Kris Johnson

I like pictures and bottle houses!

This bottle house is over 100 years old, your idea should work fine.

To get your 18" bottle brick just cut the top and bottom of 2 more bottles to 4" and duct tape them together, now you have an 8" bottle cylinder, then duct tape the other 2 bottles with just the tops cut off that are 5" to either end of your 8" bottle cylinder, voila 18" bottle brick. Wrap whole bottle brick in tin foil.

Clay, although lime is pretty carbon neutral.

Is there a reason I cant PM J.C.?

Here is another good video that will probably lead to more discovery    

This book is probably a good place to start: Essay on the Theory and History of Cohesive Construction Applied Especially to the Timbrel Vault written by Rafael Guastavino. I believe that all the structures he built are still in use today and NONE have suffered any deterioration, and they're all 100+ years old. I imagine you would be able to acquire all the knowledge you need to build such a structure from this book.  

As far as finding someone that actually does this kind of work MIT did some structures but I think they were temporary. But finding any real 1st world applications is probably nil.

The most difficult part would be to get any jurisdiction to permit such a structure and would probably also involve finding an engineer who really knew this type of construction and could convince the powers that be to sign off on such a structure.

There is also the Auroville earth institute, they do courses in such work but they are located in India.

I also like traditional nubian vaults this youtube video is really educational even if you dont speak spanish  


You said flat roofs are traditional to your wifes part of the world? How do they build them in her part of the world?


All that being said, you should probably build for your neck of the woods, or move to a part of the US where rain is minimum and a flat roof is suitable to the region. I have some land for sale if you wanna move to the desert!


WAIT! The majority of Guastavino's structures are in New York and Pennsylvania, I believe, so maybe it could work in Ohio. I think the trick would be something like with earthships where the roof is slightly tilted to the south so the winter sun melts the snow off the roof and doesnt allow much build up.

Thanks for posting the video too. I really like it as a learning tool more for what not to do,but the structures are beautiful. Planning goes a long way. It seemed like they just built the walls and then discovered vault building, then decided to put it on a structure that quit possibly could collapse, SCARY! Guastavino's vaults only rose 10% of the distance they spanned and used no form work, I think they would have had an easier time building had they used Guastavino's technique. Also Nubian vaults (true ones) transfer all thrust down to the walls, not outward, however the walls need to be a bit more substantial and you can only span about 10ft using adobe brick.


Just my two cents, have fun!

Another thought on pozzolans. Supposedly food grade diamotacious (spelled it wrong) is a pozzolan.

I am going to politely disagree with this statement

Mix sand and lime together, wait a couple of months and you'll be able to crush your test cylinders with your hand

. I have made lime mortar from lime bought at home depot, and it is still strong.

In fact! Ryan Chivers said that he will only use type s hydrated lime when available for his tadelakt projects as it was the only way he could make any gaurantee to his clients, and he knows his limes.

I'm no materials scientist but in my experience and others' it does its job. That is not to say that adding pozzolans to it is a bad idea, just that it performs well as a binder in itself.

how the heck do you decide which method to use

Really its up to you!

I think traditionally this was based on whatever method people in the region built with. People that live in regions where earthen construction is the dominant (or only) form of construction have been familiar with a method since they were children. If bricks are used in the area you use brick, if cob is used you use cob, rammed earth you use rammed earth ect, ect.

That being said I would say cob is slightly "faster" than any other form in the essence that the building material is going straight to the wall and drying there using no form work. However when you are building free form you have to make sure you are building plump (plumb ha ha) walls.

I would argue that adobe bricks are more diy friendly in that they are "easier" to keep plumb and straight although this method is a bit more labor intense. You have to make the bricks, let them dry, stack them near building site, then place them to build wall. The building material is handled more times than cob.

I know it must depend on the resources available

Usually all material required for earthen construction are close to a build site. With the exception of some parts of Florida? Clay is found in abundance right at the build site and sand can be found close by if not on the build site as well.

but is one better than the other for say thermal qualities?  

No, all earthen construction carry's the same thermal qualities all things being equal.

Cob is partially mud (I believe)

Cob (and all earthen constructions) are an approximate ratio of sand to clay usually 70-80% sand and 30-20% clay and straw around 10-20%. As a side note cob construction is really the only method requiring straw in the mixture. Adobe bricks do not require straw but is optional.

How does that handle rain, hail or other weather?

Quite well! Depending on annual rainfall and how much the roof overhangs to reduce exposure to weather and how high off the ground the earthen walls are.

And how long can they last?

As long as it is maintained, a very long time. There are cob homes in England that have been continually inhabited for 400, 500, 600, 700 + years. Taos Pueblo has been inhabited at least 550 years and possible as long as 1000. Shibam in Yemen is at least 500 years old. So quite a long time, as long as they are built correctly and maintained.

Are there builders out there who can help us achieve something as nice as the home in the link below

I'm sure there are.

Can walls be repainted?

Yes as long as its a lime based paint or a paint that will "breath".

Is a thatched roof practical in the US?

Practical? Its possible but I don't think it's practical as its not something that many people in the US know how to do (that I know of). In England there is a tradition of thatched roofs and still tradesmen that know how to maintain and build new thatched roofs. I think a tiled roof would be more reasonable to do.

Thanks for the help

You're welcome!

I feel like I don't know where to begin

This is a good place. I would read all the posts in the cob forum. Another good place is your backyard. Dig up some dirt mix it with water to a moldable consistency and make some bricks, let them dry. Do some drop tests, leave them out and see how they do in the weather.

Have fun!

What ever came of this?