42" Build in Tennessee

[Bocktn]

Hello all FB participants. In the beginning stages of a 42" build so I've been scouring this site for useful information. I must say, there is an overwhelming amount of information here. So much so it makes a guy wonder which approach to entertain. I will be building from an area adjacent to a "back porch" off of my garage. Foundation will be standard in that no out of the ordinary efforts will be required. While I have the basic oven design in cad, I am still toying with the venting structure.

I do have a question for the craftsman who venture before me...when setting the dome's first row, is the preferred location outside of the floor or on top of the floor? I see that it appears both styles are used.

A huuuuge thanks to all who have boldly went before me as I hope to reap the benefits of your losses as well as your gains.

Bock

[UtahBeehiver]

Dome on top of floor is easiest, you can be less precise on the floor cuts, leaving floor a little proud. Floor inside requires detailed and time consuming brick cutting, I did and not sure it is worth the effort. Some school of thought it is easier to replace a floor brick with floor inside dome but in the hundreds of builds I have seen I can only think of maybe one needing to replace a brick. If you are enclosing the oven I would go with dome on top, If not, builders choice. BTW, what part of TN, have family near Nashville

[Chach]

Like Utah said it's the builders choice on that. I did an enclosure and I still cut the floor brick on the inside. Just my preference because in my world if I didn't I'd have to take that one out one day LOL. Yes there are many cuts but wasn't bad with the brick saw plus you will get the feel for using the saw on these.

Ricky

[Bocktn]

Thanks for the responses guys. As of now I am planning to go on top of floor. It will have a cover built over it in the end.

I hail from Kodak, just west of Knoxville near Douglas Lake.

I'll start my narratives and picture submissions soon. That way I'll be sure to get the added responses of the "yikes, don't do that", Maybe even before it's too late.

Bock

[JRPizza]

I built my dome on top of the floor bricks. My insulating board ends right at the OD of the brick dome (to conserve on how many boards I needed) so I thought I might slightly lower the bearing stress on the edges by building on top of the floor bricks, as the weight of the dome might be dispersed over a slightly larger surface area. I don't know if it mattered but that is what I was thinking at the time.

[Bocktn]

And so it begins. On top of the concrete deck, beneath the fire brick floor...what is the "new norm", is...FB board, casi board, vermicrete or a combination? There seems to be an abundance of ideas on the base build.

[UtahBeehiver]

The new norm would be high tech insulation such as AlSi board or CaSi board, also the most expensive and prone to absorbing water so you need to address water ingress and egress. This can be minimized placing FoamGlas insulation as first layer (does not absorb water) or raise insulation off hearth surface with spaced ceramic tiles with weep holes in concrete hearth. If budget is an issue, the p or vcete is an option (just requires more thickness) as well, do not use fiberglass or rockwool insulation or polystyrene on your oven, not suitable for various reasons.

[modified9v]

If I had it to do over again I would have put the dome on the floor and I would have extended the floor out a little extra for load reasons. I used FB board and I wish I would have sealed it with Red Guard right off the bat. That board hates moisture... even heavy dew. Best of luck.

[Bocktn]

Thanks guys. I plan on foamglas bottom layer, cf on top. Next, I guess preference selection, is the floor height of the oven. In looking at most of the pics, I am guessing these are hitting somewhere in the low to mid 40" range. I am wanting to be in the 50" to low 50" range so as to not be bending so much while looking in. See any issues with that? That would mean at least one more row up on block in my case to 5.

[Chach]

There is no issue other than preference. I made my height where i could see in without squatting down but still comfortable to work the oven. This was around 48 1/2" I am happy with that height.

Ricky