limestone fire surround

Dear All,

I recently bought a limestone fire surround (which I am yet to install), and when I asked if it was suitable for use with a real open fire, I was told by the vendor it was.

Recently I have heard that the way you can tell if a fireplace is suitable for real fires is if the herth is in three parts, with the joins aligned to the aperature of the fire - I assume this is for expansion? The fireplace we have bought (as suitable for real fire) has a single solid slab of limestone for the herth.

Basically, am I screwed? Can I use the solid slab as a herth, or have i been sold a dud? It is a fab fireplace though, so I'll bet the missus would use it is an excuse to stop me having fires :-(

Any advice appreciated

The technical term is 'slabbed and jointed', and yes, your hearth should come in three pieces all joined together, and the surround should be slabbed and jointed in three pieces similarly ( if you have a stone surround ).

What sort of fire have you got? Is it an open fire basket shedding ash onto the back hearth just behind the superimposed ( limestone ) hearth? I think that would be the worst situation, as the heat from the basket will be very near the hearth.

If you have an arrangement where the fire can't 'see' the hearth so well that might let you get away with it. Do you have a fireplate? A fireplate is a strip of metal (usually brass ) embedded in the hearth directly in front of the grate. It will be the width of the fire aperture and maybe 5" deep. A fireplate keeps hot ashes and cinders off the superimposed hearth. Having one of these too might help.

The problem with open fires is that the heat output can exceed the 3kW that a standard gas fire can put out, so the hearth may be apt to get rather hot, though I have a Jetmaster woodburner inset firebox and haven't found the hearth to get terribly warm. You might also have less chance of it cracking if you have a log fire, especially of the inset firebox type. On average I would say log fires put out less heat than a coal fire, but that's just my opinion.

The short answer is, noone can tell you whether it'll crack, you'll just have to decide if you want to take a chance.

Andy.