Then apply a tile and grout sealer to seal the grout.
Tiling a pizza oven dome.
Construction of an igloo dome does not necessarily require a frame if completed by a competent brick layer.
Tiles of different designs can be interchanged on same oven.
The dome itself a series of self supporting circular brick chains that curve inward until they meet at the keystone at the oven top.
Given the variety of colors and styles of tiles available at hardware stores the design possibilities are huge.
Then using a string and marking pen build a compass half the diameter of your oven 18 or 21 and mark the circumference of your oven floor.
To get a perfect shape dome put the sand in the shape of a dome.
It is to do with the sand and afterward place the bricks onto them.
These ceramic and glass tiles present a very convenient medium to finish the dome of the oven since their flexibility allows them to repeat the shape of the dome.
Reading through your replies to various comments it looks like glass or porcelain tiles are best to use and to use a thinset mortar to bond and grout the tiles.