Wood burning stove plastering/ rendering issue

[alex77]

Guys,

I am after some advice.

I am fitting a wood burning stove into an existing recess in a chimney. Flue draw is ok.

I have removed the plaster, and cleared out the opening such that I now have a nice square hole with a 9” concrete lintel. I want to avoid using a fire surround as I would like a more modern, minimalist look.

My question is, what do I finish the inside of the hole with?
Sand/lime/cement render??
If so how do I connect this into the plaster on the front of the chimney breast. If I use a steel edging bead will this lead to cracking of the plaster or render as it expands, especially in the area directly over the stove? There is a 250mm gap between the stove and the lintel.

Are there any better materials or more cunning details?

Also, any idea what I should paint with in this area?

 

[RigidRaider]

We did exactly the same thing and now we have a craze of cracks all over the plaster at the back of the recess and about a foot all round the edge. TBH it doesn't look too bad from the other side of the room, it's only visible from close up. Not sure how to fix this but:

Ask your plasterer for a plaster, which can resist the intense heat from the stove. What you need is something with a low coefficient of expansion.

Don't do what we did and only repair the plaster for a foot or so around the hole. It will crack at the interface of old/new. We wish we had removed all plaster for several feet around then refinished most of the wall so as to spread out the stresses from expansion and contraction.

BTW we later decided we wanted a wood lintel to finish the bare hole off. For ease of decorating and to avoid drying/expansion cracks around the edges I bought a length of very old pitch pine from a salvage company, fitted mirror plates recessed into the back and hung it from two SS screws above the fireplace. It looks like a permanent lintel but can be lifted off for painting.

Another point - we have more cracks appearing at the top of an outside wall in the room where the thermal expansion is probably at its greatest. A huge chunk of plaster is about to drop out. This is one of the consequences of the intense heat generated by our multifuel burner on full vent!