I have a Zanussi commercial gas oven... probably 15 yearas old but in good condition....and it cooks unevenly. Am wondering if placing a pizza stone or fireplace bricks on the bottom will help even out browning and cooking? The burners are at the bottom and run in a double row from front to back in the centre. Dont, know if it is possible to put a pizza stone / firebricks on the base of oven? Will this damage the oven or be dangerous. Has anyone done this before?
Bricks in the oven are an old breadmaker's trick. They do increase thermal mass, and thus temperature consistency. I've kept 3 regular, not fire, bricks on the bottom shelf of my gas oven for years, and they work well. Plus they're always handy when I need to press some eggplant. If you go with something other than firebrick, you need to be sure the things are real clay all the way through. There are modern composite 'bricks' with a clay coating over something else. Those'll likely break if you bake them. The way to tell if a brick is solid clay is to break one in half and have a look. Whether regular brick, or fire brick, the first time you heat them up, you'll want to do it slowly. Say 80°C (175°F) for a couple hours before heating above boiling. That'll minimize chances of potentially violent cracking.