Applying Mortar in the Joints or Voids after removing the foam form

Can someone please clarify. On this forum, people say it is okay to patch mortar joints inside the oven as long as it is done before any firing of the oven. However, in the directions from the company, it clearly says DO NOT patch any mortar joints as they will not adhere and will fall out into the pizzas.

Okay, I can see where that would be confusing. The problem with offering guidance on this topic is that your finished oven is going to be unfired for a relatively short period of its life. Most people notice gaps only after they’ve done a few fires because the soot that lines the bricks makes gaps obvious. So the general rule is that you should not try to fill gaps in the firebrick with more mortar, because new uncured mortar will not adhere to cured mortar.

Before you fire for the first time, you can fill gaps. Consider it a one-time chance.

This is @BrickWood ‘s FAQ on the topic. It comes from BrickWood itself and should be considered as advice from the designer.

Hope this helps!

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BBM is Spot On!

When we first started making the forms, those joints (ridges on the foam form) were MUCH LARGER. I’ve since trimmed the height of those ridges to 1/8"… If so inclined, you could also smash that ridge down w/ your thumb (before applying the fire brick)… or sand them off w/ sand paper.

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