Sandstone floor?

[Dogzbum]

TLDR; can sandstone be used as cooking floor in WFO?

Hi, I have seen a couple of threads on forum about using sandstone for oven floor, but no definitive answer, and certainly nothing recent.

I bought inexpensive fire bricks which are tapered. To use them as flooring I'd need to shave off the taper so they sit flat.

I'm lazy. Cutting the tapers off is too much work and will blow out my build time. Aiming to be all done by end of 2020 (damn 2020, I hate it and need something good to show for it).

Have seen some suggestions that sandstone might be suitable for cooking floor (over the insulated base).

Has anyone had any success with sandstone?

[MarkJerling]

I think "some" sandstone may work while others would be to soft and porous to work well. Based on what I can find online, some will handle the heat well, others won't, so there's certainly a bit of risk involved.
I wish I could lay my hands on soapstone but that's unobtainium here by us. I understand soapstone makes a good floor.

These tapers: Can you provide some measurements? Would it not be possible to lay them in a sand base and so get a level cooking surface even though the underside may be uneven?

[Dogzbum]

Thanks Mark,

The bricks are 235x235mm with 75mm to 90mm taper. I'm thinking 15mm sand bed will eventually sag, which is why I'd have to cut tapers off. The cheap tile saw I'm using won't do that very well.

I can access solid, dead flat 40mm thick sandstone pavers easy enough locally but would have to travel to Sydney (from Canberra) for more firebrick.

I might do an 80mm sandstone layer and replace it with firebrick at a later stage if it splits or degrades.

[david s]

Sandstone does not stand up to high temperatures, don't install it.

[MarkJerling]

Thanks Mark,

The bricks are 235x235mm with 75mm to 90mm taper. I'm thinking 15mm sand bed will eventually sag, which is why I'd have to cut tapers off. The cheap tile saw I'm using won't do that very well.

I can access solid, dead flat 40mm thick sandstone pavers easy enough locally but would have to travel to Sydney (from Canberra) for more firebrick.

I might do an 80mm sandstone layer and replace it with firebrick at a later stage if it splits or degrades.

I have my whole floor on compacted casting sand, about 45mm thick. The whole idea being that if the fire bricks I've used for the floor ever fail I can install a new floor easily and if the new fire bricks are thicker than the existing ones I can simply have less sand and still have the top of my floor at exactly the same level. If the sand is compacted, there should be no settling, a bit like a brick paved patio on sand. I would not risk installing sandstone unless you know if that sandstone can handle the heat. Some sandstone will handle 1200 degC, but most will only handle 400 degC, and that's taking a risk with a pizza oven.

[Dogzbum]

Okay, thanks David and Mark.

I'll see how difficult it is to shave the taper off or I will do a 20mm sand layer and level the tapered bricks.

Not overly keen on bits of sand in my pizza anyway