Calcium silicate Board

[Jakew]

Hey guys,

just started my first Pizza oven build. Building a 36” dome. For my floor insulation I have 3” vermiculite mix laid already. I’ve got some 2” calcium silicate boards to put ontop of that.
1. Will that be enough? Or should I beef up the vermiculite and add another 2” or so?
2. Do you just put a layer of clay then firebricks straight ontop of the Cal sil boards? Do you need the clay as they provide a level surface? I’ve been told to stop moisture getting to the boards. Would any moisture get to them for example cooking fats etc...some builders suggest foil?
3. So you run the boards under the dome walls? Do they have the support for the dome weight?
Sorry it’s a load of questions but I’m struggling to find direct answers to them.
Any advice welcome, thanks guys

[UtahBeehiver]

Have you downloaded the eplans from Forno Bravo, there free and many of these question are answered here or on the forum you just need to search the blog.

[Mongo]

As Russell wrote, most definitely get the e-plans and spend some time searching the forum. I have nothing going on this morning...

• The plans call for 2 inches of board but the consensus is now that you want more. I've read that 2 inches of vermicrete = 1 inch of board so you have the equivalent of 3.5 inches of board. 1/2 inch more than my oven.
• If you can raise the level of your floor without having it be too high and you have the patience to let the vermicrete dry out, wouldn't hurt to add more.
• Have you planned the height of your oven floor? Not too high nor low. Think about your back.
• The only reason you put anything between your bricks and the floor is to level the surface of your cooking floor. You don't want any edges to catch your peel. Never use mortar.
• Once you are there, lay out your bricks to see where you are. If perfectly flat - unlikely - you're done. You can float the entire floor if your bricks are wildly off or just float individual bricks. 50/50 sand/clay.
• Some say make a slurry, I used the mixture dry and just floated individual bricks as needed.
• Boards/insullation should go all the way to or past the dome. Don't want any part of the oven dome/floor touching a non insulated surface.
• Dome outside the floor, or dome on top of the floor - builders choice.
• I never cook anything in my oven that would drip fat unless it's over a pan to catch the drippings. Some use a 'tuscan grill' and rely on drippings being evaporated by coals. That scares me. I can envision seasoned fat getting on the bricks and soaking in and everything in the oven smells and tastes like barbecue. That's just me.
• Don't bother with foil. Even the thick stuff deteriorates and tears. I wouldn't cover the board with it. If it blocks moisture getting into the board, it will block it coming out.

[Jakew]

Perfect!! Thanks for taking the time to respond. Really appreciate the advice.