Stove blowing plaster off wall

[geraldthehamster]

Can anyone suggest a suitable board material to fix tiles, to, and attach to a wall behind a wood-burning stove?

We had our stove installed earlier this year. It stands in a corner, on a hearth of 9 inch pammets. The wall behind was re-skimmed not many weeks before the stove was installed. Although the stove is a good 6 inches from the wall, I noticed last night that the plaster is cracking, and about to blow off the wall.

I want to avoid removing the stove, so there isn't access to render the wall. I thought of attaching tiles to a board, sliding the board behind the stove (there is clear access from one side), and sticking to the wall with tile adhesive, to cover the damaged area. I imagine it would be advantageous to fix the tiles to the board with a cementitious adhesive. Can anyone suggest a suitable material for the board, or alternatively something I could use without fixing tiles to it? I don't want it to look too modern, otherwise I'd consider a sheet of zinc or aluminium.

The plaster is only cracking up to the height of the stove itself, and not behind the exposed flue pipe. So the solution only has to be the height of the stove.

Cheers Richard

[Andrew Gabriel]

I've played a blowlamp on plaster whilst soldering pipework, and nothing happens to the plaster other than discolouration (didn't cook it up to red hot though). Not sure what happened in your case. If it dried before it set, that might explain it, but it sets in a few hours (assuming gypsom based plaster).

[js.b1]

Any cement board. B&Q

do a Cement Particle Board of 1200x600mm for =A314.78,

6mm thick, quite adequate.

Glass masterboard is better, but tends to be bigger & gets expensive fast.

Such boards are heavy, you can drill & saw but treat with care as they can fracture. They are better than "that rubbish known as plasterboard" :-)

Moisture behind causing localised cracking. If the wall is solid or somewhat damp (eg, from water coming down a chimney) it can blow. If the wall is plaster skim over sand-cement render which was merely shown the cement bag label then it can be quite "friable" and separate relatively easily". A skim without a good PVA bond underneath can crack when heated because the bond is not so good.

Mapei Keraflex will tolerate movement re tiles to cement board. You could use the cement board on its own, it has a better-than-MDF look to it and is Class-0 fire rated of itself.

Is there a broken silica fire brick within the stove, ie, you are getting a localised hot spot. They get pretty hot anyway.

[geraldthehamster]

It's pretty well known, I think, that gypsum plaster isn't up to the job of withstanding high temperatures for any length of time. That's the reason we had the stove so far from the wall, but it wasn't far enough. It's the reason that cement render or lime are recommended for fireplaces with stoves in.

Cheers Richard

[geraldthehamster]

Thanks, cement board is the way to go, then. I don't think anything is broken. The damage is pretty uniform behind the back of the stove.

Cheers Richard