Natural slate tiles in fireplace - which adhesive?

I've taken out an old 1930's fireplace and now want to build a simple hearth to stand a multifuel freestanding stove. I'm planning to use 30 x 30cm natural stale tiles with grey grout, but what is the best adhesive to lay the tiles onto the exisitng concrete base?

Could I use a simple sand mortar mix or do I need special adhesive? Don't fancy using white adhesive as I'm worried about staining the slate.

What would be your suggestions?

You need a powdered cement adhesive & grout, very unlikely anything less will withstand the heat. You won’t go far wrong with this stuff;
http://www.bal-adhesives.co.uk/products

You need to provide spacing between the tiles to allow for expansion or the tiles may crack but my advice would be don’t space them too wide & possibly don’t use grout between the tiles at all. Some months ago I installed a multi-fuel stove & used a manufactured polished granite hearth suitable for solid fuel (around £170) but constructed my own surround from 600 x 300 x 12mm polished granite tiles; I didn’t use grout but spaced the tiles at ½ mm & ran some black silicone down inside the gaps.

Don’t use ordinary Gypsum plaster for repairs or as a base to tile onto around the stove either. It will only withstand a temperature of around 50 degrees & will crack/blow if exposed to temperatures much higher. You need to use a sand/cement/lime render base &/or a special heat proof render/plaster within 300mm at the sides & at least 500mm above.

I have an inset cassette stove & measured the wall/hearth temperatures immediately around the stove at 40 degrees at the sides & 70 degrees in the immediate hearth area & in the wall above the stove itself. Mines been operating almost daily for around 6 weeks now without any sign of problems.

Fjt. About a year ago I did exactly what you are proposing.


I did it in the same way as Richard advises although I used a standard screed for the hearth, standard 4mm gaps between the slate and grouted with mapei black grout. I used Bal rapid set as the adhesive.

Never had any problems with the fireplace and have it burning at weekends.

toptec said:

standard 4mm gaps between the slate and grouted with mapei black grout. I used Bal rapid set as the adhesive.

Click to expand...

I used Rapidset adhesive but, as I’d never done any high temperature tiling before, was concerned that the grout might crack so I kept the spacing to a minimum to cater for expansion & used black silicone; interesting to hear you’ve not had any problems with the grout.

You don't need to worry about heat if you are installing a free-standing stove as there is no direct contact between the hot part of the stove and the surface of the tiles. You can easily put your hands near to the stove without burning yourself so it's hardly going to damage natural slate and/or grout. So don't spend extra money on heat-resistant cements, normal adhesive and grout will suffice.

hallamj said:

You don't need to worry about heat if you are installing a free-standing stove as there is no direct contact between the hot part of the stove and the surface of the tiles. You can easily put your hands near to the stove without burning yourself so it's hardly going to damage natural slate and/or grout. So don't spend extra money on heat-resistant cements, normal adhesive and grout will suffice.

Click to expand...

Why have you posted a thread that is 2 years old As I stated back then, a Rapidset powder cement adhesive, there is nothing special about it & it will withstand 150 degrees C which is more than enough.

Richard C said:

toptec said:

standard 4mm gaps between the slate and grouted with mapei black grout. I used Bal rapid set as the adhesive.

Click to expand...

I used Rapidset adhesive but, as I’d never done any high temperature tiling before, was concerned that the grout might crack so I kept the spacing to a minimum to cater for expansion & used black silicone; interesting to hear you’ve not had any problems with the grout.

Click to expand...

silicone with high heat..... dickie boy..... tut tut..

Oh go away you numpty, there is nothing wrong with using silicone in high heat applications; it will withstand temperatures up to 200 degrees C which no hearth or surround will ever reach. Rapidset tile adhesive will only take 150 degrees & that works fine.

Do you ever check anything before you post the disruptive garbage you come out with.

geraint said:

Richard C said:

toptec said:

standard 4mm gaps between the slate and grouted with mapei black grout. I used Bal rapid set as the adhesive.

Click to expand...

I used Rapidset adhesive but, as I’d never done any high temperature tiling before, was concerned that the grout might crack so I kept the spacing to a minimum to cater for expansion & used black silicone; interesting to hear you’ve not had any problems with the grout.

Click to expand...

silicone with high heat..... dickie boy..... tut tut..

Click to expand...

You can use silicone to stick engine gaskets in place, and how hot does an engine get?
Answer VERY!!