Recycled refractory/kiln brick

[Sparkman]

Hi everyone, I'm new to the forum, based in Ireland. I used to use a great professionally made oven which I used to cook pizza at a local weekend market but recently sold it as I decided to return to coprorate slavery. Now I'm "ovenless" and I'm starting a back-garden build in the coming months. I've been offered as much recycled refractory brick as I can fit in my trailer for free. Sounds wonderful but my worry is that it comes from a cement factory kiln. Surely this brick could contain some health nasties or in people's opinion, am I being over cautious? I've been reading people opinions on the hi-temp concerns, only use them for the dome not the floor etc, all makes sense. Just concerned about these bricks previous life...any thoughts welcome and thanks in advance!

[Gulf]

Sparkman,

Welcome to the forum. I don't think that you need to worry about the "cement factory kiln brick" being contaminated. They were used to make some of the very products that you will be adding to your oven's mortar. But, understand that they will a very high alumina firebrick and will be very difficult to cut. What shape and dimensions are your brick?

[Sparkman]

Thanks for the quick reply. Sensible comment "used to make some of the very products that you will be adding to your oven's mortar"- I hadn't considered that Anyway I'm hoping to get a look at them in the next week or so. As soon as I have dimensions I'll post again. Assuming they are basically impossible to cut with a normal grinder but of reasonable size, I was hoping I could just make sure that I had strong temporary supports in place while building the dome, "lean" the uncut dome bricks inwards against the support and fill the cavity behind/under each brick with some wedges of standard firebrick and cement. For the top of dome I thought I would just cut some standard firebrick also, i.e. the circular section at the very tip of the dome.

[david s]

Many kilns use insulating firebricks (very light). What you need are dense firebricks, heavy. I should think that the low temps we fire to (max 500 C) are way lower than the service temps of the kiln bricks so any volatile nasties shouldn't be a problem. A few hot burns before placing any food in it wouldn't hurt.