Woodburner - plastering over chimney breast

[justlearner]

I have a 1930's house, where the previous owners have removed all the plaster from the chimney breast, then painted the brick with silk emulsion (?). They have then installed a woodburner, which is half in and half out of the fireplace.
I'd like to re-plaster the chimney breast, but my sources tell me that you can't get a good key onto painted brick, and that the considerable heat rising from the woodburner will damage skim coat/plasterboard.
All suggestions gratefully received: painted brickwork in a 1930's house looks odd: it's not a stonebuilt cottage.

 

[Richard C]

I’ve not done anything quiet like this before & it’s why I didn’t initially respond but as you’ve got no other takers then this is what I think;

I would be unhappy using D&D plaster board in such a location. Silk emulsion can be a pig; what I do on ordinary walls (i.e. not over a wood burner!) is to thoroughly score the paint right back to the plaster (or in your case brickwork) using an old scraper or trowel; use criss-cross diagonal slashes around 30mm apart & then go over the whole area with a very stiff wire brush. I would normally then use a PVA bonding strength coat & let dry over at least 24 hours, then PVA & skim; I’ve never used it but in your case I would suggest something like this instead:

http://www.british-gypsum.com/produ...le_plaster_bonding_agents/thistlebond-it.aspx

I would then apply a Bonding plaster base coat & then skim; these plasters can withstand temperatures of a normal chimney breast (up to 49 degrees) but you say your fire is half in half out so the temperature may be higher in the immediate adjacent area. I would suggest you measure the temperature of the brickwork around the fire with a thermometer before going ahead.

 

[PerryOne]

Use an angle grinder with a diamond tipped cup and grind the paint off.
Then wet plaster.

 

[justlearner]

thanks guys.