Lower ground floor court yard

[HenrikK]

A lovely sunny day here in Brussels. I started digging. At - 60 cm gravel mixed with what remains of older buildings (our house is from 1886). First 20 cm sand, then soil for another 20 and then the gravel mix. Its humid but not wet. I definitely need to waterproof the edges before building an oven in it.

[Gulf]

The hemisphere shape is the easiest to build. Also, with a deep entry, the barrel vault design wold make for an even farther reach imo.
Think, and rethink any and all ways of keeping ground moisture from getting to the oven and it's insulation. I did a french drain around my oven stand which is built into a retaining wall. I'm glad that my oven is not also under grade.

[HenrikK]

Yes, Gulf, that's a good point, any humidity would drain down the edge of the soil and not reach the WFO which would lower the pressure on any water-proofing

On shape: The wall is 40 cm thick so the entrance before the chamber would be 40 cm or 16''. What shape should I choose for the chamber given that?

[Gulf]

I also thought of putting a few inches of gravel under bottom slap for drainage

You may also want to include gravel on the sides.

[HenrikK]

Thanks for great answers!

The image is maybe a bit misleading. The wall is 170 cm high so with a dome height of 50 cm for example would give an oven floor at almost normal kitchen top level.

Waterproofing the bottom slab is a great idea. I also thought of putting a few inches of gravel under bottom slap for drainage (I used this very successfully to insulate the lower ground floor, dug out, 10 cm gravel, on top a floating construction of extruded styrofoam, fiber plaster boards (like Knauf Brio) and then tiles on top)

I will of course also have to see when I dig out if it is dry. It's generally sand under the top soil and quite dry, but you never know.

It's also a question of size, People here seem to build quite large, but I've seen that you are happy with your 21' David.

Cheers

[deejayoh]

You can can use xypex in your hearth to waterproof the concrete if you want to do something on grade/sub grade. you need to basically build a water proof box - and as david points out you will still have an uncomfortable to work with oven.

http://www.xypex.com/

[david s]

You may have a problem if your oven is below the level of your garden. Ovens will pick up moisture easily because of the nature of porous refractory materials. Most oven owners find that moisture is their enemy and find it reduces the ovens efficiency. Your plan would also mean a very low working height. I think you may find a better plan would be to buy a small oven kit and mount it on top of that low wall with some extra support behind it.

[UtahBeehiver]

Look at david s ovens, he has done a numberbof small diameter cast dome ovens. Small foot print but enough size to do pizzas and roasting.

[HenrikK]

Hi everyone,

I want to build a pizza/bread oven in our garden.

The problem: We don't have a big garden (we live in a town house in central Brussels) so I don't have anywhere to put it.

The solution (or the only solution my wife has agreed to yet): At the back of the house, the ground is level with the ground floor, but there is a small courtyard to the lower ground floor or 'sous-sol' as it's called here, see photo. Towards the garden, the small courtyard ends with a wall 150 cm high and 30 cm wide. Behind it I have my bbq area, Weber, small kamado, dustbin tandoor, etc.

My plan: Break through the wall for the opening of the pizza oven and dig a hole behind it, build the oven in the whole and fill it up, put back tiles and then I would have a oven that hasn't taken a single square cm of space in my garden.

My questions: Has anyone done this? What advice do you have for me?

What shape? Dome or barrel?

Thermal mass? Brick thickness?

Insulation?

Supportive concrete layer? Above and not below, or both?

I'd be ever so grateful for any help on this!

Henrik