Trav's pizza oven thread

[Trav]

There seems to be a bit of interest in pizza ovens on these boards, so I thought I'd start up a thread cataloguing my efforts to construct a pizza oven. Let me know if it is interesting and I'll keep it going.

History:

I've been thinking of a pizza oven for a little while, and bugging SWMBO for permission to commence construction. We recently got some paving done and thought that we should include a pizza oven in the basic design.

I've attached a google sketch up plan of the backyard that I did before we started the landscaping. The design was really helpful in talking with landscapers etc. For those who aren't using sketch-up, a couple of image files are attached. Apologies for the dodgy rendering of the oven.

The big brown retaining wall was always there, so it is only the other paving that is new.

I was fortunate in a sense that there was an old gas BBQ built into the retaining wall in a pretty handly location. It didn't take all that much convincing to get the necessary approvals from SWMBO to rip the old gas BBQ out and to excavate out a bit more to provide space for the oven.

Stay tuned for episode 2...

Trav

[Trav]

Episode 2:

Paving was finished a few weeks ago - we're really happy with the way it has worked out. First photo shows the completed paving, but plenty of landscaping still needed. You can see the gap where the old BBQ was.

I was meant to get into the pergola (I'm doing that myself of course), but I can't seem to get the timber at the moment. Instead, I thought I'd get a head start on the excavation for the oven, with the intention that I might be able to prepare the slab next weekend (or maybe the weekend after!).

The plan:

My basic plan is to dig out the area around the old BBQ space, making enough room for a slab 1500 square. I will also build up the bench seat directly in front of the BBQ to bring it level with the finished height of the slab. I decided to do this as I could then bring the oven forward a bit and it would mean that the bench wont get in the way if I'm trying to get food in and out of the oven. I thought it might look pretty good too.

I'm intending to make the slab about 100mm thick, without reo, but would appreciate advice on whether that would be suitable. I'm a bit of a noob when it comes to concreting, so advice would be graciously recieved. I don't have a mixer, so thought I would do it in the barrow - not sure if this is realistic. Let me know what you think.

As the slab will be some 350 below the surrounding ground, I was intending to build a retaining wall around the edge of the slab with left over wall blocks used to make the bench seat. That would leave me with a 1200 square slab for the oven.

Trav

[Trav]

Episode 3:

The oven itself - this has been the most interesting part. I originally was looking for a kit, but they all seem to be made in WA, and seem to cost a fortune. COnsidering it is pretty cheap to get most of these materials, I've decided to give it a go myself. Could be a disaster.

There's a fair bit of into on the web about pizza ovens. Ive decided to go with a half-barrell design (ie not a proper dome with a round base). It would have flat front and back walls, but an arched profile. The sketchup diagrams give you the basic idea. I'm working on some plans, but haven't finished yet (well, haven't quite started yet, but I have some ideas)...

My basic plan is to cover the slab with left over brick-sized pavers - they would form the base of the oven. I don't propose to cement them down or anything, just pave them tightly and butt them firmly against the retaining wall to prevent any movement. Interested in views on whether I will need anymore insulation than just the slab and single paver.

Construction sounds pretty easy, but I suspect it won't be. My plan is to build the front and back walls with light coloured, solid clay bricks, using a think spear of refractory cement to bind them. Then, using wet sand, build a mould of the dome and brick it over, filling the gaps between bricks with refractory cement. Once it has gone off, remove the sand through the opening at the front and - hopefully - the dome stays up. Then it is on with more layers of refractory cement, some insulation (foil edged fibreglass sheeting), then render with a normal cement mix. Sounds easy.

As I said, design is still being worked on, but I hope to post it in the next few weeks. I am intending to integrate a chimney of some form to stop the smoke coming out towards the paved area.

As I said, would appreciate any feedback or ideas as I progress.

Trav

[brickman]

Not a bad idea when rendering over the outside of the oven to loosely stretch chicken wire over the insulation and pin in place with a couple of nails , then when u render push it into the chicken wire and build it up , this not only helps the render hang but will go a long way to prevent cracking . Keep the render moist ( lighly spray with hose regularly for first 24 hours) . Most people advise conditioning the oven when u use refractory cement ie. small fire for 1st hour , medium fire for 2nd hour etc. as most refractory cement even air set needs the heat to harden , and can become crumbly if fired too hot initially.I normally would use 2 layers of pavers on floor , easier to replace these than the concrete , and would use refractory cement inbetween the ones on the 1st layer and dry lay the top layer. regards

[yaryetnom]

Hi Trav,

I have just built an oven. Photos in the cooking threads. With your slab & bricks forming the base make them thick. My slab was 150mm & a layer of bricks on their sides. The other important design issue is the ratio of the height of the door to the dome. There are some links to good sites also on the cooking thread "sourdough".

Look forward to following the progress. Good luck.

Ray

[yaryetnom]

:BThat door to dome height is about 64% to allow for sufficient air flow to assist the fire to burn & retain maximum heat.

[Trav]

Thanks all.

Chicken wire sounds like a good idea. Cheap and effective - just the way I like it.

Will also make the floor thicker - perhaps a 100mm slab, plus two layers of bricks/pavers.

Will keep you up to date with progress.

Trav

[Trav]

Hoping to pour the slab this weekend. Just wondering what kind of mix would be best for the slab?

It will be about 1500 square, and around 100-150mm deep. I'll cover it with 2 layers of clay bricks as the base of the oven.

Any advice would be appreciated.

Trav