reasons for cob

Resource Review –

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We’ve been looking into several resources on cob building and learning to build with cob, and one of the best resources we’ve found so far is Alex Sumerall’s We’ve read his book, signed up for his online cob building workshop, subscribed to his blog, and most recently, attended his free webinar, “Introduction to Cob Building”.

Alex has also been incredibly helpful in providing specific answers to questions we had on cob building. He’s responded to every email promptly and with great detail. It’s definitely a bonus having quick access to the author and teacher of the course!

Some of the free resources Alex offers are webinars, blog posts, and articles, as well as links to more information from other cob experts. However, if you’re ready to dig into (pun intended) more detail, he offers an intensive and in depth course on cob building that’s as close to a workshop as you can get without actually having to invest the time and money required to go to one (although he offers the workshops as well).

The course is presented in video format, a combination of footage from his build sites and PowerPoint presentations on more of the “classroom” type knowledge, and includes printable notes and a Q&A comment section for each lesson. It’s a 12-month course, although I believe only 5 months are up on the website right now, but that could be because we don’t have access to the later lessons yet. Each month is broken down into basically what you would be doing for that month on your own dig site, at least that’s how the first month has been for us. Alex includes case studies, monthly Q&A reviews, and instructions for different design options, including round and square foundations and walls.

He has two books, Build a Cob House: A Step-by-Step Guide, and Cob to Code, which covers building codes and their impact on cob housing. The first book breaks everything down, truly step by step, with instructions and photos of each part of the building process. The second book I have yet to read, mostly because building codes don’t apply in our area.

Casey and I both attended the free webinar today, and I really hope Alex plans on hosting more of these! It was informative and included a Q&A at the end. Unfortunately, Alex received so many questions that he wasn’t able to answer the several I submitted before the end of the webinar. I sent him a quick email, and once I’ve received the answers, I’ll update this post to include them.

UPDATE: Just seconds after I finished this, I received a response from Alex. Thanks for the quick reply!

Q: I’ve read in your book and Becky Bee’s book that you shouldn’t use hay, but instead use straw. However, Bee also mentioned that many local grasses and reeds can be used. Isn’t hay a type of grass? And if used and it does sprout, can you just let it sprout and pluck it before plastering? We don’t have good sources of straw in SE Oklahoma, but we have tons of hay!
A:  Yes, you could let the hay sprout and then just go from there. Straw is always best if you can get some though. It has stronger tensile strength.

Hay is a pre-harvest crop. Straw is post harvest, and doesn’t have the living organic parts left that can easily decay.

Q:  Can you use cob for roofs?

A:  Cob can’t be used for roofs since it’s too heavy. The only way to use earth materials for a roof is to do a dome or vault using either adobe blocks or superadobe, but these are quite technical to construct.

Q:  Can you use cob for tubs or sinks?

A:  You can sculpt cob sinks, tubs, showers and then plaster them with a lime render called tadelakt. It is waterproof.

Q:  [Regarding a special Alex ran during the webinar] Can we get the cob plans even though we’ve already registered for your course?

A:  And yes, I’ll attach the plans for you too!

So if you’re looking for more information on building with cob, check out And the special Alex is running includes both of his books and two sets of cob building plans, one for a house and one for a garden wall. It’s a great value, all included in the current subscription price for the online course.

Have you found any great resources you’d like us to mention or review in upcoming posts? Add them in the comments below, and we’ll be sure to check them out!


Deciding to Build with Cob, or Explaining to My Mother* Why I Want to Live in a Mud Hut

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We are not outdoorsy people. We are geeks. By we, I mean me, my husband Casey, and our 12-year-old daughter Lili. We like LOTR, Game of Thrones, D&D, Big Bang Theory, Legos, dragons, reading Star Trek novels on our Kindle (unlimited membership, of course), and debating on the best OS (Linux and Android, duh).

We are not outdoorsy people. We have allergies to pollen, cedar, hay, and numerous other things. We think 68 degrees is a “smidge chilly” and 74 degrees is “way too freakin’ hot” to go outside. We are out of shape, easily fatigued, and drink too much caffeine.

So why on earth would we want to build our own home? Out of dirt? With nothing fancier than a shovel and a level? Out of dirt? Outside? By ourselves? Outside? With no knowledge of construction or engineering beyond the scope of the aforementioned Legos? Out of dirt?

For every reason mentioned above, and so much more. We are out of shape geeks who need a lifestyle change. We need simplification, a route to common sense financial independence, and a return to good health and living in tune with the land. We need an extreme nerd makeover.

Casey and I (and to a lesser enthusiastic sense, Lili) have been exploring the idea of “alternative” housing and energy for a couple of years now. We decided last year we wanted to build tiny. We also saw that even in tiny housing, the costs and impact on the environment  can be large if you outsource materials that are not local and have others do your building.

So then our thoughts turned to, “Could we really do this ourselves? And how inexpensive (cheap) could we make it?”

And then a few months ago while reading before bedtime, something we normally try to do to wind down, Casey came across a chapter in a tiny house book on cob houses. Now given, Casey had just taken his back pain medicine and was a little loopy. He started rambling about wanting to live in a mud hut, and spent the next 2 hours boring me with this idea of cob housing, until finally I told him to just go to sleep, and not very politely.

Then I spent the next 2 hours thinking about this idea of cob housing and did a little research on my phone and thinking and not getting my brain to shut up. The next day I told Casey I thought the idea of cob housing was brilliant, to which he replied with a bewildered look, “Cob housing? What’s that?”

After I explained to him what he had oh-so-eloquently slurred to me the night before (those are some good pain meds), he thought it was a great idea too. Leave it to Casey to come up with a good housing option while doped up on medication.

Here’s the rundown on why we chose cob:

1) Much of the building material comes right out of the ground you are building on (can’t get much more local than that). The rest of it is either free or nearly free, and can usually be found locally.

2) Although pretty labor intensive, it is relatively easy to build, requiring no special skills or equipment.

3) It’s labor intensive, so it’ll get us into shape.

4) Did I mention how cheap it is?

5) Two-thirds of the world live in earthen housing of some type, and have for centuries.

6) Cob housing can last hundreds, if not thousands of years.

7) It brings us back to our roots, both Choctaw, who lived in wattle and daub housing, which is like cob with sticks, and European, who built with traditional cob and thatched roofs.

8) Cob housing can be beautiful. There is no mistaking the finished product for a mud hut.

9) The materials are all natural, and less likely to cause health issues, in comparison to the chemical laden commercially available materials.

10) We get to build and design and literally shape our house with our own hands, being as creative and geeky as we want. (Can we say cob dragon pizza oven?) And since cob lends itself so well to natural curves and out-of-the-box shapes, I’ve already picked out my hobbit door.

So, no, Mama, I will not be living in a mud hut. I will have electricity (wind-powered, most likely), running water (but not to the toilet, as there are much better options than wasting fresh drinking water on doing your business), and all the comforts of a modern home, without the need for central heat and air thanks to passive solar design.

Progress Update:  We broke ground last Sunday on our new home site. We’ve almost cleared the site of grass. We’ve designed the floor plan and are working on a miniature clay model of the house to get an idea of wall and furniture dimensions. We’ve done some testing of soil samples and hauled in some urbanite and gravel from a local construction site (all for free). See pics below. Top: Casey staking out our floor plan to get an idea of the space. Middle: Jenny (our dog, the perfect size for a tiny house) checking out the first day of digging. Bottom:  Our jar of soil sample using the shake test. It’s hard to tell, but there are 3 separate layers: a chunky river sand, roughly 60%; silt, 20%; clay, 20%. This is probably an okay ratio, but we’ll do a lot more testing to make sure we don’t need to add more sand (easy to get in this area) or more clay (not sure yet on a source for this, so we may need to harvest clay from another part of the land by doing large-scale shake tests and scraping off the clay). Once we get more subsoil dug out, we’ll be able to run more tests with straw to make sure.

Casey staking out foundation First day of digging Shake Soil Test in Jar

Money Spent:  $4 for twine and $11 for tent stakes to map out the footprint on the ground

Total Cost to Date: $15

*Once I explained the idea to her, my mother is actually very supportive of this plan. She’s all about living green and values the artistic but low environmental impact that cob housing can have on the land. Props to my Mama for teaching me how to save money, reuse, reduce, and recycle!