Post by hiddenspringvineyard on May 20, 2018 10:09:54 GMT
I've finally taken the plunge and started the foundations for a 100cm diameter pizza oven. I've based the plans on FB and watching tons of videos and the many builds on this site which is amazing to see. I found working out the size really hard and ended up with the following plans. Now to dig out the foundations.
Very neat looking plans and I look forward to seeing how they translate into a WFO. My only comment would be that a 20cm flue landing seems a little restrictive as you've got plenty of room to extend forward. I'd bring the arch to the edge of the platform which would give you more space to construct a flue funnel.
Post by hiddenspringvineyard on May 7, 2019 9:35:35 GMT
Well it has taken over a year and I'm well overdue an update - apologies. We dug out the foundation hole back in April 2018. We are on hard clay so the bottom of the hole was pretty solid and we decided to add a layer of pea gravel - which happened in June 2018 with some assistance from Pinot and Bacchus our vineyard cats!!
By the end of June we had laid the pea gravel and cut a piece of rebar mesh to the right size and positioned it in place, however it wasn't until October - after harvest and wine in tank - that we were able to hire a cement mixer and put the foundation slab.
This last week we started laying the clockwork which will be 3 courses - we decided to build an opening into the design for storing wood but its pretty narrow. We managed to source come 50mm angle iron for the job which I'm hoping will happen in the next week or so.
Post by hiddenspringvineyard on May 7, 2019 9:38:52 GMT
I'm planning to pour the oven slab as 9cm of concrete - instead of gravel+sand+cement I'm planning to use ballast instead in the hope that this gives a better mix.
Unfortunately fibre board seems way too expensive to consider so I'm planning to add another layer of 10cm of vermiculite concrete - but first filling the edges with normal concrete to avoid chipping at the edges later on.
Post by hiddenspringvineyard on May 4, 2020 18:22:57 GMT
Finally making progress again, the bottling season at the vineyard got in the way but we have managed to build the form for the oven hearth slab.
I used a black plastic sheet covered in oil so hopefully the concrete won't stick to the board.
Next I built a form for the perlite concrete under the dome and we poured more concrete around the outside of it.
Then filled it with Perlite concrete - which was weird and a bit like rice crispies!!
So now on to lay the oven floor at long last. The only issue is there is a shortage of 76/64 tapered bricks that I'm going to use for the dome so I have to wait a few weeks until they are delivered. In the meantime I'll dry lay the floor and cut the bricks - I plan to lay the soldier course on the slab and not on top of the floor - I think I need to leave a couple of mm gap between the soldiers and the floor - which I'll set in place with some fine sand and fireclay - a bit like tiling cement consistency. Will post photos when I can. For now I'm having fun with sketchup.
Placing the oven on the concrete slab rather than on the insulation will result in heat loss from your dome into the concrete slab which will act as a heat sink. The oven should be completely encapsulated in insulation. You could reduce the size of the oven so the base sits on the insulation.As you have poured a perlcrete insulating slab you will have discovered it takes a lot of water, more than double that which is required for the hydration process. That under floor insulation is really hard to dry if you build over it. I suggest you give it time to dry (see my attached test). Also it is prudent to have some drain holes through the concrete slab which will assist in drying this insulation as well as providing an exit for future drying should water find its way in there, particularly as you've designed a basin for its collection. These holes are usually cast at time of placement of the concrete, but you can drill up from the bottom until you get to the perlcrete.
Post by hiddenspringvineyard on May 5, 2020 16:28:47 GMT
Thanks, it hadn't dawned on me that I had essentially built a concrete basin!! Will drill some holes from underneath once I remove the forms - another 10 days to go (making 28 since pouring).
Also, I maybe wasn't clear - the soldier course will be built on the vermicrete insulation (which I meant as part of the slab!). In fact there is enough vermicrete in the oven slab to insulate out to under the fire blanket too once the dome is built. Its 100cm diameter dome and the vermicrete is 130cm diameter. Attached is the sketchup showing the soldier course - though I'm now thinking rather than half bricks to go for full height bricks but to taper them in towards the IT pivot point (around 7 degrees).
Post by hiddenspringvineyard on May 18, 2020 14:10:31 GMT
This really feels like progress. Today I removed the supports from under the reinforced concrete slab and it didn't collapse!! It still amazes me how strong concrete is!
I've also been busy cutting bricks for the oven floor. First I laid them out to see where they would go and select the best bricks for the floor
I used a rage evolution chop saw with a 255mm diamond blade (the evolution branded ones are for sale £18 each on amazon). I connected a Henry hoover to the rage to suck up as much dust as possible, soaked the bricks for 2mins in a bucket of water (until the fizzing stopped and there were no more bubbles, then set about cutting. Mostly it went ok when the cuts were around the circumference of the floor but where the brick had to have an internal angle it was a nightmare with the chop saw. Got there in the end though.
My big challenge now is to transfer the floor and landing onto the base keeping the orientation correct so that the landing lines up with the front of the slab. Any ideas how to do this? I had planned to start with the centre brick but if that ones out by a few degrees I could be in trouble. I dont like the idea of starting with the landing cos then I might not have the dome centred. Probably I'll go for centre brick and hope!!
1) stainless steel screws into rawl plugs - but I'm worried the rawl plugs will melt with the heat - will it? 2) concrete anchor fixing - but cant find any under 6mm dia so would have to expand the hole in the anchor plate - will this risk corrosion? 3) A2 through bolts - again smallest I can find is 6mm. I like that they are bolts for easy removal though suspect will concrete up to the chimney mount
Obviously will be using fire resistant sealant too, this is a question about the mechanical fixing...
Really appreciate any insight you have. Thanks David