Purple fire bricks v yellow fire bricks

[robinhood]

Hello I have managed to obtain what I think are fire bricks, they are a deep purple colour, are these different to yellow fire bricks and are they safe to use in a pizza oven, I read somewhere somethings purple fire bricks may obtain asbestos?

[oblertone]

Are they roughly square and about 5cm thick; might have ridges on one side and flat on the other ?

[robinhood]

Mar 4, 2021 23:28:17 GMT oblertone said:

Are they roughly square and about 5cm thick; might have ridges on one side and flat on the other ?

Yes that’s exactly what they look like

[oblertone]

They are storage heater blocks and commonly used for the floors of wood fired ovens (see link below for my build); some folk have used them to build entire ovens. If you are concerned about their content then use them whole but unfortunately no one can really say what they contain without analysis. FWIW you can still buy new ones which are more likely to be asbestos free; have a look on eBay.

[robinhood]

Thanks for the advice, they look identical to the ones you have used.

Love the pizza trolley concept, have you managed to finish it yet? I'd love to see the finished product.

May I ask for one final bit of advice? I was going to lay the bricks on a bed of fireclay and sand mix, but reading through some of these posts it looks like I may need to invest in some additional insulation like a ceramic board?

[oblertone]

It all depends on what’s underneath; in my case it was a steel tray and then air so I needed a barrier to stop the heat leeching out. If you are building more conventionally on a solid base then something like lightweight concrete blocks laid flat will provide sufficient insulation.

The finished oven should be visible at the end of my link, although its mosaic finish has recently suffered frost damage; but that’ll be subject to a different thread.