I was thinking the roof steel would be holding 8-10 bricks. The steel across the door will hold more. Going back to a drawing in post 101, the steel will hold what looks like a third or so of the oven ceiling weight (which goes up if there is concrete on top) and I guess the door too. Maybe some chimney weight also. 1/4 might work. I have no idea.
Traditional concrete is going to break up at oven temperatures maybe not the end of the world if you are just looking for mass, but the bags of quickcrete are not meant to get that hot.
Another design consideration that maybe you thought of...but if you build walls and then put the entryway steel on top, the front is no longer level with the back. Again, Im just spitballing because I'm not totally sure how you are building this.
Edit: the Flickr link was down so I didn't see the photo.
Thank you; these are all things I need to think about. I didn't realize how much weight would be on the doorway steel. I'll have to see if they have ½"next time I go.
https://www.traditionaloven.com/building/details/concretecladding.shtml had mention of the concrete cladding from that Flickr link. Interesting how he says to use concrete mix with Portland and lime. I did always find it strange how people use concrete over the walls and ceiling, since it's job would be to hold heat. I told your father in law story to my cousin last week. I use it as reference now for using concrete in heat applications

. That's a good idea about the firebrick turning on the side! So if I had firebrick walls and roof, would I be able to apply roofing right to the firebrick and I'd have to protect all firebrick walls from rain I'm guessing?
I thought about that yesterday as I held up the angle iron and was going to ask, but I forgot haha, so thank you for bringing this up! So to make it level, I'd need probably either brick or more mortar in the back I'm assuming? Another thing is that a downward slope to the back might be good for rain. Another idea is to use another angle iron on the back wall, to make it level with the front one. People don't usually use mortar with angle irons right?
Weird, Flickr said they are going through design changes on the site. Not happy with the timing.

I looked at Forno Bravo again and I remembered the FB blanket with wire mesh and insulating concrete over the blanket. Also they say "The oven enclosure must be sealed to protect your Pompeii Oven and its insulation from water. It can be constructed from concrete block, rebar and stucco mesh, metal stud and concrete board or free standing brick or stone. Basically, the style of the enclosure is up to you, your imagination, and the availability of local materials. The examples shown here from around the country will give you a start."
Jon,
The link is working again.
Peter
Thank you Peter! I have a feeling Flickr might be a bit unreliable over the next few days.