Hole in the wall fires

[biggeris better]

Hello everyone
I've come across a hole in the wall fire and wondering does any one know the materials to use on it as I've read gypsum plasters will crack with the heat.
I've greened the brick out for extra key I'm planning multi purpose mortar to block out and fix a galvanised stop bead for edge. I'll then skim.
Will the skim blow off with the heat being gypsum also will this tarmac multi mortar work ?

 

[Marshy]

Sand cement is fine and skim it after a day or two. Put bit of mesh in between your initial coat and filling out to the existing plaster

 

[Marshy]

And sbr in your mix

 

[CTPlastering]

Ive done a few just render inside without skim , just scratch and top coat , i worry about the skim failing with the heat , if it a log burner with a flue going in ?

 

[CTPlastering]

Ah s**t sorry its not the inside of the fire but the face egnore my last post

 

[biggeris better]

Cheers got them bits in cellar suppose the extra strength will help

 

[Marshy]

You had me wondering there Carl lol

 

[Marshy]

Cheers got them bits in cellar suppose the extra strength will help

The mesh is more to reduce the risk of movement once the fire gets hot but the hole in the wall fires are a mile away from wood / multi burners. I have one myself and plain rendered two coat but no mesh and sbr and only 2 small hairline cracks but to be fair our opening is too small for our fire so not all bad it's been in 2 year and we burn coal and wood and trust me it punches out some serious heat

 

[biggeris better]

What's the purpose for sbr I thought it was water proofing. I was also thinking of maybe a 2-3mm gap from the metal edge of the fire to the bead just to give it that movement

 

[Marshy]

Sbr reduces risk of shrinkage cracks in a big way but don't put too much in or you will feel like you are spreading chewing gum

 

[CTPlastering]

You had me wondering there Carl lol

A shud of looked at the photo and not presumed .... Lol

 

[Marshy]

The gap for the bead makes sense but to be honest as I said those fires are more something pretty to look at rather than a source of heating. I would bead almost touching so the customer doesnt whinge afterward

 

[biggeris better]

Thanks for the advice

 

[Marshy]

My pleasure mate stick some pics up of the job when your done? We love pics on here

 

[biggeris better]

I will do. it's going to be an ongoing job room by room so I can keep an eye on it over the next few weeks an see if the method copes with the heat.