Can I use Granite for floor and dome

[I Love Pizza]

In my home town I have an opportunity to use pink granite to build my oven with. Could someone tell me the pro's and con's to using granite. Your experience and comments are greatly appreciated.

Thank You

[Xabia Jim]

Re: Can I use Granite for floor and dome

Sure, why not? What are some of the sizes you're thinking about? Slab thickness? Dome block size? etc.

Many ovens were first made of stone and mud.....whatever you had locally.....now we have high tech firebrick and insulation....but many of the old ovens still stand. I've seen many rough stone ovens and even some thick slab granite ones.

Granite is an igneous rock which stands up to heat. Worst case is the slab might crack....then patch it!

Now what about heat retention? Might want a good insulation layer for pizza as it's a pretty dense rock.

[taiwanpizzaman]

Re: Can I use Granite for floor and dome

I spoke to a kiln builder about using granite as a floor slab, because there is a guy here who also wanted to use granite and he reckons the slab would definitely crack and pieces would chip off. Apparently they use heat on granite to chip off pieces as decorative stones for walls or pathways. I've read granite absorbs heat very well but cannot withstand high temperatures. Why not find a granite supplier and ask them? I would rather make sure if I were you, once the oven is built there is not much you can do with a cracked or broken hearth floor! Cheers!
Colin

[oventhusiast]

Re: Can I use Granite for floor and dome

Yikes! If you do, You'll be sorry!
You can use a propane torch to 'pop' chunks of granite right off of a high point on a slab. I think you'd be pulling chunks out of your pizza crust along with your teeth! Go with the fire brick or a precast floor!
Best to you,
Rick

[dmun]

Re: Can I use Granite for floor and dome

Go down to your local stoneyard, and see "flame finish" in action! Bring your safety glasses.

Now, in fairness, I think the surface popping comes from intense heat, and water from outdoor storage. Why not put a couple of slabs and blocks in your fireplace or bar-be-que and see what happens?

[Hendo]

Re: Can I use Granite for floor and dome

David,

You always seem to come up with a simple yet practical way to test a theory!

Like suggesting to a couple of us, who doubted Cal Sil's ability to withstand the weight of the oven dome, to get a brick and stand on it. (I'm convinced on that score, by the way - I actually ended up standing on a board on only a 4" x 2" bit of the stuff and absolutely no compression whatsoever!)

Thanks for being there!

Cheers, Paul.

[CanuckJim]

Re: Can I use Granite for floor and dome

During the masonry season, we use the flame technique frequently, but with acetelyne, not propane, because the latter is not hot enough. Same torch setup a plumber carries.

We cut a lot of stone, and where the cut faces show, we pop them off with the torch. The degree to which this happens has to do with how long the stone has been out of the pit and whether it has been exposed to a lot of rain. If the stone has been sitting around dry for a while, it's much a much more difficult procedure. What's happening, I think, is that the residual mositure is being heated to the boiling point.

Commonly, we do this with sedimentary rock. Not quite sure of the extent of the effect on igneous rock, though, but I imagine it would be similar. Despite its density, igneous rock also has seams that I don't think would react well to intense heat and thermal cycling. However, it has been used for oven floors historically, so maybe we're missing something.

I'd definitely do a test piece before installing anything.

Jim

[I Love Pizza]

Re: Can I use Granite for floor and dome

The pieces I have available to me are 10"x7"x4" they used to be part of a street in Minneapolis. That being said, I do not think they polished these particular pieces. I figured since they where so thick it could be done, looks like I would have to dry them as much as possible before subjecting them to very high heat. I can pick up these pieces for $2.00 a piece and thought they would make a very nice looking oven. Now that you all have this information (that I should have included before) does this look viable?

[CanuckJim]

Re: Can I use Granite for floor and dome

ILP,

The price can't be beat. I'd definitely go for it and test the stone. I've been using street cobblestone that was laid down in about 1860, some of it granite, and it's almost impossible to cut or split. Harder as Coop, the cabinetmaker, says "than the hubs of hell." Seems you'll be in the same position. Be very careful if you rent a brick saw with a diamond blade, because the granite will chew the blade up bigtime, and you'll be left with a hefty wear charge. Do, please, be careful with such a hand-held saw; it can be ornery. Wear a mask.

Personally, with such hefty stone in decent sizes, I'd map out a decorative pattern (star, hexagon, something), and if the stone is stable enough, I'd damn the expense and use a design I liked for the floor. You're only going to do this once, so why not try it? Downside is you've lost twenty bucks and some labor. If your cutting is good (90 degrees true), you can butt the pieces without mortar.

Even if it doesn't work, why not buy enough to do a portico in front of your oven? All you need is some decent gravel, compacted on a stable substrate, and you're away. The joint fill could be crushed limestone, sand or mortar, your choice.

Polishing will be labor intenstive, but there you are. Sometimes called "sweat equity."

You've got an excellent historical source. Use it.

Jim

Jim

[I Love Pizza]

Re: Can I use Granite for floor and dome

Thank you so much for the info, I was hoping for a positive answer I REALLY want to give this granite a go. As far as the saw goes maybe I should rent the saw and purchase a blade, do you think it will take a beating worth purchasing a new blade? Or should I just pay the wear charge?

[CanuckJim]

Re: Can I use Granite for floor and dome

ILP,

I'd buy the blade, because you might end up paying that much for a wear charge. Besides, you'll be using it to cut brick and lots of other stuff during the project. Makes sense.

Jim

[dmun]

Re: Can I use Granite for floor and dome

As far as the saw goes maybe I should rent the saw and purchase a blade, do you think it will take a beating worth purchasing a new blade? Or should I just pay the wear charge?

Do not pay wear charges, particualrly if you are sawing big chunks of granite. There are two kinds of diamond saws in the 10 inch size. The smooth rim one for 35ish dollars is made for tile, and will cut some brick, but it isn't sintered all the way down what looks like the diamond layer. I've been through three of them so far. I like them because they are safe, you can run your hand on the running blade without damage, and I like to work close and personal to the blade.

The good ones are 100+ and are segmemted. This may be what you need if you are cutting belgian blocks or equivelent. These should be treated like a circular saw blade, keep your hands away from it.

Needless to say, you want the ten inch wet saw, with the water feed tube, and the moving table. This has a strong enough motor to cut big blocks.

[dmun]

how NOT to cut a belgian block

See enclosed picture: cut four full depth cuts with a seven inch tile saw, break block, (easier said than done) mortar it in where everyone can see it.

[taiwanpizzaman]

Re: Can I use Granite for floor and dome

I thought I'd let you know, I also have a 4" thick by 5" deep pink granite slab by my oven landing. This weekend I made an "aggressive" fire and the radiant heat from the firebricks cracked the slab in half and since the entire oven is on top of it, there is nothing I can do