andrewpreece wrote:

"Martin" wrote in message
...

Hi Group,
I'm fitting a gas stove into the chimney opening in our front room.

The

spec of the stove states all surfaces should be at least 50mm from
non-combustible material. I would like to plaster the internal brick

walls

and paint them so as to have a smooth finish. So is plaster a
non-combustible material?

Thanks in advance,
Martin.



It is non-combustible. However, it's not terribly heat-proof. I doubt it
would last long
lining a chimney. I'm not sure if you mean you want to plaster inside the
chimney,
or plaster around the stove on the chimney breast. If it's the latter then I
think plaster
is OK.if you want to plaster inside the chimney the advice I have is that a
render with
lime in it is heat resistant, probably 1:3 hydrated lime:sand or 1:2:9
cement:lime:sand.
The first of those mixes is lime mortar and only achieves full strength
after 6 weeks
or so. The second mix will set more quickly as it contains some cement. I
defer to
anyone with more experience in the matter,


I totally agree with you. I have a similar finsih round my wood burner,
with masterboard for teh register plate, and its all fine.

I cautin that even that mortar (and teh bricks used with it) may degrade
in the rear of open fires where temps 1000C are possible.
Andy.