Cob Building - A Green Technology

Dogon cob houses and thatched roof in Mali.
Dogon cob houses and thatched roof in Mali. | Source

Cob, a Natural Construction Method

Cob is also called "cobb" and in Welsh, "clom." It is an all-natural building material containing a mix of subsoil, water, and fibrous organic materials like straw. Sand or clay is sometimes added for strength.

Pyramids - Stone and Cob Techniques

Click thumbnail to view full-size
Although many Egyptian Pyramids are formed of stone as pictured, some others were made of sun-hardened adobe-like bricks made with straw.Cob House - Kukherd, Iran. This work resembles in appearance both stone pyramids and smaller cob pyramids, as well as adobe buildings.
Although many Egyptian Pyramids are formed of stone as pictured, some others were made of sun-hardened adobe-like bricks made with straw.
Although many Egyptian Pyramids are formed of stone as pictured, some others were made of sun-hardened adobe-like bricks made with straw. | Source
Cob House - Kukherd, Iran. This work resembles in appearance both stone pyramids and smaller cob pyramids, as well as adobe buildings.
Cob House - Kukherd, Iran. This work resembles in appearance both stone pyramids and smaller cob pyramids, as well as adobe buildings. | Source

Adobe, Pyramids, and Cottages

After reading for years about Native American and Mexican adobe houses and the construction of the Egyptian Pyramids, I realized that these were both examples of cob building. Checking at the time with historical records, modern investigative research, and personal contacts in both Egypt (archaeology) and in New Mexico, this was confirmed in certain ares of each locale.

The same materials were used and are still used in parts of NM; sometimes bricks/blocks were formed, and adobe has been molded and still is among small Native American communities or pueblos.

The living roof on this cob house draws customers to buy organic popcorn to help support Stanley Park's ecological programs in BC.
The living roof on this cob house draws customers to buy organic popcorn to help support Stanley Park's ecological programs in BC. | Source

English Cob Builders

Only after this did I find many examples of cob building in England - and then in the United States - by green businesses set up to build these structures, and by eco-friendly individuals on their own.

Several people have written books about cob building and materials that you might check out of the library or find at your local book store or green building supply outlet.

  • Building Green: A Complete How-To Guide to Alternative Building Methods Earth Plaster * Straw Bale * Cordwood * Cob * Living Roofs by Clarke Snell and Tom Callhan is excellent. This book provides step-by-step instructions and dozens of correlated pictures.

Cob Building References

Midwest Cob

More recently, I have looked at the materials of several house plans for cob building and examining the printed materials used in construction of a cob house in Knox County, Ohio. I've come up with some foundation information about arches and, while what I have discovered may not fully meet your needs, I have supplied information for additional specific places to go for help.

I've also supplied several links to cob building sites that will answer email questions about cob related projects, and a couple of descriptions of some very good books that illustrate methods and give instructions in cob building.

It appears that the sturdy construction of cob, especially if straw is added into the mix of clay and sand, can support an arch over an arched window that is otherwise standard window size or even double the width of a standard window in today's construction of houses. In several pictures of completed cob homes, arches across doorways that span twice the width of standard house door also appeared strong.

You can set the window or door temporarily in place, and pretty simply mold the cob around it and let dry.

A home in Niger, Africa.
A home in Niger, Africa. | Source

Cob House Plans

Several sets of plans and intructions I read suggested that the arch should be made more narrow in the center than on the ends, so that the weight the arch must bear can be somewhat reduced. No specific measurements were given.

None of the house plans indicated any means for determining the lengths of arches of any longer possible spans than a standard window, double window, door width, or double door width. However, since the cob-with-straw-mix is extremely strong when sun-baked, a longer arch span of this material may be possible. Based in standard engineering calculations, the base supporting the arch would need to be of a size, height, strength, and shape adequate to support the span of cob.

For longer cob arches, suspension bridge building engineering formulas would likely work, and your local university engineering and architecture departments would probably help you with these at no charge. Graduate students often do these sorts of projects and department professors check their work.

Cob Series

The Work of Freeman Yorde

Resource and Energy Efficient Living (REEL)

In Knox County, Freeman Yorde built himself a small house out of cob and recycled wood (for framing). A house of 336 square feet, it is built on a foundation of 12-by-24 feet.

Background

Mr. Yorde learned what he says is the "art" of cob construction in Portland, Oregon from Eric Hoel. Mr. Hoel went on to Baltimore, MD to work with Habitat for Humanity. Freeman helped eric build a house of 750 sq. ft. (or round foot, because the building's walls are curved) above a river in Salem, Oregon.

Freeman returned to Knox County in Central Ohio in September. 2002. There he found an interesting 10-day cob building workshop in southeastern Ohio at what he recalls to be named the Green Fire Ranch on SR 50 east of Athens. Ianto Evans, who had taught Freeman and his friend Eric how to build with cob techniques, ran the workshop. Freeman continued to live in Gambier for the year, working as a house framer for a company that had employed his father as a construction manager.

The following summer (2003), Freeman spent in Vermont. He returned to Gambier during Autumn 2003 and contacted a student group on the Kenyon College campus named Resource and Energy Efficient Living (REEL).

With REEL support, Freeman wrote a successful proposal to Kenyon College to rebuild the tool shed, which had once been a goat barn. His proposal included earthen and reclaimed materials, such as old barn beams and timbers. These were excellent ideas for sustainability.

Professor Ray Heithaus of the Kenyon biology department oversaw the BFEC and was the impetus toward success. The leaders of REEL, Prof. Heithaus, and Freeman met with Kenyon's Buildings and Grounds Superintendent and his assistant to establish a possible stipend for the building.

Actually, $3,000 was dedicated to the building, half for construction tools and materials and half for Freeman Yorde. Interestingly, at the same time, a $60,000,000 Kenyon Athletic Facility construction project had already been ongoing for a year. Kenyon officials must have considered the cob project important as well.

Kenyon Tool Shed Cob Project (2004 - 2006)

Construction on the cob tool shed in Knox County, Ohio began at the Brown Family Environmental Center (BFEC) at Kenyon College on March 31, 2004. Freeman Yorde graduated from that school in 1996 in Gambier, Ohio.

Construction on the cob shed lasted 3 building seasons, which adds up to 29 months from March, 2004 to October, 2006.

From the beginning, all work was accomplished by hand and foot, including digging, shoveling, hauling, mixing the cob, and building the wall. It took dedication and a lot of energy to complete the work.

Total cost of the building did not exceed $2,500 - excellent by construction standards. Over 200 sets of hands built the shed, using eight tons of clay, 12 tons of sand, hundreds of gallons of water, and 20 bales of straw to create earthen walls. No wonder it probably required centuries to build the pyramids of earthen bricks or stone in Egypt.

The doors to the shed were donated generously by friends. The transparent windows are from an old lake cabin in Northern Wisconsin and the stained glass windows were made by Freeman's sister-in-law in Chicago. The roof was donated by the company 64 Metals, Inc. in St. Louisville, Ohio.

Serendipity At the Tool Shed

Freeman Yorde met his future wife on this project. At the midpoint of the first building season (2004), the future Mrs. Yorde became Freeman's building partner.

The couple married in Columbus, Ohio at their church, Xenos Christian Fellowship, on May 29, 2010. In addition, Freeman reports that he came to know the Lord as a result of doing the tool shed project, becoming a Christian in Decemeber of 2004. He says that, "without God, this project never would have gotten finished."

This is all genuninely uplifting. Freeman Yorde learned sustainable building construction, met his future wife on a construction project, and found the Lord all in the same venue, whose main ingredient was the Earth used for contruction.

Life Lesson From the Shed

A meaningful quote from Freeman Yorde:

Machines are not the enemy ... and yet we cannot let what we do with our hands, the skill of our trade, be set aside to wither.

Freeman suggests the following site:

See www.cobcottage.com, maintained by Ianto Evans and his wife Linda Smiley.

Brown Family Environmental Center, Kenyon College

show route and directions
A markerKenyon College, Gambier OH -
Kenyon College, Gambier, OH 43022, USA
[get directions]

B markerBrown Family Environmental Center, 9781 Laymon Road, Gambier, Ohio 43022 -
9781 Laymon Road, Gambier, OH 43022, USA
[get directions]

Cob Workshops In the Midwest

Cob revivalist Ianto Evans gave a series of Cob Workshops at the Ohio State University in 2004. Evans helped attendees to refresh current skills and to learn new ones as well. One lesson taught was that a properly constructed and molded cob house can last for over 100 years.

Making Cob

Cob Architecture In America

  • Cob Projects - Timeless Art of Cob Building - hundreds of projects and fantastic photos.
  • cobworkshops.org lists many workshops featuring cob in North America.
  • coblist email discussion group about cob.
  • daycreek.com page of photos and description of cob.
  • housealive.org This site is mostly focused on cob, and offers information and workshops.
  • barefootbuilder.com has information about cob and sponsors cob workshops in Tennessee
  • cobbuildersforum.com - Forum specific to cob building; gallery, videos, and workshops listed.

Adobe in the American Southwest: Another Form of Cob

Source

© 2008 Patty Inglish

More by this Author


Please Add Comments & Alternative Building Links Here! 33 comments

Zsuzsy Bee profile image

Zsuzsy Bee 8 years ago from Ontario/Canada

Patty! I must look into this type of building. I could do that. I like it a lot. Research here we come.

Thanks for giving me a great idea.

awesome hub as always regards Zsuzsy


Bob Ewing profile image

Bob Ewing 8 years ago from New Brunswick

This is an excellent resource, thanks.


Rob Jundt profile image

Rob Jundt 8 years ago from Midwest USA

Fun hub. Great links. Thanks.


Eileen Hughes profile image

Eileen Hughes 8 years ago from Northam Western Australia

I saw an article on tv the other night where a house was built from polystyrene. Its amazing what can be done these days. Very interesting hub Thanks Patty


ahmu profile image

ahmu 8 years ago

nice hub u make i like it


Chef Jeff profile image

Chef Jeff 8 years ago from Universe, Milky Way, Outer Arm, Sol, Earth, Western Hemisphere, North America, Illinois, Chicago.

The first picture reminds me of the House of the Future they had at Disneyland back when I was a kid, with the rounded arch & smooth surfaces. I wonder how well this would go over with our local county building inspector folks, who seem to believe that a house can only be built of wood & plasterboard.

Great hub, and, I hope to read more about this and other construction topics.


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Thanks for all the comments! Just to clarify my sources --

I have a contact that is an archeologist working in Egypt - they have indeed found bricks in some pyramids made of mud, straw, sand and clay. Not molded like cob is molded - dried into large bricks, but still of the same materials.

Adobe - I have RN friends in New Mexico that state adobe in their locale is very much made like cob - no mortar.


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Chef Jeff! - I wonder also what the building inspectors would say. The house in Knox County Ohio passed OK. Counties across the nation are different about this, I'm sure.


C.S.Alexis profile image

C.S.Alexis 8 years ago from NW Indiana

Do love the simple and soft lines in these structures. They feel very warm and inviting.


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

I agree, CS Alexis, and they look strong and durable as well. Many people say they feel a definite good energy when they walk into these dwellings.


C.S.Alexis profile image

C.S.Alexis 8 years ago from NW Indiana

Patty, these structures almost invite you to move in ASAP! I know there is something to the flowing lines and the good energy, like waves of peace flowing in the wind. It is perfectly lovely, natural and elusive, sorta like following a winding river or road and you just keep going and you know in your heart that it will be right around the next bend, harmonious! Thank you for this hub. Nice!


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Hi CS Alexis - An associate and friend in Michigan own some property and I'm going to suggest they build at least one cob building on it.

There are some underground homes in Ohio and Michigan that have cob molded around the exposed entrances and skylights. I will attempt to get some pictures of these. In and around Dayton Ohio, there have been underground office buislings, with perhsps the front 25% of the building exposed to light and using solar panels, etc, Hills were built around them. Very low utilities bills.

I've read a few comments on diswcussion baords about cob houses being "toasty" and warm in the winter and cool without air conditioning in the summer, especiialy if shaded propery with trees, etc. I have the sense that soil-sand-clay-straw cob is warmer than sand-clay-adobe in the winter from all of these comments, but I don't know, myself. Then there are comments and pictures in the books on cob architecture that show how rock-hard the soil-based cob becomes in the sun - as hard as sandstone and some other rock. This could likely be sanded to smooth its rough surface.

At any rate, I think I want a cob home now, too.

Thanks so much for posting.


Garry Nelson profile image

Garry Nelson 8 years ago from Hawaii

Be sure and check out earthbag homes, like the honey house.


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author


dlarson profile image

dlarson 8 years ago from Priest River, ID

Wow, thanks for the reply Patty! We're going to build one of these ourselves but without building permits. They don't exactly comply with the IBC and here, if an inspector can't compare it to "the book", its not going to get approved.

Maybe I'll build a garden wall first and see just how large of an arch I can build with the stuff. Then I'll load it down after it dries and see how much weight it will carry....


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Hi dlarson! A garden wall sounds like a good first project. I hope you take pictures and do a hub of it so we can see!

I think you might try to reinforce the arch with something like chicken wire as a base, like build a framework and work the cob up around it and into it and pack it in tight. This is like putting a flat metal mesh base into a wall that needs new plastering.

If you can get the chickenwire mounted strongly into the ends of the opening for the arch, this might work wwell, and the chicken wire can be bent into a convex arch somewhat. Then, with an arch narrower slightly in the middle, you may have strength and a good looking arch. I surely hope so!

Patty


Nathan Brown 8 years ago

Here's a great cob house building work exchange opportunity for anyone who's interested: http://www.dancingrabbit.org/social_change/interns...

The guy running this is a friend of mine and I think he's great to work with.


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Wonderful, Nathan! Thanks for the link; people will enjoy it.


want2know 8 years ago

Cool hub I am sharing this hub with a friend whos a eco building consultant it has great insite and resources.

Thank you for the information


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Great want2know! Hope some of the resources really help.


blogit2050 profile image

blogit2050 8 years ago from india

Wow, kool piece of work and hard work...nice


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Thanks blogit2050! -- I'm still looking for pictures of cob bricks large enough for a pyramid. In northern Ohio, a couple people are using large cob bricks, so I will go up asap and photog them.


korey 8 years ago

someday i will build my own thank you


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

That's wonderful. Congratulations on your choice!


sherlynavia 8 years ago from United States

Great hub with good stuff!


Jan Mosbacher profile image

Jan Mosbacher 8 years ago from Devon

Hi Patty

Great photo's!

I used to live in a beautiful Devon Longhouse, where the cob walls were 300 years old. It's amazing to think that walls made of straw and mud can last so long, and they're so easy to repair if there ever is a problem.

Best wishes

Jan


Patty Inglish, MS profile image

Patty Inglish, MS 8 years ago from North America Author

Thanks very much for sharing that with us, Jan. We have lots of ready building material all around us, don't we?


Tatjana-Mihaela profile image

Tatjana-Mihaela 7 years ago from Zadar, CROATIA

Wow, Patty, this is great Hub. Especially for me, I have 5years experience in cobing, while renewing my 100 years old weekend house. Cobing is amazing, because you become one with the house you build, it is such a passion, you sculpt the wals, you can do whatever you want from mud. It is hard work, but soo funny. Very soon I will write a hub about it, in case you are interested, there is one picture of my living room in the hub "How to achieve good vitality & stay young, active, healthy!".

Many thanks for this Hub.

A lot of best wishes for Xmas and Happy New Year!


Patty Inglish, MS profile image

Patty Inglish, MS 7 years ago from North America Author

Tatjana-Mihalea -- I've joined your fan club to see more pictures like the one on your link. Of the people I know, those individuals and families that have built their own homes are happiest. Many of them have been cob buildings. They have shown my all sorts of structures, including cob "bricks" larger than myself. It is fascnating.


chloefaith profile image

chloefaith 7 years ago from White Sands Area

As a resident of New Mexico I am familiar with adobe housing. You made a nice presentation of it, funny how quickly we want to unload all that progress and revert into something easy and cheap. I am into the eco-friendly environment, but there are reasons for evolution. I love your hub.


Avare profile image

Avare 7 years ago

Great hub! Thanks for interesting reading. Rated it! :)


Patty Inglish, MS profile image

Patty Inglish, MS 7 years ago from North America Author

chloefaith - New Mexico is a gorgeous state and I've seen many pictures of the attractive cob buildings there. Easy and cheap as well as attractive and useful is the best!

Avare - thanks for commenting; glad you liked it.


LEEDap 7 years ago

cool cob structures! interesting info

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