Block Stand Question - Pompeii 42"

[Yeager]

Hi Beagle,
I did buy the traditional insulation board from Smith-Sharpe (They are great to work with), but that product is not very happy about moisture. The idea behind the foam glas is that it elevates the insulation board so it doesn't wick in. I can get close to the same effect by placing thick plastic between the insulation board and the concrete stand, but having it a couple inches in the air under foamglas (which is not moisture sensitive) would be cool design.

thanks,
Yeager

[the Beagle]

to Yeager,
Smith-Sharpe Fire Brick Supply at 2129 Broadway St NE has insulation board suitable for placing beneath the oven structure. I bought some last week. It is a bit pricey but eliminates your shipping issue as being available locally. Call Susan at 612 331 1345

[Yeager]

Hi Randy,
Thanks for the comments! I am going with 2 - 2" Insulation Boards. I would prefer to have one of them be foam glas (avoid any moisture issues), but can't find anyplace to source in the Twin Cities (without paying for major shipping!). Am thinking of putting plastic liner between insulation boards and the concrete stand. I would go with your block approach, but am already pretty high (I went with 5 block height stand). I did toy with the idea of putting down insulated brick instead of one of the insulation boards (still can!) - thoughts?

thanks,
Yeager

[RandyJ]

Hey Yeager I think you plan looks nice. Looks like you have planned for a 1.5" revel. That would work nice with a 1 " flange on the door. How much insulation did you decide to go with under the oven? I can't wait to see your oven go togather.

Randy

[admin]

Yeager,

We just completed the migration to the new server, so you may have been in the middle of that - I posted a test above and the thumbnail opens to the larger image. Please let me know if you have any other issues.

Mitch

[admin]

Testing

[Yeager]

somethings weird going on with fornobravo site. It is only storing/viewing a thumbnail. Attached is the image saved as a PDF! Hopefully this works better.

[JRPizza]

Yeager, your screen shot is so small I can't make out any detail, even if I try to magnify it.

[Yeager]

Hey All,
Getting ready to start with my dome! (Winter is finally letting go!). Attached is my current set of plans. It is a 42" interior with The dome not sitting on the brick floor and a 4" thick of insulation board. Would love any comments or thoughts that you have. I am least comfortable with the opening/arch. I tried to set the flue on center right after the apex of the floor/door. And have a 1" lip for the door to rest against. Let me know your thoughts! (you won't hurt my feelings!)

thanks,
Yeager

[RandyJ]

Hey Yeager for the saw I went with the harbor fright one with a rigid blade. That worked great for me and a lot of others as well. As for the over hang I would think you will be just fine, but a little thicker might look cool as well. My over hang is about 12" roughly and that lip is 6" thick. But if you cast it all as one pice I do not think you will have any trouble.

As for starting now I do not think you have a chance to finish before it freezes. Unless you have unlimited time at your disposal. I hit mine as hard as I could and it still took me more than a month to do, and I do not think we have that much time till it freezes. I do not know how long you want to keep it from freezing after you lay the bricks. Just because it is set it is not cured.

Randy

[UtahBeehiver]

In addition to the floor heating break I did a.semi heat break on the chimney arch by tapering the inner face so there was minimal surface contact with inner archer then stuffed gap with ceramic rope then high temperature caulk.

[Yeager]

Hey Guys,
Sorry for delayed response - been traveling a lot for work. Getting ready to pour the "table top" on my stand. I am "planning on pouring a 4" slab with a 8" overhang using qwikcrete 5000 with a lot of re-bar reinforcement.

Is a 8" cantilever too much? I am not for sure if making it thicker (i.e 5" thick would be better for that cantilever profile). Attached is a CAD drawing of what I am planning. It is mainly for aesthetics.

Russell - that is one of the prettiest layouts I've ever seen!!

Couple questions that's been brewing!

Heatbreak - For the "heat break" doesn't the hot bricks eventually touch "some" of the concrete if it's truly a flush floor? Russel, is your heat break the piece of metal looking item? It has a bricks on outer left and right that still touch. I may be in left field here - sorry guys!

Dome - Been starting to think about building the dome. Only have another few weeks before it's regularly freezing temperatures, so may not be able to do much unless I tent the oven and have a heater! For making the dome and cutting the firebrick is there a saw that you recommend buying? For the first few rows I believe it's firebricks cut in half (4.5") with a slight angle on each side. Is there a predictable layout of firebrick size (they seem to get smaller as you approach the top) and angles of the brick? I thought maybe I could maybe rent a good saw and cut a bunch of the firebrick to have ready.

thanks,
Yeager

[UtahBeehiver]

Yeager,

I elevated my CaSi insulation by placing FoamGlas insulation (which has thermal conductivity properties similar to CaSi) underneath which is water proof and would not absorb moisture. But there are lots of ways to skin the cat. As you know CaSi gets mushy when it gets wet.

[RandyJ]

I would say that how much insulation you use is a part of your buget it will cost a little more to buy the board insulation, but it is a lot easier to install and faster. That said I don't see many going much over 4" but 3" would work too.

You will want the entry at the same high as the floor. IT can be a little hard to picture it in your mind I poored a lip that stuck out the front to hold the vent and still had a few inches of cf board to finish the heat break.

Randy

[Gulf]

Here is some reading for you on some past builds on this forum with Super Isol ? (Calcium Silicate). I would use at least 2" of the board unless it is placed on top of a few inches of v/pcrete. Some of the recent formulas for CalSil are a little more water resistant than that in some of the earlier boards. You will need to check the specifications of the particular insulation that you intend to use. The CalSil that I used did not have those additives. I took great pains to keep it dry. But, it will dry out if it does. I would elevate the insulation. I think that RandyJ 's idea will someday be the norm .

If you want to have a level hearth with the pizza cooking surface, how do you avoid the firebrick from transferring heat to the concrete hearth? Do you need to airgap it, put in a special grout?

Can you explain that question a little more?