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cob homes, always curved?  RSS feed

 
Gillian Owens
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I am going to be building my cob home within the next few months. I just got the land, we are clearing out the spot, and working on blueprints. My fiancé just can't bring himself to be content with curved walls. He says he can deal with it in some areas but not for the entire structure. Is it absolutely a REQUIREMENT for a cob house to have curved walls? I am seeing pictures on Google images of old English homes that are cob, and most of them appear to have straight walls. These are large homes as well. My fiancé has a lot of experience in building houses the traditional way and this will be his first cob home, mine as well. The only problem we have with cob is it being round. I have been researching websites to see if someone will explain why cob is round. Becky Bee in her book touches on it. But I am thinking if a home has a great foundation and sturdy form, with roof going up before cob walls, then would they still have to be round?
TradCobDevonWeb.jpg
[Thumbnail for TradCobDevonWeb.jpg]
Old English cob house, not curved
 
allen lumley
pollinator
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Gillian & Permies-Cloud : I am a little outside my skill set here, most of my knowledge comes from these threads, another good book that you should be able to get used at
Amazon books in good or better condition is '' The Hand-Sculpted House " Evans' et al !

The indigenous peoples of the Mediterranean will tell you what their grandmother told them '' It's so the devil can't hide in the corners'' !

It would be just as easy to say why not round, curved, look at the picture you picked, on the long wall facing us first there is a monolithic vertical chimney
structure, followed by three bracing abutments, the eves are inadequate at this location as the walls are stained with algae/moss, on the far end, you have two more builds
abutting the end wall and the chimney pot of a second bracing monolithic chimney. the end wall of the Cob Cottage closest to us also has a second structure added on latter.

To my eye it looks like a whole lot of making a virtue out of necessity and buildings added on to add to the structural integrity of the original building, as it is different from
Traditional Buildings it would be interesting to find out just how old the building Really is ! Hats off to the series of Cob Craftsmen who worked to keep it tight !

If you were going to build a pole barn type structure over a good foundation protected by french drains,and landscaping to carry surface water away from the stem walls and
then fill in/build-up starting with the windward side then basically you need only worry about the exterior walls being thick enough to support the weight from above and locking
every section together as you go from one weeks work on an area to the next ! For the good of the craft ! BIG AL
 
Jami McBride
gardener
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Location: PNW Oregon
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No, there are no 'shape' rules that must be followed.

However, round is much stronger of a shape...... So if your in a high winds, tornado type area you may want to go with a rounder shape. Possibly an octagon/yurt to give you flat surfaces for furniture and such. Check out these straw bale house plans http://www.balewatch.com/ for some interesting combo shapes. Straw bale plans will work well for any think-wall design you have in mind.

I agree with Al.... and would add: maybe some curved areas, alcoves, bays and such. Your working with cob so it would be a shame not to be creative while still giving your kitchen a right angle or two.

A gal in her seventies built her own cob cottage, she wanted a heart shaped house - wonderful, until she had to roof it. It turned out to be much more of a cost and project than anticipated. So while your designing do take into consideration the construction of the roof supports. It can be done, but some shapes and angles are just easier than others.

All the best with your new cob dream, I would love to see your progression pictures!

~Jami
 
Jay C. White Cloud
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Hello Gillian,

No, cob architecture does not have to be round, and historically most weren't, and many still built today by cultures that have used cob for millenia do not. What you are seeing done today is the "new age," and "back to earth" types reinventing the cob wheel, as it were. Most of these modern cob structures are built by amateur enthusiasts, some reading a few books, and a few with a little travel and academics behind them. Most are built from "concept," not practical training in any of the traditional building arts. I don't mean for this to sound like a condemnation of any kind, just a warning. Many folks are getting wrapped up in the romance of cob and what they see so many folks doing. For those of use with traditional training, we get alarmed. I would say, conservatively, that the majority of cob structures being built today, or in the last 10 years are built and facilitated by folks with less than 5 structures under there belt, most it is there first, and they are getting guidance from some that "love cob," but no little of other traditional building modalities, including the many vernacular and traditional styles of cob.

With that said...

Most cob structures, like the one in your shared photo for example are, or have an internal superstructure of wood framing often a timber frame. I would not recommend a novice even attempt a multi store "full cob" structure. It must have an internal armature of wood framing. In general I do not recommend cob to the novice builder, it is being romanticized by too many as be "really easy" to do. In some was it can be, but in many others there are things that are not being considered or understood (too many to even try to list here.) If you are doing this yourself as a first build, read everything you can get your hands on, and look at the traditional building methods for the best guidance in structure and durability, cob or otherwise. Ask and seek as out as much advice as you can. Yes curved walls are stronger if building "full cob" structures, but no stronger than "full cob" done traditionally with ramparts or other applicable traditional reinforcements.

Good Luck

 
R Scott
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Location: Kansas Zone 6a
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People just can't get their heads around the volume of work involved in cob until they DO IT. A 5 gallon bucket sized batch (which is a LARGE batch for stomping) weighs 75-100 lbs. And that makes about as much wall as ONE concrete block.

Those nice little cob bread ovens can have a TON of cob in them, literally. My bread oven (a little bigger than E&E's double chamber frog) weighs in somewhere between 3 and 5 tons when you include the rammed earth base.

Once you realize how many tons of material are in every foot of wall, you will do everything you can to minimize walls--and the most volume for the least circumference is a circle.

 
allen lumley
pollinator
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Gillian and the Permies Cloud : Jay C. White Cloud has vastly more experience in these areas than I do, and I will gladly step back and let him lead and not be afraid !

The first book I mentioned is writen like a good college text book for a make-up or College level 101 course that you have to take be cause your h. school didn't cover
it! I freely admit that it leans towards Curved walls out of caution and the safety of a certain amount of redundancy and Mass !

I really like the way that doing the planning stages of your house on the land that you will be building on is deeply explored, it is worth a look for that alone! blueprints
have a tendency to make you say, gee i wanted to save that big old tree but now I see it will have to go If I want that view !(everything is a compromise !)

Also from the 'more is more school' but a very friendly read ( like having a close friend who is experienced in these matters and shows up to help, and stays until the
project is done ) is ' The Cobbers Companion ' by Michael Smith, Cob construction lends its self to built-in-furniture, conversation pits, breakfast nooks and niches
for people and things, it also allows for freedom of expression of individual ideas which can have an 'Alice thru the Looking glass' effect on people ! Both Builders and
others following along behind !

You did not give a location, I would recommend reaching out, many Regional Permaculture Centers are Also caught up in the 'Cob is beautiful cycle,' and you may find a
local project that the two of you can volunteer at, get some experience and check out the craftsmanship and building talents of instructors, possibly in your near area.

For the Craft Big AL !
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