Dogshark58 Build

[mongota]

I have just cut my ceramic fibre board to size, it may have excellent insulation but I’m not impressed with the lose debris on the edges. I had read that painting Red Guard under the insulation is advisable especially in a wet climate like Ireland. Would painting the edges of the fibre board help in sealing the loose debris on the fibre board edges?

I did that on mine ONLY because of the design of my oven. My hearth slab outside the footprint of the dome is exposed to the elements and I didn't want rain saturating the slab, and then moisture from within the slab migrating up from below and into the insulation. For my build, the RedGard has worked out very well in terms of preventing water intrusion into the floor insulation from the hearth slab. But it's not a detail that needs to or should be included on all builds.

Best, Mongo

[mongota]

13-1/2" is what I used on mine. I have a 42" oven, the landing is 13-1/2" deep. My landing arch dimensions with regards to the transitioning to the chimney anchor plate and chimney itself are in the link below. I start my fires on the landing and even after years of use there are no smoke or soot stains on the face of the oven opening. It draws quite well.

https://community.fornobravo.com/for...961#post431961

[rsandler]

On my first oven, I just used a piece of cardboard to make the break; of course this eventually burned, leaving ash (a reasonable insulator) filling the gap. On my second oven I had a bunch of Nomex felt from my attempt at a door and placed that in the gap (though again the top mostly filled with ash). Either way, 1/8-1/4 inch is typical. Whatever you fill it with, you'll want the gap to go all the way down to the insulation, as the bricks don't only conduct heat at the surface.

[Giovanni Rossi]

These links may help

heat-break-to-do-or-not-to-do

thermal-breaks

I've always liked Mongo's ( mongota ) approach.