Is 2cm of slate thick enough for a real fire heart

[Anonymous]

As mentioned in a previous thread, I'm buying a cast iron fireplace privately and it comes with a black slate hearth which is 48 inches long * 15 inches deep which I think should be ok as it matches the size of the concrete base which currently exists.
However the thickness of the slate hearth is 2cm and I'm not sure if this is enough?
The previous owners only used the fire with a gas fitting, not as a real coal fire.
Does anybody know if 2 cm is thick enough?

Also, I've heard that with a marble hearth, you'd have to cut it into 3 pieces to allow for expansion etc.
Will this also be neccessary with a slate hearth?
If so, is it easy to cut slate and what kind of saw would you use?

 

[Anonymous]

Provided there's a concrete "structural" hearth underneath, there's no need for the slab(s) on top to be of any great thickness. I can't see any reason to worry about a 2 cm thick hearth.
I can't answer your question about cutting the hearth into several pieces. However, I also can't see why you would need to worry about a bit of expansion (unless the hearth is going to be tightly contained within a rigid enclosure, which sounds unlikely).
If it were my fireplace, I would install the hearth as supplied.

 

[Anonymous]

There are regs for hearth thickness these days as there seem to be for everything else, personally I would say 2cm is plenty but I'm not the man with a clipboard. As for expansion, even when my stove is at full pelt the hearth stays pretty cool as the stove pulls in cool air at its base for combustion, I dont know how much seasonal temp changes affect slate.

 

[Anonymous]

Something tells me that a hearth has to be 50mm of non combustable material. So as David said if there was concrete underneath it would be fine.

 

[Anonymous]

I shouldn't think expansion joints would be needed, but slate is very easy to cut - use a sintered or diamond disc in an angle-grinder (whch shouldn't set you back more than a tenner for a four-inch disk from hardware stores or machinemart.com/screfix.com),
If you're cutting slates to butt together when laid flat, cut at an angle so the edge is bevelled, with the top surfaces meeting and the bevel falling away beneath the slabs. If you don't like the very neat, straight cut the grinder gives, you can dress the edges before laying with a metal edge - I use an old billhook to roughen them slightly.