This is how it began. Underneath the bales you can see some black plastic. This is covering a concrete footing/slab on which the bales rest.
Embedded in the slab are 7 star pickets. The bales of straw were then impaled on them.
The hollow in the centre of the bale base has been lined with plastic and filled with sand.
Reo mesh has then be tied on to the top of the pickets to provide strength to the slab that will be poured on top.
Form-work has then strapped around the base to allow for a 100mm concrete slab.
The mix for the slab includes perlite (instead of aggregate) to improve insulation.
Once the slab has set, and form work removed, two layers of 50mm thick pavers are laid on top.
Pavers are laid with the bevelled side facing down.
This gives the floor of the oven a nice smooth surface.
I worked out the center of the oven. Stuck down a washer and then started laying the first course of bricks.
I've used recycled red clay brick.
The first course has been laid standing up. This gives a bit of height to the cooking space.
I seem to remember reading somewhere that laying the first course this way is a Neapolitan style oven.
Here you can see the jig being used to place each half brick at the right angle to give a nice smooth and even dome.
I think that the next course became quite tricky. They didn't stay in place long enough to allow the mortar to grab and kept slipping off.
To finish the dome I created a platform on which a dome of sand could be molded.
To make it easy to clean up, I lined the floor of the oven with a tarp.
A bit of chipboard, propped up on some bricks created the platform.
Once the sand on top of the platform was molded into what looked like the right shape, the bricks where then set in place around the dome mold.
With the dome bricks locked in place, I waited for the mortar to set over night, then removed the platform and mold.
I ended up rendering the dome, mainly as a way of using up left over mortar. I think this helped to seal up any little cracks, and made it looked a bit tidier.
Being a pretty impatient bloke, I started firing the oven up straight away.
The processing of tempering the oven took about a week.
I lit a series of five fires leaving the oven to completely cool between each fire.
a handful of newspaper
newspaper with a bundle of kindling
a small fire with one substantial piece of wood
a med size fire with a few substantial pieces of wood
a large fire
This is how it ended up.
The dome has been covered in a layer of rockwool insulation, chicken wire, and a another coat of sand/cement render.
After two years of weathering and a fair bit of use, it's still in the same condition.
