Building a Cob Privy: Cobbing as Therapy

I’ve been shy about sharing my projects on here, in part because I’m in awe of what others have accomplished. But I’ve come to the conclusion that it might be inspiring to see a project by a less experienced, less talented person.

First, I thought I’d share how I came to natural building and to this site.

In February, 2013, my two young kids and I followed my wife to Kaolack, Senegal where she had gotten her dream job. In less than a month, I caught a virus that put me in the hospital for a week. Shortly after my mom was diagnosed with terminal cancer and died a month later. Over the next year, I grew weaker and my symptoms multiplied (at one point I listed them, covering over a page). I was dizzy, weak, exhausted, in pain, anxious, and depressed. In August, 2014, I had to ask my wife to leave her dream job and return to the United States.

While in Senegal we visited amazing examples of earthen buildings. I was not in a mind-space to appreciate or understand them, but they lodged in my imagination. When we returned to the US and I began to recover, we decided to buy land in Southern Utah where we would build with earth. We attended a cob workshop in Kentucky and visited Ianto and Linda’s Cob Cottage Company.

In 2016, I began my first big(ish) project: building a cob privy. This project and others have been my physical and emotional therapy for the past eight years.

In this thread, I’ll document the progress of that first project.

Thanks for reading!

From my building journal (6/15/2016):

"Spent morning laying out privy area, sat on 5 gallon bucket and speculated a while on the view and the layout. Staked it out, making it an oblong circle, then staked out the outer perimeter a knuckle fore-arm wider than the inner. Stringed it."

At this time, I had anxiety and was sleeping poorly, often waking up with a panic attack which triggered a migraine. Or maybe the migraine triggered the panic attack--I could never tell. The night of June 10, 2016, the wind was blowing hard making the Springbar tent's poles squeak. The Springbar was almost 50 years old, and my family camped in it before I was even born. We called it the hotel because my parents were too cheap to pay for an actual hotel. At 4 am, I woke to hear groaning right outside the tent. I jumped out of my sleeping bag in one motion, unzipped the door, and burst out ready to fight whoever was moaning outside my tent. Six feet away was a cow and a calf munching the sparse grass. My heartrate went down, and I managed to sleep a good hour past sunup.

That day I set to work completing a shed to store my tools. I'd stashed tools on a previous trip, and they'd been stolen. The guy at the hardware store in town said, "The way I've always figured it, a lock keeps an honest man honest."

That night, despite the wind threatening to blow the hotel down, I slept better than I had in months.

I'd decided from the beginning that I wanted the shape to be organic. I didn't want it perfectly round and certainly not square. What I love about Cob is the uncontrived shapes it lends itself to. I wanted the privy to feel as though it were shaped by nature. I wanted it to echo the Straight Cliffs in the distance. Ever since I'd hit bottom with my illness and depression, I was looking to rediscover beauty in the world. So I watched the land and looked to the horizon. From my journal (2/15/2016): "The more I look at the Straight Cliffs, the more I like them. It's like getting to know the face of a new love. I notice new things, like the small bits of pink, the horizontal stripe of white, the way trees dot the cliffs foot to top, even in places where the cliff's near vertical"

After staking out where the cob wall would sit, I began digging it out. The first three inches were easy, but then I hit hard-packed clay-rich earth. That was a good sign for making cob, but not so good for my back. I promised myself I’d buy a heavy duty hoe next chance I got. In the meanwhile, I chipped away with my spade and square point shovels.

Later, I wandered the property gathering the flattest, most even rocks I could find for the stem wall.

I gathered rocks for the stem wall and quickly found that I needed a lot of stones. It took a while to find enough flat-ish ones on our land. I couldn't find any gravel on the property, so I hired a local guy to bring a truckload of road base. I then sifted the gravel out, and put that in the area I'd dug out, tamping it well.

I'd only tried dry-stacking once before this. We'd visited the Cob Cottage Company, and I helped Ianto build the stem wall for a garden wall. We'd used urbanite, so we were guaranteed to have at least one flat surface. It was fun, like a jigsaw puzzle, but I wasn't adept at it. Ianto said he'd met people who were born with an eye for stacking stone, but most people only learn it through practice. I don't have an eye for it.

The most important principle I learned from Ianto is to make sure that every stone has at least three points of contact when you place it. The process was slow and tedious, and I quickly realized that I still didn't have enough stones. I'd exhausted the easy ones to find, and I had to search further afield.

In keeping with my philosophy of letting the shape of the privy be organic, I let the shape of my stones dictate the footprint.

Now the cobbing began. I'd always prided myself on my endurance, but the illness I got in Senegal had sapped that away. I needed to rest more than I would have liked. But somehow, my excitement for cob leant me stamina, and I put in long days.

On the third course of cob, I put in the bench for the toilet seat using salvaged boards from an old bookshelf. Up until this point, I'd been using a five gallon bucket fitted with a toilet seat hidden behind some cedar trees. I look forward to having a place to go.

The next course of cob incorporated a dry sink. A little more cobbing, and that would do it for the first year.

I'd grappled with some demons while building and camping on the land that first summer. The demons weren't beat yet, but they'd lost some strength.

The goal for my second summer was to finish the walls. My mother-in-law came for a visit from France and we brought her down to the land. She was interested in cob because there's a long tradition where she's from in Provence of earthen building, pisé . We spent the morning mixing up a batch of cob and putting a lift on the wall.

Looking good, Randy. I really like that one layer that dried lighter than the others...it gives it a sedimentary banding effect that blends with the landscape (of course when you plaster it that will be hidden, but it's still cool).

Reluctantly, I reached the conclusion that I neededto find a better way to mix cob, a faster way. As much as I like doing the cob dance, it was exhausting and slow. I’d thought about using a skid-steer, which is supposed to work well. But a Bobcat is expensive. And if I went that route, it would be hell on the land wherever I put the mixing area. I’d come across mentions of using a rototiller, and I decided I’d look into it.

I searched the Internet for rototiller and cob building. There were two YouTube videos, a couple minutes each. From what I could see, everybody was using small front-tine tillers. The downsides they talked about were rocks getting stuck in the tines and the straw getting chopped up. One even mentioned having to mix in the straw by foot, which defeats the purpose. From the videos, the problem I saw was that the rototiller did a good job mixing the clay, sand, and water together, but it didn’t compact the mix at all. And compacting strikes me as one of the most crucial parts of making good cob. The more I thought about it, the more I was convinced that what you needed was a big rototiller. One that would have the power to cut through the hard, dry clay. One with big enough tines not to get hung up on small rocks. One with the weight to compact the cob.

I went to the online classifieds and found a second-hand Troy-Bilt Horse. Reviews of the Horse say this is the gold-standard for rototillers. It’s designed for big gardens, up to an acre in size. It  has wide tires, weighs in at two hundred fifty pounds, has two speeds, goes in reverse, and has adjustable depth. I decided it would serve my purpose.

Here's a Permies thread on Rototiller Cob.

The other thing I needed was water. I needed to bring enough water to last me a week, especially if the rototiller would help me make as much cob as I hoped it would. I found a 275 gallon water tote in the classifieds.

I laid out a runway for the rototiller cob four meters long, digging down just to the hard-pack. I started by running the Horse through dry ingredients, but that didn’t work so well. It worked much better with water. I tried different techniques: running it forward and then throwing it in reverse; running it in circles letting the wheels spin in place; running it forward, making a U-turn, and running it through again. The latter-most technique worked best. With enough water mixed in, I threw in the straw and ran the Horse through again.

The first batch wasn’t as good as foot-cob. I couldn’t control the mix as well because clay from the runway got pulled in. And it used more water because without a tarp the ground soaked up some. The straw got chopped up a bit, but not so bad. I’d kept this mix small to get the hang of it. All in all, I was happy with the system. And I was sure I was right about the weight of the Horse being an asset. The biggest down-side was the noise.

My second batch was bigger: two wheelbarrows of road base for aggregate and four of earth for clay. It took me about an hour. The mix wasn’t perfect—some parts ended up wetter than others—but not bad. By my third batch, I felt like I had the technique dialed in. One thing that helped a lot was to soak the straw and dump the whole thing, water and all, once the sand, earth, and water was mixed well enough.

Where before, I’d have to mix at least three batches by foot, I could do one batch of roto-cob that lasted the day. Maneuvering the Horse was hard physical work, but it was worth the time savings.

My next task was to install the window. I scavenged the glass top to a round coffee table my neighbor put in the trash. I stenciled its outline on a piece of OSB and cut it out. I used the OSB as a proxy so I wouldn't break the glass. Once the cob was high enough, I removed the proxy and installed the glass. The idea was to frame a view of the Straight Cliffs. I tilted it at an angle to fit the way you'd look up while sitting on the pot.

I also installed a blue gin bottle as a small window to catch the morning light from the east.

I could only get down to the land for a week here and there, but I made good progress in 2017. Each time I went, I felt more at peace when I returned to the stresses of life back home.

I put in the windows, got the walls nearly to full height, installed the door lintel, and framed one side of the door. I put up temporary roof beams, so I could cover the privy with a tarp.

[I meant to continue this thread sooner, but the summer got really busy.]

The next summer, I began working on the roof. I struggled for a long time figuring out what kind of roof I wanted. I'd gotten the same advice from both Ianto Evans and my dad: delay making decisions until you have to. Well, now I had to. I considered and rejected the obvious approaches.

*My wife's first choice was a living roof, but that wasn't really an option in the desert, where plants have incredibly deep roots in order to find water.
*I like the Ancestral Puebloan method of having large beams topped by a lattice of willow branches and covered in earth. But I didn't trust my ability to make such a structure that would drain properly and wouldn't leak.
*A traditional roof sheathed in boards and topped with shingles wasn't an option for both aesthetic reasons and practical reasons, i.e., the shape of the building.
*A metal roof was an option, but I didn't like it on aesthetic grounds.

After searching the Permies.com forums, I stumbled on Vela Creations' approach to making latex concrete roofs (https://velacreations.com/howto/latex-concrete-roof/). I was hesitant to use concrete, but in the end I decided it was the best approach.

I knew I wanted exposed roundwood beams (vigas) that you could see from the inside and outside, so I started there.

I had a couple long pine logs, but they'd been on the ground too long and had gotten punky at the ends. I managed to salvage one, but it was only long enough to cover the building along the side, not the center. I had a similar sized cedar log that I harvested on the land from a standing dead tree. I searched the land for a log long enough to span the center. We have two types of trees: cedar (juniper) and pinyon. The cedars are really strong, but they tend to be short and they taper quickly. The pinyons are taller and more slender, but they're weaker.

I searched and searched and I finally found an old log I that was plenty long. It was thinner than I'd wanted and it had a major twist to it, so I initially dismissed it. I kept returning to it, though. I tested its strength by propping it up and jumping on it and found it didn't give at all. It was well seasoned, no bark, and I think it had been the root of a pinyon.

It struck me as a little funny to have these three different types of wood as the roof beams, but I felt it was also appropriate, as they came from trees indigenous to the area (the pine log wasn't from our land, but probably from the higher altitude forests nearby--I'm not really sure of its provenance).

The middle log was a little tricky to get placed because of the twist. I tried different orientations, but it kept rolling back to the same position. I decided to stop fighting it and go with it. I tied the three beams in place with baling wire attached to the deadmen below, and I cobbed a cradle around the base of each one.

Gratuitous rainbow pictures:

My next step was to work on the ceiling. I wanted the beams visible on the inside, and I wanted an earthen ceiling. In the course of whiling away time on YouTube watching cob porn, I saw some people making exactly the ceiling I wanted. They stapled hardware cloth over the beams and then covered the top with a thin layer of cob pancakes.

I covered the roof with hardware cloth and trimmed it to fit. I then cobbed around the wall until it was level with the roof beams and incorporated the edges of the hardware cloth. I let it stiffen and then covered the top in a thin layer of cob. The weight of the cob made it penetrate a little way through the mesh. Later I would plaster from below, which would serve simultaneously an aesthetic purpose and a structural purpose in locking the hardware cloth in the middle.

By the time I finished the roof, I'd gotten back most of my strength and I was able to deal better with my anxiety. I continued to suffer regular migraines, but they rarely came when I was on the land building. I credit this project with helping me to rebuild myself mentally and physically.

I put cardboard, tarp, screen, and latex concrete on top of the beams, cob, and rafters to form the roof.

My dad built a cabin by hand, and, as he says, you never really finish a project like this. But I called it finished in 2020 once I'd plastered the ceiling and walls and had made an earthen floor. I'm unduly proud of my privy despite its flaws and the time it took me. By the time I finished, I felt like I was back to my old self. I'd rebuilt my strength and endurance. My migraines were manageable. And my mood had lifted.

Thanks for sharing your journey with your cob privy as well as your health.  We are planning a similar thing on our land, and I am dealing with a similar physical journey as well, so I found it interesting, inspiring and useful.  Thanks for taking the time to share it.

Barb Allen wrote:Thanks for sharing your journey with your cob privy as well as your health.  We are planning a similar thing on our land, and I am dealing with a similar physical journey as well, so I found it interesting, inspiring and useful.  Thanks for taking the time to share it.

Thanks, Barb. Let me know how things go for you.

Your journey was inspiring to me, Randy.  Appreciate your sharing.  

Thank you for sharing your journey and detailing all your building steps. Congratulations on finishing this project.