Perforated engineering bricks for the dome

[ChurleyBird]

Hi all!

I'm slowly working through my own oven with a lot of help from this forum, but I have a question. I've bought some fire bricks for the base of my oven but at £~3.50 per brick I just can't afford them for the whole thing. So, I'd like to build the dome this out of engineering bricks bank holiday weekend but my local B&Q only sells perforated bricks. Will this be fine?

My thoughts were that a solid brick, if it did split in the heat, would still be held in place by the other bricks and mortar around it, but a perforated brick might crumble. But maybe I'm worrying too much.

These are the ones I was going to buy:
https://www.diy.com/departments/wien...3404876_BQ.prd

Thank you!

[UtahBeehiver]

Perforated bricks will NOT work as your dome brick. If your budget is limited, there are a couple more economical options, one is a refractory cast oven with a brick floor. Some UK builders have been able to use old heater storage bricks for the floor. Also some UK builders have been built their domes out of old solid red clay bricks with some success. A sand mould with refractory cast has been used quite a bit lately on the forum. DavidS is our resident expert, look at his posting and threads.

[ChurleyBird]

Oh no, that's not the answer I was hoping for! What's the problem with them, do you think they risk splitting?
Thanks for your help.

[fox]

A well designed oven will heat the dome to around 500c ... only specialists materials will withstand those sort of temperatures.
The sort of bricks you linked will not last any time at all, they will crack crumble and quiet likely explode if there is trapped air inside.
Casting an oven will be cheaper than fire bricks , depending on the oven size, refactory cement will be around £150. Home brew casting will be cheaper still.

[ChurleyBird]

I'd already bought the bricks so I thought I'd test a few for my curiosity: I put a few into a campfire and stoked it as hot as I could. I can't attach a photo right now but I will when I get home - they completely disintegrated. Thanks for saving me from a sad mistake!

I think I'll go the casting route, and use the spare sand to make a little patio afterwards!