Soapstone vs Firebrick ??

[deejayoh]

Re: Soapstone vs Firebrick ??

I realize this thread is a bit old, but I have been considering soapstone for my new oven build - and found this site that thought might be interesting to others researching the topic.

Soapstone Firebricks Fireplace Firebox Fire Brick :: M Teixeira Soapstone

Seems a bit pricy @ approx $10.50 per brick (for pick up) but it at least gives a reference point

At the end of the day, I suspect I will stick with firebricks - but I have a little while to research still.

[Hank10746]

Re: Soapstone vs Firebrick ??

Chip,
When I went looking for a stone for my oven, I found that the fabrication shop had tons of cut offs waiting for a home.. I don't remember exactly what I paid but it was less than $50 for 2 identically cut stones. The stones were cut to my specifications to fit the kitchen oven rack. I measured the interior of the oven and took 2 inches off of the width and depth of the stone to allow for air movement. If and when I have new ones cut I'll cut 3 inches off the depth, to avoid the little 45 degree cant of the back of the rack and cut the width a 1/2 inch narrower to sit between the wires of the rack. The current width is just the width of the rack wire too wide making putting the stone in and having it sit just right more effort than it needs to be.

John found his SS at such a low price that I remember that buying bricks would have been more expensive as a floor material. He found it on Craigslist I think I remember. Look around and if you want a SS floor I think you'll find it at a reasonable price. And I know that you could always make a fabricator a $100 deal to haul away plenty of cutoffs and patchwork them into a very nice floor..


Chris

Hi
I have just started collecting materials for a oven. bought 50 firebricks yesterday and ordered a 4.5 inch grinder and will be going tomorrow to get a sheet of 3/4" plywood and some cinder blocks. I would like to ask you if you would be willing to share information on the fabricator you got your soapstone from. I live in Hemet and I am retired and need a hobby. Just getting over having 2 hip joints replaced and will be at this for a while. I have been reading this forum for the three to four weeks since I found it. I have seen a lot of builds and have changed my mind 30 or 40 times since I started. Every time I see one I tell my wife this is the one and then I look at the next one and there I go again. Any help with materials will help also.
Thank you
Hank

[mrchipster]

Re: Soapstone vs Firebrick ??

Chip,
When I went looking for a stone for my oven, I found that the fabrication shop ...
Chris

Thanks for the info I will keep my eyes open for a deal and call a few fabricators in the area to see if i can be something going.

I really like the idea of fewer seams and a polished floor.

Chip.

[SCChris]

Re: Soapstone vs Firebrick ??

Chip,
When I went looking for a stone for my oven, I found that the fabrication shop had tons of cut offs waiting for a home.. I don't remember exactly what I paid but it was less than $50 for 2 identically cut stones. The stones were cut to my specifications to fit the kitchen oven rack. I measured the interior of the oven and took 2 inches off of the width and depth of the stone to allow for air movement. If and when I have new ones cut I'll cut 3 inches off the depth, to avoid the little 45 degree cant of the back of the rack and cut the width a 1/2 inch narrower to sit between the wires of the rack. The current width is just the width of the rack wire too wide making putting the stone in and having it sit just right more effort than it needs to be.

John found his SS at such a low price that I remember that buying bricks would have been more expensive as a floor material. He found it on Craigslist I think I remember. Look around and if you want a SS floor I think you'll find it at a reasonable price. And I know that you could always make a fabricator a $100 deal to haul away plenty of cutoffs and patchwork them into a very nice floor..


Chris

[mrchipster]

Re: Soapstone vs Firebrick ??

Thanks for all of the input I think I will buy a piece of soapstone in 1/2 and 1 inch sizes and try them in my oven, I like the idea of a half and half and if all works out I may do that at some point in the future, I will be making my inner arch 1/2 inch taller than ideal 63% to compensate for any future addition of soapstone.

I will work with my oven as a brick floor at first and experiment with some soapstone remnants and tiles

Again thanks for your thoughts.

Chip

[dmun]

Re: Soapstone vs Firebrick ??

I'd be concerned about a half inch of anything as the cooking floor. Remember, you're going to be throwing logs in, and levering them around.

[SCChris]

Re: Soapstone vs Firebrick ??

John, I was hoping you'd chime in. To date aside from the massive commercial oven, I think you'll be the first with SS as a dedicated oven floor. Regarding the mentioned cracking of SS in another oven, I agree, without more information it's hard to know why. I have a SS stone in my Kitchen Gas Oven and although I see a couple of cracks the stone still has structural integrity and it's been cracked for many months. The crack I have is right along a small talc vein. I know it's only a matter of time before my oven stone gives way. It's really important to point out that this stone creates a bridge over the kitchen oven rack and it doesn't have any support except at the right and left edges where it contacts the rack. In an WFO with a nice flat floor I think the SS will work out. Even if a stone cracks because it's not going to move much, I don't think you're worse off than the supporting floor. I agree with Dmun "see below" 1/2 an inch is to light to work well and I don't know that you'd get all of the advantages of SS.

Chris

PS The 3cm slab that I have sitting in my kitchen oven has made a world of difference in functionality of this oven.. Recomended!

[GianniFocaccia]

Re: Soapstone vs Firebrick ??

Chip,

What originally attracted me to soapstone was the seamlessnessness of it plus I was able to acquire polished, clear(?) slabs for $10/sq'. I am also intrigued with the effectiveness of the stone as a heating element apart from purportedly being optimum for cooking pizzas and flatbreads.

My concerns with soapstone long term are its ability to withstand cracking as seen in photos of another oven here on the FB site. I don't know if cracking is a function of talc veins in the stone or something else. My gut feeling is that the thinner the stone is, the higher its propensity to crack sooner. I am also curious to find out if bricks or tiles like you have would resist cracking more than a whole slab would.

Depending on the cost of your tiles I think your configuration is ideal. First off, 1/2" is not going to alter your entryway-to-dome-height ratio significantly. Realistically, anything between 60-65% is workable, IMO, and if you want, you could design your door height a tad lower in the event you decide you want to take your tiles out. Kudos for thinking of this prior to constructing your oven. Second, your floor insulation is fine. Third, you have the ability to easily customize your floor for whatever you're cooking that session (especially bread) by simply placing the tiles wherever you need them. I think a 50/50 firebrick/soapstone floor would make for a very versatile oven.

If it was me, I would cut the tiles to fit 100% of the floor leaving a 3/16" gap on the perimeter for expansion, build out your oven and give it a go. If any of your tiles eventually need replacing, reach for a spare and drop it in. Much easier to replace than a 100lb slab like mine.

What you gotta try is placing a soapstone tile horizontally on top of a couple of firebricks standing tall in your oven. I'm guessing this would make for a custom pizza pedestal and mimick a low-dome pizza oven beautifully.

John

[SCChris]

Re: Soapstone vs Firebrick ??

A thicker material will hold up better to the firewood in and out cycles. Also take note of the consistency of the product. The more homogenious the material the less stress fracturing due to dissimilar heat expansion you'll experience.

Chris

[mrchipster]

Re: Soapstone vs Firebrick ??

I found some 1/2 inch thick X 12 inch X 12 inch soapstone tiles and am considering putting this down on top of my 2.5 inch thick brick floor.

I have 2" of vermicrete under 2" FB insulation Board so I am well insulated in the floor area.

I have not built my arch yet and want to compensate the inner opening to compensate for the added thickness should I decided to add the soapstone.

Does anyone have any comments on using this approach?

Chip

[SCChris]

Re: Soapstone vs Firebrick ??

It's come to my attention that Ovencrafters doesn't recommend Soapstone for bread ovens because of the higher heat conductivity when compared to the standard Firebrick floors.

I can see how this additional conductivity can really help in a commercial pizza oven where you're moving pizzas as quick as you can build them. Even in our ovens this can be an advantage.

I don't know if Soapstone is a real disadvantage when we're baking bread in our Pompeii style ovens. I would expect that the crust would cook faster. Is it too fast? Can this be mitigated somehow? I bet it can be mitigated. Foil or ceramic tile or a pizza stone on top of the stone and under the bread loaf or whatever else might be all it takes to be just right.

I would also expect that the oven deck would heat faster and the overall temps would even out faster. This would seem to be an advantage.

When I have baked on the Soapstone "pizza stone" in my general "inside" oven I have adjusted the baking by not running the oven to 550f and turning it down to 450f after putting the bread in to bake but just running it to 450f and leaving it there. The additional mass and conductivity of the stone seemed to make this a prudent change and it turned out being just right.

I think the idea of running the oven to 550 and backing it down goes along with the poor performance of standard ovens. Once the oven door is opened and by the time you get the bread in and steam going you lose a lot of heat.

I?ll be trying a 3cm 20 by 16 inch piece of stone in the oven to bake on and see what happens.


Chris

[lwood]

Re: Soapstone vs Firebrick ??

You should be fine with the granite entryway. Mine doesn't get that hot. It's kinda interesting, there is like a wall of heat as you put your hand inside the oven. It's so hot you can't put your bare hand in past it. That occurs, in my oven, right where the dome begins (not surprising). Out board of that heat wall you can easily put your hand (maybe <300F). That is where I will begin my granite entryway slab. It's actually a great place to keep things warm. The granite, is a good choice for that area and it comes in lots of colors.

[SCChris]

Re: Soapstone vs Firebrick ??

At this point I have SStone in the entry area of the WFO. I really like the non-stick and stainless properties of the material. I'm not so wild about the blue cast. This is really an aesthetic rather than functional thing. If the area had some complementary color in the area, I'd be fine with it, but my area colors really run toward the reds and browns. I have felt since I put the SStone in that the efficiency of the oven was somehow less than the measurements I had early on, but I couldn't, didn't have the measurements.

I'll swap the entry for the same Granite I'm using on the surrounding work surfaces. I would have gone directly to Granite, but I didn't have a good feel for the ability of Granite to hold up in the entry. At this point I feel like, what do I have to lose?

In the oven, if I go to SStone, this is not a given, I'd add an inch of rigid Calcium Silicate insulation board and then put 3cm SStone directly on this. I need to think about the entry / oven transition. I don't think putting an exposed inch of insulation board is really the way to go and going back to Fbrick as a thermal break here could be the answer.


Chris

[lwood]

Re: Soapstone vs Firebrick ??

I think those numbers are close enough for our mental gymnastics. The heat capacity of soapstone is 14% higher than firebrick. So you are able to store more energy (by weight) in soapstone than you are in firebrick. That's a good thing.

Were you planning to put firebrick under the soapstone then insulation? If installed that way you reduce the thermal conductivity to that of the firebrick. Cause the soapstone cannot loose heat, to the outside, faster than the firebrick. The firebrick is a heat stop of sorts. I think you get the best of both worlds with that configuration.

[SCChris]

Re: Soapstone vs Firebrick ??

I had a stone cut to size to put in my gas range and can attest to the “oven spring” aspect. I replaced an aged Trader Joe’s pizza stone and cleared out some “jury rigged” porcelain tile. Most of this junk was meant to provide mass and buffer the internal oven temps, and they did. I have to say that the 3cm stone really changes the personality of this oven for the better. It seems like the oven has a quicker recovery to temp time and that seems logical given the greater T. mass and higher T. conductivity.

I wouldn’t want to say that a standard oven could compete with the WFO, these are very different creatures. What I will say is that today’s standard ovens have been diluted over time to be barely acceptable and the additional mass that this stone goes a long way to bringing my standard oven back in line.

As for the above numbers, it’s hard to divine exactly what they mean. How fast can the pizza dough or bread or whatever take up the additional heat transfer the Soapstone can provide? How much difference does the thermal capacity of 3cm SStone vs Firebrick really make in our WFOs? What exact material was measured and how does that relate to what we’re using?

Chris