7JHp-w15iw ruclips.net/video/fh4WbZNL2ns/видео.htmlsi=sP6ScNMWDzkdXug8
The material is cheap but it is labor intensive so in the end no much of a saving depending on the labor cost in your area. Of course If you have a half of dozen friends to help it reduces the cost I like the fact it is the healthiest and most environmental material once could use to build a house.
Labour intensive can mean for some bringing the community together to share and pass on wisdom, enhance community spirit and get fit ;-) But this isn't always possible for everyone 💗
There are many benefits of building a small house. Lower energy costs, more communicative, intimate family unit, and perhaps most importantly of all: quicker build time. I don't know about you guys, but I know I would NEVER want to build a cob house the size of a mcmansion knowing how long it can take to build up even a small cob house with 30 people working on the project at the same time. I've seen conventional houses and even large hospitals built up in a matter of weeks far faster than cob houses can be.
@@YaBoiTrickyRicky As with anything in life, it boils down to three simple options which are: good, fast and cheap, but you can only choose two of them. Cob is good and cheap, but it's not fast while timber framing, sheet rock and drywall are fast and cheap, but they are not good.
What is the ratio of mud water? How much of clay and how much of sand need to go in there? What consistency is required for the straw and mud? Too watery or not too watery or a bit dry? In what intervals/when to move the frames to next iteration? Because it's not ideal to move immediately and keep compacting. Do we need to treat the straw for termites?
I've been to a course in permaculture for cob light clay straw and earthbags. The real answer is not a mathematical ratio but a feeling in your hands when you know it's right. However, the number get you close. Clay is wet as is, but you make it wet straw/ clay. There is not and sand or mud in a true clay straw. That's in the cob or plaster
Thank you for the very informative material! Regarding the difficult parts in the upper side of the walls, I was thinking about making 1 slip-straw brick for each space. I'd just cast it on the ground, let it dry and then place it up there. What do you think?
You can do multiple levels in a cob building. You just have to slope it inwards like it's a subtle pyramid of sorts if you're doing more than two stories.
Type in the RUclips search bar "Shibam Yemen" and you will see a small town built in the 1500's full of cob buildings that are 6, even 7 stories high. It has the nickname of "Manhattan of the Middle East" and it looks absolutely gorgeous.
Hempcrete would make a better building envelope and your material cost would go up but your insulation value would drastically increase and you could also eliminate a lot of the thermal bridging at the studs.
Yeah, I just found a source for hemp shiv. I want to do a hempcrete building sometime soon. The straw-clay is definitely cheaper though, which was nice right now.
I'm curious about this...they say hempcrete is generally 1.7 R value per inch. How does light straw clay compare in R value? Also ... Can't you bury the studs with straw clay just like is typically done with hempcrete? After all, they are both compacted into forms, and the construction process seems the same - just different materials?
It's worth checking out the Cobbauge project over in the UK. They developed a dual layer light cob and dense cob to have a reasonable thickness on monolithic cob structure that could pass UK and French building regs (30cm light cob and 30cm dense cob). They tested reeds, straw and hemp shiv for insulation value for the light cob and hemp shiv came out best. If not using the dense cob beside it and using timber frame for structure though, I wonder if maybe a 5% straw 45% hemp shiv mix might be worth trying to get some of the structural quality of the straw for binding the light cob, as their light cob mix with hemp shiv was very friable, like breakfast cereal. May also need to use a metal grid for the forms and leave in place longer as would need longer to gain structural strength from drying. I'd say you'd definitely be wanting to render/plaster with lime/clay plaster to further lend some structural integrity. They've various academic papers reporting on their experiments, so useful data when talking to officious folk. They've also some really useful practical guides and videos for builders and architects.
Thanks for this great, informative video! I am planning on building a straw-clay structure much like this (but quite a bit bigger) in South Africa. I have a question that may be a little silly, but hey I am learning ! I noticed that there are no diagonals in the wooden structure. I understand that they would pose difficulties when filling , but how do you maintain the structural integrity of the building without diagonals? Does the straw-clay do their job ?
Yeah, basically. Once all the vertical trusses are set, and the top plate is put in place over the tops of them the framing is rigid. Then the addition of the straw-clay adds even more rigidity to the walls. Plus, the roof too.
Some structural engineers will require diagonal bracing or wind bracing for your structure. It depends on your specific area and building codes. Diagonals can be added on either the inside or outside section of the trusses.
Have you ever used light straw clay as a thermal and acoustic roof insulation? I wondering if it would be possible (and effective) to use light straw clay panels beneath a single metal sheet roofing.
You could, but issues to address are adequate ventilation, sealing the light straw clay on all sides to prevent spontaneous combustion under the metal roof. Air gaps, etc. You would also need to devise a way to keep secure the light clay straw into the roof/ceiling and prevent falling.
Is there a ratio of water/clay to straw? It seemed very dry when you were mixing and compacting. Also assuming it has to stay above freezing for a period of time in order to set/cure properly?
There's no set ratio that I've ever come across. Some people prefer a more 'muddy' mix than others. I actually do too because it compacts a little easier. However, my soil would not dissolve to the muddy consistecny to do that so it was more of a 'lite' covering of muddy water. This is how most straw-clay tends to be though. Just a runny muddy water covering the straw.
@@thiscobhouse We got the clay from a farmer for free. We sieved the clay and dissolved it in water in larger basins (sawed open old metal tanks from the scrap yard). Then we put the straw in it so that it was completely soaked. At the end, we placed it in the formwork and compacted it. It takes longer to dry, but it makes the walls very solid. As you said, compaction is easier. Greetings from Germany
I live in Northeast of Thailand and the wheather nowadays near 50 f. in summer when I see your works I have a idea to build my place in the farm. my concern is termite will distroy all words frames so I will use metal frame instead. thank you.
The issue with using metal for support of light clay straw is condensation issues next to the metal. The moisture runs down the metal members of the wall and causes rot at the base of your walls. Using wood/bamboo/laminate boards doesn't have this happen. You will need to figure out how to make your walls termite resistant. Some folks suggest adding borax to your clay slip to deter termites. I don't know if that will be enough. Good luck!
Very cool. Seems much less labor-intensive than Cob. I did a Cob workshop once. So it sounds like you're saying this straw-bale has much more thermal mass than cob?
This method is insulative, not thermal mass. Thermal mass stores heat like a battery in the material itself. Insulation, like light straw clay or fiberglass traps air, which keeps heat from moving from the heated side to the cold side. More R-value means it takes longer for the heat to move across to the cold side.
I was surprised to see you using rebar for horizontal structure, as I imagined it might create recurring condensation in the middle of your light clay structure. But I also noticed it was red, as though sheathed with some sort of plastic insulation. I'm no builder so am not a connoisseur of rebar, perhaps you could explain whether this is an isdue and if a particular type of rebar is recommended?
I used a fiberglass rebar in this one. Tbh, I'm not too worried about the condensation issue either in here. Perhaps it could happen, I don't really know. But if it did, the moisture should be able to escape easily before any problem occurred. Just my first thoughts anyway.
Any kind of wood, bamboo, or natural fibers can take the place of the rebar. The function of the rebar in this instance is to keep the light straw clay panels from popping out of the wall. When we did ours, we used small nails and sisal twine to hold our panels in. Tied them in every foot or so, and plastered right over the nails and twine. Easy.
It isn't very hard to pack in the tops of the walls when you get there. No matter what interesting shapes you have to work around. Remember he will finish this with a plaster, so you won't see this when it is done.
When we did ours, we called it making "salad" Just wet enough to get the clay to stick to the straw. We used pitchforks on plywood to "toss" the salad, as we added the clay slip "dressing". A good coverage of clay slip is all you need to stick it together. Also it doesn't have to be so tightly compressed in the wall. Small air voids are okay. You'll know how tightly it needs to be compressed when you pull off one of the slip forms, and the straw falls out. :) You get the feel for it pretty easily. :)
If you can make pots with your clay, it will work for this. Clay has to be "sticky" when wet. You'll know when you are digging and it cakes on the bottom of your boots and you have to scrape it off. LOL Seriously, most clays will work for this application.
Nobody is saying its better than strawbale. Every wall system has it's own pros and cons. I like this straw-clay method because the framing provides load bearing (also good for getting permits), and the straw is preserved better in the clay mix. But to each their own. But honestly, the wall framing is the easiest/fastest part of the whole build, imo.
We are in a temperate climate with only small amounts of snow. Just increase the R value by making the walls wider. The larsen trusses can be built to whatever width you need.
Not at all. The high foundation and the long roof overhangs protect the straw-clay walls. At the end, the walls will be covered with a waterproof lime plaster too.
I'm wondering what the wind load would be on these walls? If you are going for super strength walls then would it be ridiculous to do the Larson trusses with 2x6 or 2x8?
You say that the straw-clay has a pretty good r-value and is cheap to make. The industry doesn't like that so you better go to the bank and barrow thousands just to buy roxul :-) Here in Nova Scotia you are not even allowed to use your own lumber for your house.
So an R value of 12 for 9 inches - or about an R value of 1.3 per inch? That sounds kind of low... or are you counting on a high U value as well? This doesn't seem like it would do well in a really cold climate unless it was really thicker walls?
I have a suggestion. What if you made a seperate frame on the ground and did a compact let it settle, removed it by taking screws out and installed it at top where its difficult to reach.TRY IT
It could work. But you would need that 3 week drying time. And the material tends to crumble if handled roughly. But I could a setup where you made a bunch of them and cut them to length with a saw. But the clay will dull your tools quickly.
Well this video just convinced me to stick with regular straw bale construction. What a pain... Thanks for the vid
But, what isn't shown in this video is how easy it is to plaster over light straw clay walls! They are already covered with clay slip, so a simple wetting, and then apply your plaster of choice. A dream to work!
Best architecture ever I saw building ecofriendly, stable, warm and cheap technique to build a house. It is mostly useful for those who has less money to build a house for their families. Keep it up!
If you use more clay in the straw it will be easier to compact and will have even better overal quality and durability. A clay and straw mix lasts for hundreds of years without rotting. Friends of mine opened a wall made with that mix fro a building of the eighteenth century and it was intact.
The straw then was thicker aswell
This will be a very durable wall, because it will be finished with plaster on the outside and inside. Easy!
Super nice brickwork. Impressed!
Great series. Really neat seeing it go up over the last 3 videos. Excited for part 4
Glad you enjoy it! Thanks!
I saw a russian video and their method seems a LOT EASIER. Big tub filled with the watery clay(slip) a little thinner than a salad sauce. They DIPPED the straw into the tub and throw it aside on an incline metal sheet that take the overfill back in the tub. From that point you go to the wall to compact it. Less TIME CONSUMING , less manipulation, more job done in a day.
Thanks for sharing! I'd love to see that video.
Any chance you have that video in your history and can share it's link?
I would also like to see this video.
I found what he is talking about in these 2 videos:
ruclips.net/video/YGUDojRuw-M/видео.htmlsi=36U0ps7JHp-w15iw
ruclips.net/video/fh4WbZNL2ns/видео.htmlsi=sP6ScNMWDzkdXug8
I saw someone do hemp-lime crete round house looked solid af
The material is cheap but it is labor intensive so in the end no much of a saving depending on the labor cost in your area. Of course If you have a half of dozen friends to help it reduces the cost I like the fact it is the healthiest and most environmental material once could use to build a house.
I see labor intensive as a plus.
Labour intensive can mean for some bringing the community together to share and pass on wisdom, enhance community spirit and get fit ;-) But this isn't always possible for everyone 💗
Poor people may have more time than money and no need to get it done in a day.
There are many benefits of building a small house. Lower energy costs, more communicative, intimate family unit, and perhaps most importantly of all: quicker build time.
I don't know about you guys, but I know I would NEVER want to build a cob house the size of a mcmansion knowing how long it can take to build up even a small cob house with 30 people working on the project at the same time. I've seen conventional houses and even large hospitals built up in a matter of weeks far faster than cob houses can be.
@@YaBoiTrickyRicky As with anything in life, it boils down to three simple options which are: good, fast and cheap, but you can only choose two of them.
Cob is good and cheap, but it's not fast while timber framing, sheet rock and drywall are fast and cheap, but they are not good.
Thanks for this information, I've found it difficult to find decent info on light earth on the internet. Looking forward to more videos! 🙏
What is the ratio of mud water? How much of clay and how much of sand need to go in there?
What consistency is required for the straw and mud? Too watery or not too watery or a bit dry?
In what intervals/when to move the frames to next iteration? Because it's not ideal to move immediately and keep compacting.
Do we need to treat the straw for termites?
I've been to a course in permaculture for cob light clay straw and earthbags. The real answer is not a mathematical ratio but a feeling in your hands when you know it's right. However, the number get you close. Clay is wet as is, but you make it wet straw/ clay. There is not and sand or mud in a true clay straw. That's in the cob or plaster
Borax should work against termites. In the clay water
Amazing!!
Thanks!
Thank you for the very informative material!
Regarding the difficult parts in the upper side of the walls, I was thinking about making 1 slip-straw brick for each space. I'd just cast it on the ground, let it dry and then place it up there. What do you think?
Many companies are doing that
I really like it
I would love to see how to do a second story/loft in a cob building.
You can do multiple levels in a cob building. You just have to slope it inwards like it's a subtle pyramid of sorts if you're doing more than two stories.
Type in the RUclips search bar "Shibam Yemen" and you will see a small town built in the 1500's full of cob buildings that are 6, even 7 stories high. It has the nickname of "Manhattan of the Middle East" and it looks absolutely gorgeous.
Nice man. Looking forward to seeing it finished.
Thanks 👍
Brilliant as always
Works for hempcrete?
Yes, absolutely! I want to try it with hempcrete sometime soon.
Hempcrete would make a better building envelope and your material cost would go up but your insulation value would drastically increase and you could also eliminate a lot of the thermal bridging at the studs.
Yeah, I just found a source for hemp shiv. I want to do a hempcrete building sometime soon. The straw-clay is definitely cheaper though, which was nice right now.
I'm curious about this...they say hempcrete is generally 1.7 R value per inch. How does light straw clay compare in R value?
Also ... Can't you bury the studs with straw clay just like is typically done with hempcrete? After all, they are both compacted into forms, and the construction process seems the same - just different materials?
Hemp does the same as straw. Its just the hype that makes it more appealing. But in practical terms it's the same.
Hemp is fireproof straw isn't.
It's worth checking out the Cobbauge project over in the UK. They developed a dual layer light cob and dense cob to have a reasonable thickness on monolithic cob structure that could pass UK and French building regs (30cm light cob and 30cm dense cob). They tested reeds, straw and hemp shiv for insulation value for the light cob and hemp shiv came out best. If not using the dense cob beside it and using timber frame for structure though, I wonder if maybe a 5% straw 45% hemp shiv mix might be worth trying to get some of the structural quality of the straw for binding the light cob, as their light cob mix with hemp shiv was very friable, like breakfast cereal. May also need to use a metal grid for the forms and leave in place longer as would need longer to gain structural strength from drying. I'd say you'd definitely be wanting to render/plaster with lime/clay plaster to further lend some structural integrity. They've various academic papers reporting on their experiments, so useful data when talking to officious folk. They've also some really useful practical guides and videos for builders and architects.
My cabin has rough cut 2x6 walls and R22 batt insulation. To reach that level with straw bale the walls would have to be 18" thick!
But will it still be standing when the big bad wolf comes?
If you live in Minnesota, their construction codes now mandate all new construction housing have 30" (2.5 FEET!) of spray foam insulation.
@@YaBoiTrickyRicky In the walls or ceilings?
Thanks for this great, informative video! I am planning on building a straw-clay structure much like this (but quite a bit bigger) in South Africa. I have a question that may be a little silly, but hey I am learning ! I noticed that there are no diagonals in the wooden structure. I understand that they would pose difficulties when filling , but how do you maintain the structural integrity of the building without diagonals? Does the straw-clay do their job ?
Yeah, basically. Once all the vertical trusses are set, and the top plate is put in place over the tops of them the framing is rigid. Then the addition of the straw-clay adds even more rigidity to the walls. Plus, the roof too.
@@thiscobhouse thanks so much ! Really appreciate your feedback .
Some structural engineers will require diagonal bracing or wind bracing for your structure. It depends on your specific area and building codes.
Diagonals can be added on either the inside or outside section of the trusses.
Have you ever used light straw clay as a thermal and acoustic roof insulation? I wondering if it would be possible (and effective) to use light straw clay panels beneath a single metal sheet roofing.
You could, but issues to address are adequate ventilation, sealing the light straw clay on all sides to prevent spontaneous combustion under the metal roof. Air gaps, etc. You would also need to devise a way to keep secure the light clay straw into the roof/ceiling and prevent falling.
Is there a ratio of water/clay to straw? It seemed very dry when you were mixing and compacting. Also assuming it has to stay above freezing for a period of time in order to set/cure properly?
There's no set ratio that I've ever come across. Some people prefer a more 'muddy' mix than others. I actually do too because it compacts a little easier. However, my soil would not dissolve to the muddy consistecny to do that so it was more of a 'lite' covering of muddy water. This is how most straw-clay tends to be though. Just a runny muddy water covering the straw.
@@thiscobhouse We got the clay from a farmer for free. We sieved the clay and dissolved it in water in larger basins (sawed open old metal tanks from the scrap yard). Then we put the straw in it so that it was completely soaked. At the end, we placed it in the formwork and compacted it. It takes longer to dry, but it makes the walls very solid. As you said, compaction is easier. Greetings from Germany
I live in Northeast of Thailand and the wheather nowadays near 50 f. in summer when I see your works I have a idea to build my place in the farm. my concern is termite will distroy all words frames so I will use metal frame instead.
thank you.
over 50 C°
The issue with using metal for support of light clay straw is condensation issues next to the metal. The moisture runs down the metal members of the wall and causes rot at the base of your walls. Using wood/bamboo/laminate boards doesn't have this happen.
You will need to figure out how to make your walls termite resistant. Some folks suggest adding borax to your clay slip to deter termites. I don't know if that will be enough.
Good luck!
Very cool. Seems much less labor-intensive than Cob. I did a Cob workshop once. So it sounds like you're saying this straw-bale has much more thermal mass than cob?
This method is insulative, not thermal mass. Thermal mass stores heat like a battery in the material itself. Insulation, like light straw clay or fiberglass traps air, which keeps heat from moving from the heated side to the cold side. More R-value means it takes longer for the heat to move across to the cold side.
I was surprised to see you using rebar for horizontal structure, as I imagined it might create recurring condensation in the middle of your light clay structure. But I also noticed it was red, as though sheathed with some sort of plastic insulation. I'm no builder so am not a connoisseur of rebar, perhaps you could explain whether this is an isdue and if a particular type of rebar is recommended?
I used a fiberglass rebar in this one. Tbh, I'm not too worried about the condensation issue either in here. Perhaps it could happen, I don't really know. But if it did, the moisture should be able to escape easily before any problem occurred. Just my first thoughts anyway.
Any kind of wood, bamboo, or natural fibers can take the place of the rebar. The function of the rebar in this instance is to keep the light straw clay panels from popping out of the wall.
When we did ours, we used small nails and sisal twine to hold our panels in. Tied them in every foot or so, and plastered right over the nails and twine. Easy.
What about if I put some lime in the composite ?
Thanks for the video
Lime isn't needed. Added expense. Save the lime for the finish plaster. ;)
Would it be a good idea to leave the top part of the framing unfinished (no roof, top plates) to make packing the material easier?
It isn't very hard to pack in the tops of the walls when you get there. No matter what interesting shapes you have to work around.
Remember he will finish this with a plaster, so you won't see this when it is done.
How wet with muddy clay are you getting that straw so it holds form when it drys?
When we did ours, we called it making "salad" Just wet enough to get the clay to stick to the straw. We used pitchforks on plywood to "toss" the salad, as we added the clay slip "dressing". A good coverage of clay slip is all you need to stick it together. Also it doesn't have to be so tightly compressed in the wall. Small air voids are okay. You'll know how tightly it needs to be compressed when you pull off one of the slip forms, and the straw falls out. :) You get the feel for it pretty easily. :)
Just one question... How would you insulate the first part of the house, where the bricks are? Thank you, from Spain.
You could either not do the brick, and bring the straw-clay walls down to the floor, or you could install insulation in the middle of the brick wall.
What is the cost per square foot for a DIY building like this.
Is this really any better than usual construction? That is a low R-value for all that work, all that thickness, and all that lumber cost.
Better? maybe. Yes, lower R-value. But for interior walls, this provide superior sound dampening between rooms.
How do i know what Clay i use in My region ? Is it the same they ate making pots of it ?
If you can make pots with your clay, it will work for this.
Clay has to be "sticky" when wet. You'll know when you are digging and it cakes on the bottom of your boots and you have to scrape it off. LOL
Seriously, most clays will work for this application.
Can you use chopped straw?
Yes.
But works better with long straw.
the reason for the double wall framing is for eliminating thermal bridging (heat transfer)......the rebar is useless........
He uses the rebar for extra strength I think. He likes his buildings ultra strong
Is there a video comparing rammed earth to straw-clay? Its the same as cob it seems?
This recent video I did might help answer some of your questions: ruclips.net/video/Hme0sb_1Kvk/видео.html
So much framing and grunt work. How is this quicker, cheaper or better than straw bale?
Nobody is saying its better than strawbale. Every wall system has it's own pros and cons.
I like this straw-clay method because the framing provides load bearing (also good for getting permits), and the straw is preserved better in the clay mix. But to each their own.
But honestly, the wall framing is the easiest/fastest part of the whole build, imo.
We used strawbale for our exterior walls. And light straw clay for interior walls. It is another tool to have in your natural building tool kit!
Чем ты делаеш жыдкость? Штоб потом наливать на малому..
R12 - you dont have snow do you? Context is important. I am here to learn to use this build idea. Thank you!
We are in a temperate climate with only small amounts of snow. Just increase the R value by making the walls wider. The larsen trusses can be built to whatever width you need.
I was thinking the same. A single 2x4 wall has an r value of 13.
For a better perspective of the amount of straw needed. Please clarify on average what is the weight of the 35ish bales used for this build?
Most farmers making standard square bales aim for 40 pound bales. so 40 X 35 = 1400 pounds of straw.
Are you not worried about water damaging the exposed straw walls?
Not at all. The high foundation and the long roof overhangs protect the straw-clay walls. At the end, the walls will be covered with a waterproof lime plaster too.
@@thiscobhouse Does the Lime plaster add any r value or is it too low to matter? Thanks, Alex! Great content!
The lime plaster is relatively solid and not a significant contributor to the r-value.
I'm wondering what the wind load would be on these walls? If you are going for super strength walls then would it be ridiculous to do the Larson trusses with 2x6 or 2x8?
Not ridiculous, but probably not necessary. I can't measure the wind loads, but I'm sure this building can withstand A LOT.
The depth of the top/bottom chord doesn’t add to the strength of a truss. The depth of the web does. You could probably even get away with a 2x3.
How much do you charge to build these types of houses?
How to grow my a tree in blackjard??
Definitely the wrong video to ask this question but, I do hear eucalyptus regnan trees grow quickly!
Can I use pine straw?
Yes.
The wooden frame isn’t insulated. Doesn’t that create a cold bridge?
Sure does!
@@thiscobhouse Oh yes, I reviewed the video and you can put the clay straw between the trusses. Great video. I learned a lot.
You say that the straw-clay has a pretty good r-value and is cheap to make. The industry doesn't like that so you better go to the bank and barrow thousands just to buy roxul :-) Here in Nova Scotia you are not even allowed to use your own lumber for your house.
Canada is communist.
Big Lumber has to protect itself from home sawyers!
I must have missed it, can someone tell me what the R Value was for these walls?
About R 1.5 per inch of thickness. I think it can vary depending on how compacted the straw mix is though.
So an R value of 12 for 9 inches - or about an R value of 1.3 per inch? That sounds kind of low... or are you counting on a high U value as well? This doesn't seem like it would do well in a really cold climate unless it was really thicker walls?
The walls are generally wider than what I'm doing here.
I have a suggestion. What if you made a seperate frame on the ground and did a compact let it settle, removed it by taking screws out and installed it at top where its difficult to reach.TRY IT
It could work. But you would need that 3 week drying time. And the material tends to crumble if handled roughly. But I could a setup where you made a bunch of them and cut them to length with a saw. But the clay will dull your tools quickly.