Pizza oven fire brick and mortar

[Rosy]

I got my fire brick through Interstate Brick. I ordered my brick through a friend who is a brick mason, on his account to get his pricing. I found that by using the yellow fire brick you can get these for $2 /brick. The other colors are $2.40 per brick. I bought enough brick for my pizza oven dome, 42" inside diameter, and bought just enough fire brick brick of a different color just for the opening. The yellow brick, when finished will only be seen from the inside of the oven. I also used a clay mortar + Portland cement and silica sand for my mortar instead of the commercially prepared refractory mortar which was $85 per bag. My brick mason said this is the type of mortar he uses when he make pizza ovens and has made over one dozen ovens so far. All of my mortar is less than the cost of one bag of refractory mortar.

[MarkJerling]

Hi Rosy
Welcome to the forum. Regular cement mortars cannot handle the extreme heat of a pizza oven long term. Many members use the "Home Brew" formula, which works.
Read more about it here: Refractory Cement - Forno Bravo Forum: The Wood-Fired Oven Community
Unfortunately, yes, refractory mortar is expensive. Your "clay mortar" recipe appears somewhat similar to the "home brew" recipe. What are the quantities of each component in your mix?
Kind regards,
Mark

[david s]

Proprietary calcium aluminate mortars do not recommend their use for thick mortar joints. They are not suitable to fill the large spaces on the outside of a WFO brick dome. I believe that this is because of the possibility of steam spalling. If using either a calcium aluminate based mortar or home-brew mortar it is therefore advisable to add some burnout fibres which will give the thick mortar joints a measure of protection from steam spalling, provided the temperature is ramped up slowly. The downside is that they take quite a bit of extra mixing in order to disperse throughout the mix. They have a tendency to clump together.