clay bricks in a wood fired pizza oven

[Trav]

Hi

Does anyone know of any reason I couldn't use clay bricks or pavers to make a wood fired pizza oven? I would expect that these bricks would have been fired at a very hot temperature, so they would be able to withstand the heat.

Austral (as far as I can tell from their website anyway) have some bevelled bricks (for use in arches I would imagine) that look like they might be the business. I would fill any gaps with refractory cement or firing clay, and then insulate and render.

I'm thinking of using old shelves from a proper pottery kiln for the bottom, sitting on top of a thick concrete slab.

Thanks

Trav

[journeyman Mick]

No problems, you could use normal bricks for an oven or kiln for up to about 1000 deg C.

Mick

[ratchet]

you maybe interested in this web site


http://www.woodfiredovenworkshops.com/

Rod

[Honorary Bloke]

Perhaps this should be in the Cooking Forum. :D

[Trav]

you maybe interested in this web site


http://www.woodfiredovenworkshops.com/

Rod

Thanks Rod

I've already been in touch with Alan Watt who runs these workshops. There aren't any in Canberra until next year, so I'm keen to give it a shot myself. If it doesn;t work, I'll try his course!

Trav

[ratchet]

Perhaps this should be in the Cooking Forum. :D


when the oven is built , it then may go to the cooking forum

when you make a kitchen table , it's woodwork , when you use it it's cooking or eating

[Honorary Bloke]

when the oven is built , it then may go to the cooking forum

when you make a kitchen table , it's woodwork , when you use it it's cooking or eating

Thanks for clearing that up, mate. :wink: :D :D :D

[mikm]

gday trav,
i built my oven using standard clay house bricks (solids, not wire cuts) a couple of years ago and its been fine so far. i wasnt keen on spending too much money on a project that may not have worked (since i plucked my design from behind my left ear :) ), so i chose not to use furnace bricks at about 3 or 4 au$ back then. i figured since house bricks were baked in an oven during manufacture anyway, they must be able to withstand a reasonable amount of heat. as i wasnt planning on firing pottery in it or using it as a commercial pizza oven every day, any small amount of degradation in the bricks over time didnt worry me. i did, however, source (look up refractory supplies in your local yellow pages) heat rated mortar - cement based mortar would be far more likely to break down and result in sandy/crunchy pizzas. its less likely that the whole oven would fall in since its a self supporting arch, but grinding sand between your teeth thats fallen out of standard mortar isnt very appealing.
as already mentioned, the oven i made a while back (theres a thread on it around here somewhere) is still going strong with reasonably regular use, so i say 'go for it!'

[Damon_11]

I've been reading this topic for a year or so. I did read that to save some money the Whiter Solid house bricks as opposed to red ones will do the job up to 1000deg. Suggest that you use firebricks on the base and white bricks on the dome. If you then cover with the dome with the refactory cement and vermiculite mix (from your hydroponic plant shop) That should do the trick....

My project starting in the spring after the new patio goes up :U

Just got to find a supply of new refactory bricks in Perth. There's heaps of mining and industrial in the state, so there should be a stockpile somewhere we can raid for cash.

I had better dig through my saved documents - I have heaps of plans and instructions which I can post.

Cheers

Damon

[mikm]

Hi Damon,
I managed to find vermiculite, refractory cement and refractory bricks at the same refractory supplies place in Melbourne. 100 mm+ of vermiculite/r. cement in a firm slurry seems to have worked well on my oven. Before I poured my driveway over the top, you couldn't feel heat on top of the insulated dome after a couple of hours of firing.

When I was sourcing my materials, I seem to recall that a 'pizza oven tile', dimensions of 300x300x40 (approx, cant remember specific thickness) was something like $30 each. With reference to my earlier comment about not wanting to invest any real cash in an (at the time) un-proven, home brew design, I decided to use clay pavers for the floor instead, which seem to work fine. A slightly more economic option at about $1 each.

Interesting suggestion on the brick colour. Anybody know why this may be the case? I used some 'coach house greys' I had lying around. Perhaps these are somewhere in between whites and reds in terms of heat resistance.

Im guessing here, but I reckon I must have used the oven at least 30 or 40 times over the last couple of years, and the only real sign of wear is cracking in one the base tiles. Mind you, I always start the fire in the same place in the floor and at night after pushing the fire to the back of the oven, the floor glows red for a while. I bought spares with the intention of replacing cracked ones, but the oven still works fine, so I cant be bothered. The bricks and mortar of the dome still look 'brand new', though.

[mnorman007]

Where in Perth are you getting your refractory mortar from Damon? I heard someone say Bunnies once but headed there tonight with no luck.

Also, whats the plan for the dome/cover as far as insulation goes. I've heard the insulation blanket is popular but never heard of where to get one from. Or, are you just going single width bricks with a vermiculite render look on top?

Love to gleem some wisdom from you guys. Like you say, its a bits hard once its finished to wish you'd done it differently.

M.

[Damon_11]

Where in Perth are you getting your refractory mortar from Damon? I heard someone say Bunnies once but headed there tonight with no luck.


Forget bunnies, check http://www.hotfrog.com.au/Products/Fire-Bricks for Refactory suppliers. Suggest going for larger volume suppliers as they might be receptive to odd lot cash deals for bricks and insulating materials. My BIL is a mech engineer and knows where to find such things down the Kwinana heavy industrial region.

Here's some of my better links that I can remember

http://traditionaloven.com/tutorials/wood_fired_oven.html
There's a recipe here for home made refactory cement.

http://www.avalonrecords.com/brickoven/
http://www.abc.net.au/gardening/stories/s943952.htm

And the white bricks contain Alumina Silicate the stuff of fire bricks. The more alumina or magnesium, the better the insulation, but more $

I promise to get my broke PC working and dig up my fact sheets / plans and post them.

Cheers and happy reading...DC

[Trav]

Thanks everyone, seems like lots of people are interested in pizza ovens.

I'm thinking of starting a whole new thread that will be my step by step recod of how I build this oven.

I'm still considering a few options

1. a kit oven. There are heaps of places online that seem to make kits. They are pretty expensive, especially as I am getting some landscaping done and will have quite a few pavers left over I imagine. They will be a sandstone colour, so would be pretty light.

2. a brick dome that I design myself. The key issue here how to make a tight dome with square bricks. I've found a supplier of solid, square clay fired bricks and have located a supplier of refractory cement. I'm concerned that the square bricks will not form a tight dome like angled bricks.

I've even looked into making clay bricks, sun drying them, and then firing them in the oven once I have built it. Sounds like a lot of work.

3. Building a solid dome out of firing clay or refractory cement, using sand to create a mould.

I'm interested in the actual construction methods others have used, particularly if you found angled bricks or if you managed to get a good result with square bricks.

Trav

[mikm]

gday trav,
some thoughts on your suggested options:

1) kit oven. wot, buy one? come on fella, dont take the soft option! :U only kidding, mate. seriously though, most of the pre-fab units ive seen have been too small, i reckon. as well as being hideously expensive for what they are.

2) your own brick dome. now you're talking. i assume you've already searched the forum on pizza ovens and seen this already, but one of the photos in my first post of this old thread http://www.woodworkforums.ubeaut.com.au/showthread.php?t=19702 shows the process i used to make the dome. i used full size ordinary house bricks for the arch section and broken bits for the hemisphere at the back. this photo below shows the dome at an earlier stage to clarify this, as i'd already 'rendered' the finished dome to get rid of leftover mortar in the original pic. note: the vermiculite insulation was still to be applied. i also included a pic of the bucket of pre-mixed mortar i used, for what its worth. from memory, it was about $40 / 20kg a few years ago, but it trowels nicely and has so far stood up to temperature in my oven.
unless you have a burning desire to do it anyway, i suspect there are probably far too many headaches in making your own bricks and potentially in longevity of the oven.

3) cast in place. definitely do-able, but im guessing potentially a bit more mucking about to get it right and probably somewhat more expensive.

by the way, the furnace bricks i mentioned in an earlier post were available in either standard rectangular or keystones of varying angles to make different size arches, if you wanted to go down that route. Given how well my half-ar5ed effort with normal bricks works, im not convinced its necessary though.:D

what ever you decide, keep us posted. if you end up buying one, give us a product review.

cheers,
mick

[Damon_11]

Thanks Mick, that has answered one of my questions about how to form up the arch over the top and cement it in place - Use heavy sand or even a dry mix of tilers float cement and then dig it out afterwards. I had also thought of using wood MDF template.

In one of my links, they had a recipe for homemade refactory cement http://www.traditionaloven.com/tutorials/concrete.html so you could form up a slurry over the sand dome quite cheaply. Looks like an experiment coming up......DC

[mikm]

the home brew refractory cement and cast-in-place-dome themes of the last posts by damon and trav got me thinking...

if the mix suggested in damon's link works, it should be pretty straightforward to pour over a sand dome. i reckon id use some sort of reo as well - in a shell probably 100mm or so thick, but i wonder if there would be any problem with different rates of expansion between the cement and steel causing cracking/failure of the structure?

if you're going to cast cement or lay bricks over a sand core, use some sort of interface breaker. when i dug out the sand core after laying the bricks of my dome, some of the sand was stuck to the mortared joins. i reckon this would be much worse if the whole dome was cast over the sand. this then proceeded to rain down from the roof of the oven for some time. crunching sand in your teeth in the middle of a mouth full of pizza is a bit like finger nails on a blackboard. nasty

i dunno - maybe laying builders plastic or something over the sand before hand will stop sandy pizzas

[mikm]

apologies for starting to monopolising this discussion, people :-. since its his thread, hopefully at least trav and some of the rest of you are finding this useful...

anyway, some further thought on the home-brew mortar i mentioned:
the arch section of my dome was mortared in place with some home-brew refractory mortar and i did the hemisphere at the back with a tub of the pre-mix i mentioned earlier. while the home brew seems to be holding up (pun intended) fine, im not sure id recommend the mixture i was advised to use at the time.

it was suggested to me that the inclusion of lime (afaik, in brickies mortar to clag it up a bit for workability and to slow down the curing reaction of the cement) and clay (the red component of brickies sand) would be no good at high temperatures. i dont really recall the reasons why. the suggestion was that i should only use refractory cement and washed sand to make a properly temp stable mix.

im guessing now, but i suppose i might have used something like a 5 or 6 :1 (s:c) mix. anyway, an initial test with a small batch confirmed that it would actually bind to bricks when cured, but with no lime or clay present, it was terrible to trowel up.

cant really see what the problem with lime would be...

[brickman]

Have done a few pizza ovens and my preferred bricks are solid white or cream clay pavers 230 * 110 * 40 mm as these are easier to roll the dome over as they are only 40 thick and being solid have better insulation properties . I also like to use a triple layer in the base with the top layer dry laid (no refractory cement ) as they can be easily replaced if necessary. When u place sand to form the dome throw in a few 8 " concrete blocks to help fill the void ( you will appreciate this when u have dug out the 3rd wheelbarrow full of sand ). Some like to spread cling wrap over the sand to prevent sand getting in the mortar joint . The only measurements I have found of importance is the opening height of the door to be 3/5 ths the internal height of the dome e.g. door height 300mm / internal height 500mm. Any other questions please ask ,not guaranteeing i have all the answers though. , regards

[RedRaven]

First post - hi ewverybody!



I'm thinking of using old shelves from a proper pottery kiln for the bottom, sitting on top of a thick concrete slab.


Hi Trav - don't do this (use an old shelf) - pottery glazes use some pretty nasty heavy metals etc in their makeup that are fine in pottery, but I wouldn't be cooking anything on them, just incase it gets into the pizza.

Still, reading about it is making me hungry. :)

[notenoughtoys]

I'm interetsed in building a pizza oven and had been thinking of using secondhand bricks from an old fireplace/chimney, would these be suitable to use for making a pizza oven

Tx

Bob K

[brickman]

Realistically most bricks have been fired at near 1000 degrees , the most your electric oven will go to is around 280 degrees . The most your domestic pizza oven will be is between 180 and 250 degrees ( have a wireless weber thermometer in mine ) so the bricks will not be the first point of failure . The biggest mistake is to use a cement rich mortar free of limil as this is too brittle to take the variation in temperature , regards

[yaryetnom]

Just spotted this post. I have posted a couple of photos of my nearly finished oven under the cooking section. Insulation & waterproofing to go on yet. Floor & dome made of solid house bricks & has handled the heat so far after 6 firings. The bricks in the external brick work are left overs from the house & very much seconds and this is second time I've tried brick laying, maybe I'll use a level next time.:B

Wish I'd built it years ago.

Regards,
Ray