Subterranean Cob?

Hey all. I'm new to permaculture and natural building, so I'm trying to get as much information as I can as I begin planning my next phase of life, in which I hope to obtain my own land to start heading to full sustainability. In doing this research I am planning on trying to attend several workshops in my area, but I have a question I hope someone on here can answer.

Can cob homes be covered with earth?

This may sound like a stupid question on the surface, but here's my reasoning; All the cob I've seen is made with some sort of a roof to keep the rainwater washed well away from the structure to ensure it stands the test of time and natures erosion patterns.

So what if there is no actual roof? What if you want to bury the house in a hillside and cover it with a foot or more of soil and grass? Can a cob home support that weight even if the roof is supported with strong timber? What do you have to do to seal it should rainwater seep down?

Why do I want to know this?

Because aside from being a self reliant person, I am an unashamed Tolkien fan........ You do the math

So if anyone has any ideas or helpful information, please share! I look forward to reading what ideas or knowledge you can drop on me!

Hi Phil, et al,

Can cob homes be covered with earth?

Yes

So what if there is no actual roof? What if you want to bury the house in a hillside and cover it with a foot or more of soil and grass?

If designed and built well this will support an "earth wall" system of your choice...remember...designed well, and built well...

They very often are not, and there are more applicable modalities for fossorial architecture.

Can a cob home support that weight even if the roof is supported with strong timber?

If you have strong timber framing employed into the system design then your "earth wall matrix" does not have to be load bearing. I typically do not recommend that DIYers attempt "structural earth architecture" without a PE being involved or someone overseeing the project that has a minimum of 15 years experience in the design and facilitation of natural building materials.

What do you have to do to seal it should rainwater seep down?

If water is seeping down (a common problem) the design and construction is flawed...or its a very old and poorly maintained structure.


Hope that helps you Phil, and I would love to be of further assistance as I too am a "Tolkien Geek!" REMEMBER, this may not be the "best" or most applicable building system to use and I would point out that "Tolkien" is a "Fantasy" genre of literature...so is the architecture. It can be done...done naturally...and done well if you want it...it is neither inexpensive or easy to achieve.

Regards,

j

Awesome! This is the kind of info I need to get my creative juices flowing and my thinking cap on. I totally get what your'e saying about the fantasy thing. I'm not so much of a dreamer to try and build one if it isn't structurally sound. After all it is a house I want to live in! My end goal is to build something similar and functional I can live in cozily using materials mostly from my own land or recycled; In essence, it would be cool if the initial building, waterproof and livable minus all the extra aesthetic details could run me less than $10,000. My brother an I are in the stages of planning out a business plan starting with a sawmilling operation and eventually moving on to growing organic produce and having an organic orchard. This house is one we thought would make for a great story and first build, then when we build our own houses for ourselves, we have a friend who has had a dream of running her own bed and breakfast, and thought it would make a great vacation house to rent out.

what would you suggest looking into to help me figure out the answers and questions you put forth about my initial problem?