Hi, I am building a pizza oven.
Its has been built out of kiln brick and I’m adding 2 inches of ceramic fiber blanket attached with chicken wire for added insulation.
My question is, What cement do I use with what other ingredients “ie” sand to get the right recipe so it will hold up and not crack and fall apart?
Thank you.
Hi and welcome to the BrickWood forum!
It sounds like you’ve picked up some tips here, and that’s great.
We use Type S mortar as a stucco to cover the insulation. A first layer is used to cover the chicken wire matrix—it will not completely nor evenly cover the insulation or wire, but that’s fine. A second layer is used to form a shell over the oven, and many builders will do a third, finish layer to complete the form.
Whether you do two layers or three, use a wet sponge on the final layer to smooth out the stucco. When it is completely cured, you must apply a thorough coat of outdoor deck/floor paint to seal the stucco.
Applied in this manner, it is very unlikely to crack thanks to the matrix over the insulation. It needs no additives. Do not use concrete for this purpose; the aggregate and additives are actually more likely to promote cracking.
A few builders have used wet stucco pre-mix from a trade outlet, but I don’t recommend the extra trouble and expense. Type S mortar is cheap and does the job nicely.