Attempting to build an oven with no clue!

[jamesfromlara]

[jamesfromlara]

Hi All, currently out of employment so thought I’d try to knock up a pizza oven, excuse the shabby brickwork btw, total novice! Anyway I hope I’m on the right track, I should’ve looked on here before I started...
so ive got a 1200 square footing slab and was going to suspend the hearth slab on the brick pillars alone but I keep imagining it collapsing and I have a young child so It’s a bit of an afterthought but I’ve started forming up the internal sides so the hearth and footing slab are joined. I drilled some holes and tapped some 12mm rod in and attached some heavy mesh to it which will also be attached to the mesh in the hearth slab. Am I going about this the right way?

Ideally I’d like some advice/ideas on the next stages after the hearth slab. I’ve basically got a zero budget, but have lots of red clay bricks, and all the brick sand, cement and lime I’ll need.
Was thinking I’ll do two courses of red bricks for the hearth for a bit more insulation. Although I have enough fire bricks the do the hearth within the dome but they are only 50mm thick. So maybe a course of reds and Then the fb’s?

what ratio of lime cement and brick sand should I use for the arch and the dome, I’ve tried to look through this site but haven’t got a clear answer yet, hope these basic products will be good enough, I do have half a bag of cement fondue someone gave me years ago too but no idea what to do with it.
Im very excited about this project now, hoping that I can make it work. The dome looks scary but I’m going to try and form it with packing sand to help guide my poor bricklaying. No idea how to tackle the arch door yet lol, cheers, james

[UtahBeehiver]

Our Web page host offers a e-plan for $3 usd.it covers all the basic construction issues for a wfo. It would be a wise investment before you get too much farther along. FYI, doube layers of floor brick does NOT GIVE you more floor insulation but more thermal mass which means the floor will stay charged with heat longer but means more wood and longer times to heat saturated but does not offer a lot of insulation value.

PS 3 sand 1 lime 1 portland cement 1 fire clay is a good basic home brew mortar with enough refractory characteristics for an wfo oven.

[wotavidone]

By all means reinforce your stand if it makes you feel better.
Are you in Lara, Victoria, Australia? If so, you are likely to be able to obtain bagged builders clay from Boral or Cement Australia. (For reasons I cannot fathom, they are not available in South Australia).
Anyway, this means you can make the classic Homebrew mortar. 3:1:1:1 sand:cement:lime:clay.

50mm firebricks will suffice for the floor. One proviso - they must be the dense fire bricks, not insulating fire bricks. You can tell by the weight. A dense 50mm brick will weigh nearly as much as a 3 inch red brick.


There are two extremes of WFO building.
I call them low tech and high tech.
High tech = fire brick, cal sil board underfloor insulation, proprietary high temperature mortar, ceramic fibre blanket insulation over the dome, etc., etc.

Probably not the right course for a man with an abundance of red clay bricks and zero budget.

I expect you will be going low tech.
Red clay bricks, home brew mortar, homebrew insulation.

You've got to get a slab poured on that stand. Then you need to get a layer of insulation down.
Even if you are not intending to insulate the dome, insulate under the floor.
You can change your mind about over dome insulation. Not so with the floor, so insulate whether you think you need it or not.

Under the oven, the insulation must have a degree of rigidity.
If you can get vermiculite or perlite cheap, guys swear by "vermicrete" or "perlcrete"

I've seen two ovens built with Hebel as underfloor insulation. Neither has collapsed, but the jury is out on the longevity.

Once you have the insulating layer, mark out the oven and do the hearth bricks.
Two ways to go - floor inside dome, or dome on top of floor.
If your fire bricks are limited then floor inside dome. That is my preference when building ovens, anyway.

With floor sorted, build an arch.
Dome runs off that.
Piece of Pi.