Material advice for an oven build?

[TorontoJoe]

Hi Gang. This is my first post here. I've known of this forum for a long time and members here seem really great. I've actually built two ovens in the past (not my own) and both times they were barrel style. I'm pretty handy with concrete. I finally decided I need a small oven in my back yard but unfortunately have to do this on a tight budget. Brick is not an option for me. I decided I'd give one of these full cast gym ball types a try and maybe only do fire brick for the floor. I hope someone can assist me with some questions:

Mix for dome.... I've seen guys on YouTube doing domes with nothing but perlite and white portland, reinforced with steel mesh... Sounds interesting but I'm in Toronto, Canada. I don't know if this would handle freeze/thaws very well... Is this a good option? Does anyone know how much pertlie and portland I might need... if it is?

I've read here that a 3;1;1;1 mix is good for a cheap, reliable recipe. Is this the general consensus now? Should I be looking at this as a better option?

Sand and white poltland is an easy find but does anyone know where to source builders lime and clay in the greater Toronto Area? I'm not even sure what sort of clay and lime is being referred to.....

For this size oven would anyone know recommended quantities of these materials? How much of each?

Once the dome is built and everything in place... I'd rather leave the dome rather than cover with a housing and insulation.... What would be the recommended product to seal and protect the dome to ensure water doesn't get in and cause it to crack in winter? (I still plan to cover it in winter for some additional protection.)

Can the oven floor be poured out of this same 3:1:1:1 mix or is fire brick a necessity? I'd rather pour than use brick if I can as I have more skill with concrete.

The base - on the last builds I did I poured a slab over sand then formed for a wall and platform in one pour. It worked perfectly... but it was bloody hard work! I was thinking a steel frame might be nice. I'm ok with my welders but for ease.... I'm curious if anyone knows... The steel bases Forno Bravo sells for their Prmiavera....

https://www.fornobravo.com/store/pri...or-pizza-oven/

They're quite inexpensive. I don't think I could make one for what they sell them. Does anyone have any input on the quality? Do they even sell them separately?

I appreciate everyone who contributes to this forum. Great work all!

Here are a few pics of one I built before for my father in law. It's not perfect but it made some nice pizza and bread. Mostly used clay brick and scrap marble... not quite finished here. I wish I had the space at my house and could afford the materials to do something like this again.... or even a brick dome... but it's not possible for me.

Thanks everyone!