Lifespan homebrew cast oven?

[Kris S]

As the title suggests, what is a reasonable expected lifespan of a one piece cast pizza oven using the homebrew method.

Assuming the oven is completely protected from wind and water, normal firing cycles, gentle use as in not bumping into the inner dome with peels, tools or wood logs.

Just wondering what to expect for myself. I can't see any reason why the homebrew would degrade with the heating / cooling cycles once it has survived it's first year?

[david s]

Because the homebrew is widely used as a mortar for brick builds and proves highly successful, in fact in many ways better than expensive and difficult to manage refractory mortar, I could see no reason why it couldn’t be used as a cheap castable. So around 12 years ago I suggested to two customers that they try it, but with no guarantees. I’ve lost touch with one, but see the other usually once a year and he reports the oven is still performing fine. I have no idea how frequently he uses it, I expect not that much, but it’s still a pretty good test. The homebrew is very cementious rich. Both the lime and the Portland are cementious while the clay is not, it should be considered a very fine aggregate. That leaves the ratio of cement to aggregate of 2:1 which is very rich. As the homebrew operates at the upper end of its limit, and Portland begins to fail at around 300C, the lime then takes over, it starts to fail at over 500C. Should that fail then the clay takes over, undergoing its alpha change at 573C where it become permanent ( won’t return to mud if wet). It is important to resist the temptation to fire the oven really hard in order to achieve this as there are a number of chemical changes as well as incompatibility of thermal expansion of different materials at these higher temperatures. This results in micro cracking which is likely to get worse if frequently repeated. I think the real answer to your question is, who knows, but try it and see, a rebuild after ten years is not bad when the materials are so cheap and having done it once you’ll do a better job the second time around.

[Kris S]

a rebuild after ten years is not bad when the materials are so cheap and having done it once you’ll do a better job the second time around.

True, casting the dome was easy, making a removable mold for the entry was more challenging the first time, I should do better next time.

At least the same amount of time and work went into building the enclosure, which is not built to be neatly deconstructable but would rather have to be wacked down if/when I ever need to do another cast.

If I need to redo it in like 10 -15 yrs time, I can try the Igloo style perhaps.

[CoastalPizza]

My homebrew cast oven was completed just under four years ago. After 80+ uses (plus several hurricanes) It is still in great shape and going strong.

[Kris S]

Thanks for the feedback, and you've got quite a unique oven design, I like it.
Why did you decide to install a chimney after a while? Was the draft not enough without one?

[CoastalPizza]

I’d always planned for a chimney, it just took me a while to finish. Initially, I just placed a piece of chimney pipe loosely in place since I was in a hurry to get started making pizza.