Tiling onto calcium silicate boatd

[pollip]

I need to tile onto 25mm calcium silicate board for the hearth and surround. I’ve done abit of digging and some say heat resistant silicon some say standard flexible tile adhesive, my worry with the tile adhesive is it’s only heat resistant upto 90degrees and I assume the tiles will get a fair bit hotter than that... any recommendations ??, I’ll also need some form of grout so reccomendations on that would be great aswell. Ta

[blackrose]

My vote goes for heat resistant silicone. Some will say ordinary silicone is just as good, but they don't know your stove installation. 

 

If you use tile adhesive I think you might have to seal the absorbent board first with PVA.

Edited April 12, 2021 by blackrose

[pollip]

29 minutes ago, blackrose said:

My vote goes for heat resistant silicone. Some will say ordinary silicone is just as good, but they don't know your stove installation. 

 

If you use tile adhesive I think you might have to seal the absorbent board first with PVA.

I was just about to say would I need to seal it, would I need to seal it with the silicon ??. The boards are really darn chalky/ powdery 

[Tony Brooks]

I sealed mine with dilute PVA and then used silicon and ordinary tinted grout

[blackrose]

Yes you'd be wise to seal a powdery board first whatever you use.

 

Grout with a flexible grout afterwards.

[nbfiresprite]

Used Wilko's own Tile adhesive and grout.

[Sir Nibble]

I think you are over estimating how hot it's going to get. Shiny ceramic tiles will reflect back most of the radiated heat.

[blackrose]

20 minutes ago, Sir Nibble said:

I think you are over estimating how hot it's going to get. Shiny ceramic tiles will reflect back most of the radiated heat.

 

In that case why bother with heat resistant board in the first place?

 

Tiles can get quite hot in my experience and conduct that heat right through them. Quite a few boat fires have started from unprotected charred wood behind tiles.

Edited April 12, 2021 by blackrose

[Sir Nibble]

9 hours ago, blackrose said:

 

In that case why bother with heat resistant board in the first place?

 

Tiles can get quite hot in my experience and conduct that heat right through them. Quite a few boat fires have started from unprotected charred wood behind tiles.

Rather depends on how close the stove is. I could run my squirrel hot as hell and the tiles were never as warm as the radiator. In my case the heat resistant board was there for the sole reason that BSS required it.