Dave's barrel build, Shoreham By Sea.

[davenott]

I wanted to build a small pizza oven, then decided I wanted to bake bread in it too.
My 8 year old son then asked if I could build one big enough to cook a small pig, after a little thought, I decided to change my initial design to a barrel oven.
I bought 2 books; The Bread Builders, and From the Wood-Fired Oven, and also read up on as many builds as I could on this forum, then came up with my design.

My design consists of a barrel built out of tapered fire bricks, and insulated primarily with Foamglas, and additional fire blanket.
I'm intending to finish it with a tiled roof.

I've had to teach myself bricklaying to do this project, and treated myself to a cement mixer to enable me to cast the hearth in one go.





The foundation slab is laid, and was reinforced with steel mesh. The support walls were built using a single layer of engineering brick, then a damp proof membrane and dense concrete block above that.

[davenott]

Support walls finished and concrete lintels in either end.
I am building a round front to the hearth slab, and you can see me bending the plywood former in this shot.

[davenott]

Getting ready to pour the hearth slab. It is reinforced with 12mm rebar which was wired together.
This is when problems occurred. I had bought a cement mixer so I could quickly mix enough cement to pour it in one go. I had all my concrete mixed and poured 5" thick, but the my wife's appendix burst and she got rushed to hospital, so I couldn't condense it as thoroughly as I would have wanted, and when the shuttering was removed you can see some voids round the edge.

[davenott]

I'm doing lots of mock ups to test my dimensions.











I'm using 14cm of Foamglas for my hearth insulation. Mine came in 7cm sheets, which are easily cut with a serrated knife or saw, and I staggered the panels.
I'm using Foamglas, because of its good compressive strength, good insulating property and because it's water resistant.

[davenott]

Laying the firebrick hearth.
I had intended to use fire clay on top of the Foamglas to give a level surface for the firebricks, but found this was unnecessary, and just laid straight onto the level surface of the Foamglas insulation.
(After I had poured the concrete hearth slab, I did finish it off when a layer of outdoor self levelling latex cement, to give a mirror flat surface to work with)

I laid the firebricks for the hearth end on, to give me a bigger thermal mass, as I'm intending to use it as a bread oven also, and I want as much thermal reserve as possible, at the cost of using more logs and time to heat up.

[davenott]

I made my arch support from 2 semicircles I cut from an old door then I linked them together to make the former. The former was sat on wooden blocks with plastic shims beneath, so it could easily be dropped to allow its removal. The arch sits on a soldier layer, to raise slightly, and allows me to achieve a 65% doorway height to arch height ratio.



The first arch stands.

[davenott]

Making more progress with the arches.

[davenott]

Final and 4th arch completed.



Back wall completed.



Tidying up the grouting inside.

[chas]

Novice or not, great progress and very neat build, love the front radius.

Chas

[davenott]

Building the front of the oven.
To support the flue and chimney, I used 2 lengths of stainless steel angle 5cm x 5cm and 5mm thick. I have tried to allow for expansion.

[davenott]

I have tried to shape the flue internally, so it doesn't constrict too suddenly, and it am hoping it helps it draw better.
I have tried to minimise all mortar joint thicknesses.
I will be extending the chimney itself, by another foot or two, and I will be further reinforcing the base attachment of the chimney.















In the photo below, you can see the cable running from the thermocouple in the hearth floor, I have another one in the firebrick roof of the dome and will be fitting a couple more within the insulation etc. I bought thermocouples with 3m leads, to they can all reach the temperature reader.

[davenott]

1st gentle fire lit today to begin the curing process. I intend to do a series of fires over the next week, gradually building up the intensity.
The flue and chimney seemed to be drawing well.
I'm thinking of building the front decorative oven arch, using Tudor 2" bricks. I was initially going to use blue grade 1 engineering brick, but now like the idea of using the reclaimed Tudor brick.
A house nearby is being re-roofed, and most if not all the original clay tiles have ended up in 2 skips, so I might see if I can negotiate enough for the oven roof. One of the skips seems to contain hundreds of apparently up damaged tiles, and I believe they are the original roof tiles, and may date from 1930's I'd guess.

[davenott]

I'm now onto my 3rd fire, and it was great seeing it burning last night.
I was too late to get the roof tiles I had hoped to get (they were buried under about a ton of rubble in the skip when I went to speak to the house owner yesterday,) but I spotted some old ones in the reclamation yard today, and have taken some samples, they vary from 50p each to 85p each depending on the batch for the handmade clay tiles and vary from approx 50-150+ years old.
I have bought the reclaimed bricks for my front arch. They are 500 year old Tudor blue ended bricks, and they let me hand choose the 25 I needed, and I got them for £62, with a few tiles too.

[5leafclover]

Loving the build so far and I'm planning on stealing a few of the design ideas, probably starting with the foamglas layer and probably followed by the brick starting layer!

Checking the foamgla spec sheet, it's recommended max temperature is 430C, which sounds a little borderline, but I reckon we can get away with it. The supply of calsil I had my eye on seems to have dried up, so foamglas seems like a cheaper alternative without the mess of vermicrete.

I was wondering what the size of your upper slab was, so I can get a feel versus my own plans?

[davenott]

My hearth slab is 120cm x 170cm. If I was doing it again I would increase each dimension by 10cm.
Foamglas softens at 730'C, so no chance of underside of hearth firebricks reaching that temperature. Before deciding on Foamglas, I read quite a few write ups of people successfully using this. I have used 14cm for the floor insulation and for the oven dome I am using 2.5cm of fire blanket (body soluble) and 7cm of Foamglass.

The foamglas is easy to cut, either with a saw or serrated knife. It gives off a horrid smell of rotten eggs when you cut it! It has a high compressive strength, so can deal with weight of oven no problem, but it is brittle and easily damaged if left exposed, so requires covering and not left exposed in oven design. It is very light.