Hello, I am new here.

I have been building an oven for a few years, ( it’s almost finished ) and I wondered if I could get some feed back on my progress. I did two low temp. test burn fires, and then one high temp test. On the high temp test I was quite concerned about some of the exhaust gasses cracking thru a layer of insulating concrete. Nearly all of the smoke went out the chimney and the pizza baked in about four and a half minutes. But I was looking for perfection.