CaSi board suck water from mortar in first row of dome bricks?

[mrotter]

Just prepping for installation (need bit warmer weather). I have CaSi which will be placed under whole oven, dome walls will sit on it too of course.

Now thinking, CaSi will probably suck out the water from my refractory mortar which will be used for first row of dome bricks, right? How to prevent that? Should I simply place first row of firebricks directly onto CaSi board and use mortar only BETWEEN bricks?

[david s]

Paint some sealer on the calsil board to prevent the water being sucked out of the mortar. If the board is perfectly flat the mortar can be omitted between it and the bricks, just fill between the bricks. The floor bricks are best laid loose to allow for free expansion and contraction, the gaps will fill with ash.

[mrotter]

It is flat. Yes, I am perfectly aware of the baking floor itself, just talking strictly about dome/entry walls. I see.

The sealer could be some kind of a paint? Nuturally "fire resistant" paint? Or perhaps some thick aluminium foil (placed just under the dome wall naturally)?

[Gulf]

Just lay the dome brick flat on the CalSil. Mortar only between the brick. No sealer is needed imo. If you think differently, use vegetable oil or some other organic oil/grease. Please don’t use paint or anything else that you wouldn’t want gassing off in your food.

[mrotter]

Please don’t use paint or anything else that you wouldn’t want gassing off in your food.

Exactly my thinking, thanks. I will go the dry way or maybe oil way, thanks once more.

[ultrasport]

Very Easy fix. Just use Aluminum foil from the kitchen with
paper masking tape for the seams......works great !!!

[mrotter]

Btw, I already have my first row mortared. Even without any additional solutions (just bricks directly on CaSi board), I noticed no real problem with moisture sucking into CaSi.

Maybe it was because my mortar is cal-aluminate one and I did mix it more of a buttery consistency - no excessive water.