New here, but reading and researching for a dome pizza-oven long time … At last, i’m building, but have some questions. I have the materials (Perlite, blanket, heat stones, chimney etc etc) and a strong base. On the base is a box (4 planks). What should i put in the box?
- first a heat-blanket
- then perlite/cement
- In the perlite cement i want to put (push) stones in a herringbone-pattern.
My two questions are:
Is 1) necessary? What should i put on the bottom of the box?
About 3) Can i put the stones in the wet perlite/cement or should i do this in a different way? (first drying, than sand?)
Hi PizzArt, and welcome to the BrickWood forum.
Your goal is to have a stone hearth (cooking surface) rather than a firebrick hearth, if I understand that correctly.
The BrickWood designs call for dry-fitting brick in a herringbone pattern. A layer of sand underneath is used to level the brick without the use of mortar (very important!), and the Perlite/Portland layer is used to insulate the brick hearth layer from the cold concrete base.
If you do mean “stone” rather than brick, and your stone has irregular shapes, I’m not sure this would work out for you. The dry-fit brick has little to no space between each brick, but stone would need some way to fill the spaces, which is beyond my current knowledge.
So, if you are actually building a firebrick hearth, the answers to your questions are:
- No, you don’t need a heat blanket. You do need a layer of reinforced concrete to bear the weight of the oven. If you are not following the BrickWood method of casting three reinforced concrete slabs with space for the hearth, you can search on the forum and find a number of threads from builders who have cast their slab in a single piece on top of the base.
- And, no, the firebrick must not be “fixed” into wet cement or otherwise constricted. They need to “float” to allow for thermal expansion and possible replacement of a broken brick in the future.
I hope I understood your question correctly, and please do clarify if there’s anything I misunderstood about your plans.
It is indeed ‘brick’, in my own language we use incorrectly ‘stone’ for bricks.
And your explanation makes sense: the bricks need to be ‘floating’ because of the expansion.
Thanks for your reply! I hope we can be helpful as your build proceeds.