pizza stone

14" unglazed clay tile. Less than 1 dollar at HD or Lowes.

I went to our local tile distributor and asked for a 12" non glazed terra cotta tile. When I asked how much they said "it's a sample, just take it".

Use a 12" non glazed terra cotta tile in ours

Home Depot has a couple of size options...
Example: 15" for $24.

Also have a 13.5 x 20 for around $28.
Order on line and pick it up at your local store...free ship.

14 inch is what we had. Works great. In fact Im looking for another one for the gas oven at home.