Pompeii Build

[doms1]

Hi everyone,

I'm embarking upon a pompeii build, as a complete novice to pizza oven building. This forum has already been a wealth of information and has helped the design evolve plenty. I've already built a base from concrete blockwork, faced with some reclaimed bricks which I already had, and then filled with rubble which I needed to get rid of. Topped off with compressed scalpings and then brickwork finish. 

I'm now just beginning the pizza oven build itself. Calcium silicate board has gone down and now about to start the tricky job of cutting the firebricks.  

I'm keen for any advice - this seems like the first tricky bit to get a good circle! Am I recommended to lay the floor bricks in homebrew or simply place them down loose and then hold them in place with the solider course around them? 














I'll keep posting progress as I go - hopefully should make a reasonable start on it this week!

[oblertone]

Oven floor bricks should be laid loose in case you need to replace one, a scattering of sand underneath will help you get them level; the gaps will fill with ash after the first firing and no-one will notice. Between the floor bricks and the soldier course it is common to place a ring of cardboard to ensure an even gap and stop your mortar gripping the floor bricks. It is even more common to lay the soldiers first then cut the floor bricks to suit, but either way works.

[doms1]

Slow but steady progress this week. Soldier course is in and floor is cut. Getting everything perfectly circular and cut accurately proved more difficult than I had anticipated with the angle grinder, but we seem to be more or less there. Less accurate than I had hoped for, but I can’t afford to waste firebricks so the gaps will just have to be filled with ash. Onto building the dome next, but that is going to have to wait until it cools down a little!

[oblertone]

A cheap gazebo from eBay provided welcome shade and kept me dry while working on mine.

[doms1]

No update for a couple of weeks as I’ve had to do some ‘proper’ work, but the dome is starting to appear, slowly but surely. Might manage to get another course on tomorrow if I’m lucky. Discovering that fire bricks are flipping hard and are munching through the diamond discs on the cutter disappointingly quickly! Despite best efforts, there are some small gaps between the bricks in the dome. Is it worth pointing these with home brew?

[oblertone]

Home-brew is cheap and easy to use, therefore any extra should be slathered on the outside of your dome to hold the bricks and fill any gaps from the outside.

[gez]

I found cutting the bricks in half with a good lump hammer and brand new sharp bolster/ chisel the best method. Save the diamond blade for more tricky cuts

[doms1]

Jun 15, 2020 21:09:34 GMT gez said:

I found cutting the bricks in half with a good lump hammer and brand new sharp bolster/ chisel the best method. Save the diamond blade for more tricky cuts

Thanks Gez. Hadn’t even considered using a chisel. More progress - I’ve gone with a sand corner for the top. Now to try and work out how to feather the ‘porch’ into the main dome!

[doms1]

I've managed to make some more progress and the bulk of the dome is now done. I'm scratching my head about the join between the front arch and the rest of the dome, along with where the flue will sit. Is there any pearls of wisdom on this, or is it really a case of lots of careful cuts to try and get the angles right?

[oblertone]

I cheated and bridged the gap with a piece of angle iron then built on top of that; otherwise it’s lots of careful cutting.

[doms1]

Apart from a couple of cuts, I’ve pretty much finished the dome this weekend. It’s going to be a little rough and ready, but hopefully should work. Annoyingly I’m a handful of fire bricks short, but the last few bits at the front that need them will have to wait until I get some more in a couple of weeks time. I’m going to wait until it has rained later this week before starting on the Vermiculite insulation, but how thick does the vermiculite need to be to get decent heat retention? The thermal blanket is a bit pricey to use unfortunately!

[downunderdave]

Be careful if using a vermicrete mix against the inner dome with no blanket in between. As the vermicrete mix contains a very large proportion of water, if it is not eliminated then you risk firing the oven and turning it suddenly to steam, creating damage to the oven. Allowing the inner dome to dry for a min of one week (weather dependent) before proceeding is advisable, as is building the vermicrete over the dome in layers of no more than 1.5" thick and allowing at least a week for each layer to dry. If you use a 10:1:3 (by volume) vermiculite, cement, water mix, then you need a min of 3" thick vermicrete insulation.

[truckcab79]

Looks good. Somehow missed this build before now.

Couple of things which it’s probably too late for but I’ll add anyway. Not sure what you are using but Erbauer brand diamond discs are the best value and longest-lasting that I’ve tried. Screwfix sell them.

Not sure if the arch you’ve built is being covered or is the finished version but worth cleaning up excess mortar as you go along. Scrape off and then do final clean with a damp sponge. It wipes off really easy before it’s set. If you intend pointing up later then scrape out 10mm when it’s partially set, leave to set and then point it neatly.

Look forward to seeing this finished.

[doms1]

Thanks for all the advice to date. The second diamond disc I got was an Erbauer and has lasted well - I won't need another. The arch is going to be covered over on the top with insulation, and I am going to build a second ring in front of it, offset by 20mm so that I can slide a door in. I'll be taking much more care to keep the mortar neat on that one as you'll be able to see the pointing, whereas you won't anywhere else.

I've had a browse of the Vitcas website and found discovered they do ceramic fibre by the metre (not sure how I missed that before) so as I'm passing by them next weekend I'll pick up a few metres of it to wrap the oven in before adding the vermiculite outside. Couple of weeks pause on work now while I wait for materials!

[doms1]

So a fair bit of progress since the last post. I’ve finished the dome, wrapped it in ceramic fibre blanket, covered in vermiculite (very crumbly, but got there adding a little at a time) and started lighting some curing fires. The brickwork inside wasn’t as neat as I had hoped as the home brew had ‘leaked’ into the sand former as I was bedding in each brick, but it stayed upright when I took the sand out from underneath which was the main objective. 

I’m now finishing off the front arch with the neat brickwork and adding the flue. On the curing fires, I’ve had quite a lot of smoke coming out of the front of the oven. I’be read that adding the flue should help reduce this? It also seemed to die down as the fire became a little more established. I’m a little stumped about how I’m going to fit the flue to the top of the oven. Is there a generally accepted way of achieving this?