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

"Chris Styles"  wrote in message 
news:dgorur$ob5$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...

> 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.