Can I put brick on top of ceramic board?

[Merula]

Noob question! I felt it was more convenient to put the square of the ceramic board down and build on that rather than cut out the shape of the oven. Is there any problem with putting bricks on the ceramic board?

[RandyJ]

You want the whole oven on top of the insulation. So it is fine if you just leave it square it doesn't need to follow the shape. People just do that so they can save material. Otherwise you are just fine.

[UtahBeehiver]

I am assuming you are enclosing the oven, then leaving the CaSi board "proud" is not an issue. As Randy J said, not only the floor but the dome needs have insulation under it. I don't believe you are talking about concrete board but rather CaSi refractory board.

[Merula]

Thank you. I thought it was a noob question and already cut the shape as I felt that the ceramic fiber board was a bit too spongy for the bricks.

[Chach]

omg im such a dumb dumb i thought it said cement board it said ceramic lol my bad i probably should get more sleep...yes i totally agree with these guys. I am enclosing mine so i didmt cut the shape of the floor

[UtahBeehiver]

Spongy CaSi board? Do you know what the compression strength of the board is? I should be at least 75 PSI with 5% compression. There are some materials out there with lower compression ratings.

[david s]

Spongy CaSi board? Do you know what the compression strength of the board is? I should be at least 75 PSI with 5% compression. There are some materials out there with lower compression ratings.

The calcium silicate board I use does not get spongy when wet. It’s compressive strength is unaltered. I found this out recently when we were flooded. The calsil sucks up water incredibly, almost 4 x it’s dry mass. Other products can get soft and spongy when wet.