Lammas Part Four - A Greenhouse Made of Mud

The cob greenhouses which Nigel and Cassie had constructed were both charming and functional. Of course they had glass in too, for solid mud does not make for a good greenhouse. But the glass frames were encased in cob and the back wall was entirely made of cordwood and cob. The overall effect was of a light, warm growing environment, but one where the natural properties of the cob regulated the environment, stopping it from overheating during the day and releasing its stored warmth during the night.
Inside there were grapes and peaches, tomatoes and peppers as well as medicinal plants, for Cassie is a herbalist too.
One had a hügelkultur bed - a permaculture system where a growing bed is started off with logs, sticks and brushwood before being covered with layers variously of manure, rotting grass, straw and soil. It is supposed to provide long term fertility and a rich, living soil. It is an idea which I intend to try out in my veg plot.

Two sections of the greenhouse were already built. We were completing the structure. On the other end of the greenhouse was a cob room which had been given over to Cassie's daughter. What a wonderful space for a teenager.
I worked initially on the back wall which was not quite so straightforward as it seemed, having a bit of a lean and a bend going on. We were working on ladder staging with one person on each side of the wall.



Meanwhile others were working on the fill in between the window frames. This was the slow bit as there was not space for cordwood. The cob was sagging too, so we added straw to give it more structure. There was lots of banging in of nails too, known as spragging. These nails give the cob something to key into and hang on to.




Progress on the first day was slow. It was day four before we came back to the greenhouse with a determination to make faster progress. The A-team were on the job today! Progress around the window frames and over the top was faster. We were going through cob mix like nobody's business. There were occasional deviations for creative sculpture in the walls. There were troll-like faces, fertility symbols, a lizard and, of course, a cob-web.

















A cob greenhouse would be lovely back at Swallow Farm, but it is a huge project and one which I am not sure will ever happen. We'll see.
Maybe if the cob was mixed by animals and I had a team of volunteers to help out...

Lammas Part Three - The Cob Nuts get to work

Tuesday saw us cob building in earnest. There was a cob greenhouse to work on and a timber frame building known as an Eco-pod.
The walls were made of cob, which is a mix of clay and sand. Often straw is added to give it strength. For the Eco-pod we were adding small amounts of lime. This helps to stabilise the cob, making it more weather-resistant, and also inhibits any fungal growth on the straw of the wood.

Chopping wood for the cordwood walls

The team making progress on the cordwood wall of the Ecopod

Both buildings were using cord wood as well as cob. Basically logs are placed across the wall and sandwiched together with cob. This means that faster progress can be made and a lot less cob is needed. For what I haven't yet told you about cob is that it is by far best to mix it with your feet!
It is hard work.

Traditionally it may well have been mixed by placing animals in enclosures filled with the mix ingredients. A little dung does no harm to the cob.

We only mixed one batch from scratch, taking the subsoil from existing heaps and adding in bought in clay. Where we live it would be the other way round, as our clay would need the addition of sand.

Mixing a clay 'slip' to be added to the subsoil

For the other batches, we were recycling a couple of old cob walls which had not fared well.
Cassie has learned about cob the hard way, by trying different mixes. Even if it has been built by volunteers, it must be desperately sad when all that hard work crumbles within a few years. One of the walls had apparently been mixed by digger, a short-cut too far, and one had been too thick at the base.
Personally I would rather do thorough research and learn by other people's mistakes, especially when so much hard work is involved.

I worked on the greenhouse that first day. Progress was very slow, especially round the window frames where we were using pure cob without the cordwood. The cob would do its best to sag too, so it was only really possible to build up about a foot at a time before leaving it overnight to settle.

While we were beavering away, we learned more about the community. It had been a difficult year with someone's house burning down (three years of hard work and commitment down the drain) followed by the drought.
But it did not sound as if the community was pulling together well either. There were hints at problems in committee (the usual story), obstinate individuals and those who just wanted to get on with things in isolation. This surprised me. The Ecovillage seemed more like nine disparate smallholdings. Yes, each smallholding was probably fulfilling the dreams of its occupants, but the community aspect seemed sadly lacking.
The same problems as afflict wider society seemed prevalent here too. This was a crying shame, as you would think that nine families with so much in common and such a similar set of beliefs and principles could be so much stronger than the sum of their parts.

More on the Lammas EcoVillage, how it started and how it works, in an upcoming post. More on the cob greenhouse idea too.

Lammas Part Two - A Gang Comes Together In The EcoVillage Hub

So, just to get a few things straight from the last post.
Much of the stuff about the hub kitchen, cooking and washing up for yourself etc, was due to an imminent inspection from a health official. While there was absolutely nothing wrong with the kitchen, you can imagine that a shared kitchen in an eco-village and a health inspector might not be a good mix.

Our host, Cassandra, quickly became Cassie. She was a warm, strong, knowledgeable and committed person, whose environmental principles were second to none. Cassie and her family shared their smallholding with us for five days.

The most notable element of this smallholding was the many low-impact buildings. Most were based on round timbers harvested from a patch of old spruce woodland. The roundhouses  (technical term: Reciprocal Roof Roundhouses) were amazing, either for human occupation, for animal shelter or for outdoor human shelters.

This delightful roundhouse is the family home until the proper ne is constructed. 

Something tells me that Cassie and Nigel are pretty happy in here though.

Reciprocal Roof Roundhouse constructed as an animal shelter.

You can see the slate foundation wall and the cordwood and cob walls.

Likewise the cob greenhouses, one of which was to be our main project for the week.

Before I talk about cob, a step back to our arrival at Lammas on the Monday. We weren't starting till 3pm, with a tour around and an explanation of hub kitchen rules (due to imminent health inspection as I found out).
I had been all ready to get going at 9 in the morning, but the pace of life here was slower. Instead Sue and I went into Aberteifi (Cardigan) for provisions before visiting a local waterfall.

By quarter to three there were only a few of us hanging around in the hub building, despite the rest needing to arrive and set up tents before we started. 

Gradually our fellow course participants and comrades for the week turned up. Three had plush camper vans, one other like us was using Air BnB. The last to arrive came at 3.30pm and proclaimed that they knew it would be ok to be late as 'these places are always disorganised'!!!! The fact that we were sat waiting for them seemed to go unnoticed.

The wonderful Hub, built to be the centre of the community

Everybody was very friendly though and from all walks of life. After the tour, Sue and I headed back to our studio cottage, not envying those who would be spending a week cob building (basically playing with mud) and trying to stay clean in a bucket shower with the hot water being heated on a gas ring.
Overall though, facilities were good.
Fresh spring water was in short supply and this in turn meant that there was no electricity. The recent drought, which has been exceptional but may well become a more regular pattern, had meant that the community's main source of electricity, a hydro scheme, was struggling.
I was surprised that there were not more back-up systems in place.

All in all though, I was warming to the place. Things may be a little disorganised, but maybe it is my fault for not being able to deal with that?

Cob oven. Part Two.

Day 2 of the cob building weekend.

All twelve members of the Veg Group turned up last night and our gathering went on until quite late into the evening. But I was up before the sun as temperatures again sunk below freezing overnight and there was more rotavating to be done.

I managed to get an hour done before the soil started clogging in the tines of the rotavator.
At least there'll be plenty of clay in the soil when I decide to make my own cob structures on the smallholding.

We turned up at the Green Backyard only to be involved straight away in a hunt for a lost wedding ring. The guy had taken his ring off the day before and put it in his pocket. You can guess the rest. We didn't really know him well enough to joke, but mention was made that maybe it was embedded into the walls of the oven! Anyway, we explained about washing machine filters and sent him home to explore. We set to work mixing more cob. Today the cob was to contain straw, which is more normal. This gives it strength but it meant that we had to stomp and twist and stamp and dance even more to incorporate it into the cob.

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The outer layer of cob on the oven was made thick, very thick. On the plus side, the oven will be well insulated and retain its heat. On the other hand it meant that we had a lot of cob to make. I danced more today than I have in the past twenty years!

After yesterday's painful lesson, I wore gloves today to pack the cob onto the oven. It took five barrowloads of cob in the end and we didn't get it finished until gone 3 in the afternoon. A communal meal of soup and bread was much needed and much appreciated.

 

 

The oven still has one more layer to go, but this will have to wait a while now. It will be a fine layer of cob, containing cut straw, more as a decorative layer than anything else.

 

Oh. The wedding ring. Well I'm happy to say it was retrieved from the rubber seal of the washing machine, unscathed.

Dancing the cob stomp. Building a cob oven. Part One.

The Green Backyard
An amazing project which brings together community, art, sustainability and self-sufficiency

This past weekend we were booked onto a cob building course at the Green Backyard in Peterborough.
Before I talk about cob, a word or two about the Green Backyard. I have been there a couple of times before and really could not imagine a more welcoming place. It is a community garden right in the middle of Peterborough run along green principles, recycling, sustainability, creativity etc...
There always seem to be people popping in and something going on.

At the moment this precious project is unfortunately under threat. After 6 years of hard work, in which time their achievements have been amazing, there is a threat from the council to sell off the land to developers. Peterborough calls itself an Environmental City, so it is difficult to see how this can square up.

If you'd like to find out more, or support the GBY in their bid to buy the plot of land they sit on, please visit their website here.


So, back to the cob course. It was to be a busy weekend, starting with Blokes Baking (Shortbread and Doughnuts) on Friday evening. Another sharp frost predicted for Saturday morning meant that I was keen to get out for an hour or so with the rotavator. This is the only time I can easily turn the soil surface at this time of year.

Then we were booked on the cob building weekend from 11 a.m. followed by a dozen people coming round for the Smallholders Veg Growers Group which I was hosting in the evening.

We turned up to find that about 20 people were already there, all warmly wrapped up ready for a hard day's work (and socialising and learning).
Alan was our very expert leader for the weekend. He is based in Sherwood Forest and has spent many years working on sustainable building, green woodworking, woodland management, blacksmithing, charcoal kilning... basically, all the stuff I wish I'd got into many years ago.

Alan is well into double figures in building cob ovens. After a little background information, he led us outside where we all started demolishing an old strawberry patch. The idea was to clear away the topsoil in order to get at the clay/silt/sandy mix that is the subsoil.
This was to be our raw material for making cob.

Now that I think about it there are many meanings of the word cob. Loaves, webs, swans, nuts, corn, a sulk... All of these and more. But the sort of cob I'm talking about is the building material, made by mixing clay soil, sand and straw. It is much like the adobe walls I have seen in many tropical countries.

Today we were to be building a cob oven, but I have my mind set on using this building method to construct a new pig house and maybe as low dividing walls to divide up the chicken pen.

It's amazing how quickly 20 people can dig a big hole in the ground. It turns out this was the easy bit! Fortunately the subsoil had just the right mix of clay and sand, so we could work with what we dug, unadulterated. For the first layer of the oven there would be no straw mixed in. These fires can easily reach several hundred degrees centigrade, so the straw would not last too long and would just burn away to leave holes in the cob which would weaken it.

So we barrowed the subsoil onto a large tarpaulin, mixed in a little water and started stomping the cob dance! It's quite a simple process really, just stomping and jumping and twisting on the soil until it mixes. Roll it up and over in the tarpaulin and repeat...and repeat...and repeat...

Eventually you end up with your building material. After carefully shaping an igloo mould out of sand, we started the task of building up the first layer of the clay oven.


Alan explains to us
where the oven will sit

We gave the sand igloo
a coat of newspaper

For the future, it was maybe not the best idea to choose such a cold day for this. Shaping 'bricks' out of wet clay with your bare hands sucks the heat out of them very efficiently. My palms were caked in mud but the back of my hands was blue!

At that very moment the call went out that pizzas were now ready to be made on the rocket stove. I dipped my hands into a water butt, breaking the ice as I did so. My hands STUNG! They really STUNG! But the clay took some washing off and was I glad to find a slightly less cold bowl of water waiting over in the outdoor cooking area.
Anything hot would have tasted good right there and then, but the pizza which Sue had knocked up was especially delicious.

I retired inside for a while and took the chance to have a chat with a few of the Green Backyard regulars and to pick Alan's brains a little more. When I finally emerged, the rest of the group were just putting the finishing touches to the first clay layer.

The completed first layer,
artistically scored as a key for the next layer

It was time to bid our farewells for the day. Sue and I had really enjoyed ourselves. Hard work, fresh air, a bunch of like-minded people and learning a new skill had made for a very, very good day.

By the time we got home and sorted out the chickens, it was five o'clock. I was pleasantly shattered and had one hour to veg out before the Veg Group started arriving. More on that later.