[ eco / d / comp / bod / tek ] [ home ]

/eco/ - Ecology

Networked living things
Password (For file deletion.)

File: 1610359034144.jpeg (63.56 KB, 640x467, lehm_holzleichtlehmhaus.jpeg)


Hi. I'm not sure how this works, but in the interest of furthering the exploration here, I add a little-known gem here. You will not find not much about this building technique in the English language and much less on English-language internet. Most of it is in German and practiced by people not very interested in books to be honest. So here's a short version in case someone might want to use this and can try to dig deeper.

Review of the book: "Bauen Mit Leichtlehm: Handbuch Für Das Bauen Mit Holz Und Lehm"
Have not read this book, but have worked with the technique it describes and heard this was the best handbook out there. It describes a type of natural building technique called "Light Clay" (Leichtlehm) which is ecologically sound with great insulation properties, as well as providing a breathable membrane to the house by diffusing gasses from inside to outside (both water vapor and toxic compounds, which is a structural pest in modern buildings). It is also immensely low-tech, uses materials that can often be sourced extremely locally and the whole structure of the building is practically compostable. What I like about the technique is it lends itself easily to straight building structures and doesn't automatically end up in the Hobbit-like clay structures you find in much COB aesthetics. We built most of a two-storey house in Light Clay.


File: 1610359164918.jpeg (63.94 KB, 550x550, leichtlehm_konstruktion_1.jpeg)

* Low-tech because you really only need the frame of a building (e.g. built in wood), a pitchfork, a plate of plywood, a wheelbarrow and some human hands. If you have access to one, a machine that blend clay and water into a slurry and another machine that can blow the clay slurry onto straw is a great improvement. But it is not necessary, which means it's possible to build houses with very little equipment. The basic protocol is: Mix clay and water to a slurry - Mix into straw so all is covered in the slurry, use pitchfork to tip over several times - Move straw-clay blend in wheelbarrow to building frame and pack it by hand, so to minimize large air holes, using a plywood plate to keep the clay from falling out of the frame - leave plate on until straw-clay-mix is dry and packed enough to not fall out - gradually take away plate so the mix can dry thoroughly - build your way up the frame.

* Materials can be sourced often very locally. You need: Clay, water and straw. Where I live, clay is abundant in the underground and can often simply be taken from literally underneath the future house, when you dig out the foundation anyway. Straw can be bought from a local farmer on the cheap and it's a great material: lots of air pockets inside the straw, which insulates (both heat and sound), and biodegrades well. A few chemical additions can help making the slurry, so it becomes smoother, but these do not compromise the biodegradability and are not necessary either.



"Clay, water and straw"

You forgot one or two main ingredients here.

A hint: what is concrete made of?

Also I wonder why sticking to same-old boring, symmetric architecture that might not hold its own weight anyways, with such heavy materials. Maybe research on archaic houses, both Precolombian and Antique/Medieval. Humans used to make it with so much better taste…


Is it any better than regular log cabin built with just two axes, or even one if you don't need hewing? I see straight timber beams cut with modern mechanized sawmill, a laughingly thin filling of clay and single-glaze windows on your pictures. Maybe something like this would make sense in Africa or where you come from, OP. A carpentry manual from 1850 describes fachwerk structure in following manner: "Buildings of this sort are built for dwelling only in warm country and come in two- or three-floor varieties, in colder country only summer dwellings, warehouses, stables, barns, etc. are erected in this fashion."
You have very strange understanding of what mesoamerican and european medieval architecture looked like. Especially if we talk popular dwelling, not fortresses or places of gathering built with slave labor. The most popular easiest design was semi-underground thatched roof mud hut and it still is in some parts of the world, something less primitive than what OP describes, that thing came after 16th century when river sawmills were become widespread.
I'm not sure what you mean calling symmetric architecture being unable to hold it's weight. On the contrary, all self-supporting structures ought to be symmetric.


Not sure how to respond to respect the threaded nature of this forum, but I hope it ends up the right place.

@99: That's right, I forgot sand, thank you for noticing. The offensive sarcasm I don't understand. Maybe I misunderstood this forum … As to the shape of the building: You can build in whatever shape you want. Some reasons people might have for building in squares are: Wooden planks are easier to build with in squares, it's easier to hang things on the inside walls if they are not round etc. You assume the materials are heavy, but they are not. A block of Light Clay is extremely lightweight (hence the name), but keeps a great insulation ability because of the many air pores (COB for example has close to zero air pore space).

@101: Great questions. Again, you can make the dimensions in many ways. The technique was developed in Germany and has been adopted as far North as Sweden to my understanding. You can find a lot of old fachwerk in Sweden by the way, so I don't know what your 19th century manual means with warm climate, perhaps everything is relative :) The house I took part in building was in a cold temperate climate and had much thicker walls. The filling you see in the second picture is not clay, it is mostly straw covered in the clay mixture – this is why it insulates so well. You could for sure make the wooden frame differently too and with hand cut planks if you don't have access to a machine. I would be surprised if the insulation capacity of even relatively thin Light Clay walls does not far surpass log cabins, but don't have the data with me (I'm sure this is possible to find). Wood is surprisingly a pretty poor insulation material, because the air pore space is fairly low.

[Return][Go to top] [Catalog] [Post a Reply]
Delete Post [ ]
[ eco / d / comp / bod / tek ] [ home ]