Want to continue building an earth oven with the lovely people at Saffron Acres? (next session Saturday 14th June – are you available?)
LESSBIG is ‘on site’ and needs your help!
Previously, on LESSBIG…
What on earth is this supposed to be? (pun very much intended)
On a really nice Saturday, seven of us got started at about 11am.
Digging and mixing
Plenty of digging to do.
Loading up the wheelbarrows
First we mixed and trod in the wheelbarrows…
…but a plastic sheet on the ground is probably better.
Using various cut log sizes to help build up the base. (see – cordwood or stackwall construction)
Making a “demo dome”
At this stage, with maybe 2/3rds of the base complete we then focused on making a demo dome:
Testing out the method for building a dome. This dome of sand was approximately half as high as it was wide.
Wet newspaper layer to help when digging the sand back out.
The first rough layer. We tried to use a finer mix of woodchip in this mix. Remember to try and press more down rather than in when building up.
The second layer was more liquid and smooth which helps seal the gaps, obviously important for insulation but also looks a bit tidier.
Cutting out the door with a small pointed trowel. Kiko Denzers book, I believe, suggests the door should be just over half/60% the height of the dome.
Scoop out the sand.
A bit of tinder
Nothing like burning things at the end of a long day. (Note in the background we covered the other one over with plastic sheet)
The little chimney hole with smoke, using a bit of log as a door. The earth is still wet of course, but you can just about understand the principle of absorbing lots of heat and radiating out afterwards. With this mini version, the walls might be too thin for it to really work. Also the concrete slab base won’t be as insulated as the real one. Still, I should give it a try when it’s properly dry.
The next week…
I came back after a couple of days to carry on. The base is nearly at the height I was aiming for the entrance (see the beanpole to the side); so you don’t have to bend down so much when using the oven.
There had been a day in between visits where it had rained, so I was pleased to see these test pieces (left uncovered) seemed to be okay. To be fair, it wasn’t much rain, the next time I visit I bet they will just be sad little heaps of mud. Fingers crossed anyway.
So after about 4 hours by myself, I think I’ve gotten to the level where we will put a glass bottle layer in, then the base, then the dome itself. (nb- thanks to everyone for bringing down some empty bottles!)
For reference, I would say with these two stages combined, plus general faffing around and the foundation, it would take one person about 30 hours to get this far. So still probably feasible, over enough time for a single person to take on if you’re looking for a summer project for the garden. An awful lot of that time is just digging and mixing; but then you are doing the manufacturing (ie making everything from scratch), as well as the construction (ie not using ready made bricks or blocks.).
Get in touch (rfletcher@dmu.ac.uk ) if you want to help out with the next stage on the 14th of June, when we will probably be able to finish it off and give it a test fire at least.
For those of you who don’t know where Saffron Acres is, it is fairly central, on Coppinger Road, just off Saffron Road. Near the Aylestone Leisure Centre. If you don’t fancy the oven, they’ve got tons of other stuff you could get involved in!
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