I'm planning to dry line the walls of a room with 2" battens, 2"
polystyrene between them and 1/2" plasterboard on top. The
plasterboard will then be painted (no plaster or wallpaper). I also
want to install a woodburner in the room (obviously I will have to
allow for a hole in the wall for the flue to go into the chimney,
which will be lined with a flexible flue liner).
What I need to know is: how far should the woodburner be from the
walls in order to stop it damaging them. Although I know that
plasterboard is fire retardant, I assume you can't have a heat source
too close to them permanently. Is the 6" of hearth enough, or do I
You need *a lot* more. Wood burners radiate a huge amount of heat when
they get going. I don't think you want any plasterboard within 2-3 feet
of the wood burner.
In reality, this means that you need to surround it with brick/stonework.
Can I assume that any other commonly used insulation material IS safe?
And if I use multiboard, will this be sufficient to protect the wooden
battens behind it?
I do have the option of leaving the brick walls bare in this corner,
but they don't look very nice and I'd prefer to have them insulated
More or less. All the others char and fume but don't really burn.
Not sure about IMM's famous celullose stuff tho. That probably burns
better than a baby soaked in Napalm.
Its all a matter of how hot/how near. You can heat pslaterbaord up to
red heat. The cvardboard burns, teh gypsum goes crimbly and falls to
pieces. It is quite a good insulator.
Mutltiboard you can do the same to. It holds together better if you do.
Neither of them will protect woodwork directly behind if you play a
blowlamp over the top for long enough.
OTOH if its just a couple of hundred C, i'd say yes.
ell, get teh stove in, light it, and nail a small piece of batten to the
hottest part of teh wall, and see if it chars. Then nail a bit of
plasterboard ovet the top and see what that does. If its obvious that
ist getting too hot, use multiboard. If necessary use sapcer strips
betwen the main board and the batten to increase insulation.
If it definitely IS too hot and I have to use multiboard, how should I
fix it? If I use metal screws or nails, won't these conduct the heat
right into the battens?
Also, what to do about joints? Where it meets the normal plasterboard
will necessarily be at a safe distance but there will almost certainly
be a corner join between 2 multiboards which is not at a safe
distance, so presumably joint tape is out. And if I don't seal it
somehow that could be an easy way for heat to get through and melt the
DPM. Aaarrghh! it's all so complicated...
Or am I just being paranoid?
I think you are being too fussy.
The point of using masterboard etc. is to add a little more fire barrier
and insulation. If the wall is getting that hot, then nothing short of
cast iron will be good enough anyway.
All you are really concerned about is not having e.g. bare painted wood
near the fire. That will bubble smoke and char. Stivking sud behind
plasterboar will take a fair bit of heat, up to the point where the
board starts to crumble. The wood should be fine up to thatpoint.
Masterboard etc is not so much something that does any better than
plasterboard in normal terms, but simething that, in the event of a
serious fire, or total overheatuing of your fire, will protect the wood
longer, becaus it maintains physical inegrity at higher temps aywy.
But by the time you get that hot, any painted plasterwork is going to be
To summarise. If it gets that hot round teh stove, a paint fih is not
going to survive, in all probability: Use a metal plate screwed down or
If it doesn't get that hot, plasterboard will outlast the paint its
covered with, but mulitibard will outlast that in a fire.
I'm doing the same except 3" battens with 2" kingspan i.e. 1" gap
between plasterboard and insulation. Re condensation - seal gaps in
insulation with tape or foam filler and use plasterboard with foil
vapour barrier in back. The 1" gap is extra insulation and also sound
The woodburner will be about 6 to 9" from the wall and I intend to put
that asbestos substitute board whose name I've forgotten, behind the
stove and flue pipe. Or, if I can afford it - steel plates with black
stove finish - to absorb heat and radiate it back into the room. This
will even out heat transmission to the wall itself and reduce hot
I've already fitted the stove, a 'Firebug' from
http://www.dowlingstoves.com/ and we are very pleased with it. It also
burns sawdust by virtue of it's pyramid shape - i.e. the sawdust heap
in the stove settles slightly making an air gap all round and
combustion then takes place over the surface. i.e. 2 or 3 shovelfulls
at a time.
I know. My original post was specifically asking about how close you
can safely put a woodburner to plasterboard so I didn't mention every
detail of the dry lining.
However, this leads on to another point that I'm not sure about: I've
read that the DPM can be attached with "staples". What kind of
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