Join sandstone and plastered wall near woodburning stove

[JKScotland]

Hi all,

I've got a question about what material to use to point/fill/seal a small gap between our sandstone fireplace, and the plastered wall (cement board) that almost abuts the sandstone.

It will be a visible join between the smooth plastered wall and the rough exposed sandstone so it needs to look good, needs to handle the heat (probably within 30 cm of the side of the stove) and may need some flex. The wall is a couple of cm proud of the stone.

Someone has told me that mortar will just crack. I like the look of the burnt-sand-mastic (old fashioned building mastic) that was used on our refurbed sash windows, but don't know if it would stand up to the heat. Heat resistant sealant might work, but don't think it will look natural. Mortar or stone look would be nice. Pic attached... suggestions welcome!

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• JKScotland
• 16 May 2014
• 1

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[geraldthehamster]

I haven't done this, but would suggest that a lime mortar should have the flexibility you want.

Cheers
Richard

 

[JKScotland]

Thanks for the input Richard. I've had similar feedback from a stove expert nearby, with the only caveat that adhesion to the board might be the biggest challenge.

We'll see how it goes -- I recently bought a bag of premixed lime mortar with plenty left. Sounds like a good place to start.

 

[ree]

FWIW: Fire Cement comes in various colors, including a stark contrasting black. But neutral F/cement dries like mortar.

Why not wait until after the stoves been in operation, and see how hot it possibly might get before doing anything?

 

[JKScotland]

Hi, ree... fire cement might be an option - I'd like to see what it looks like in person before trying it. And leaving it until the fire's been operating is probably a good idea though there is pressure to get this room "finished"!