Do you need grout behind fire??

[Gabby_Boating]

Has anyone tried not grouting the tiles behind the fire?! We're going to stick them on with some plumber flue silicone, but just wondering if there's a reason to use flexible grout or if I can just butt the tiles closely together and not use any?! 

 

Not having much luck googling! 

 

Thanks in advance :) 

[Tracy D'arth]

If there is no grout between them they may crack and craze with the heat expansion. I grout with white acrylic caulk, there is a bit of "give" in it.

[Captain Pegg]

That doesn’t sound like a good idea.
 

The purpose of grout in tiling - like mortar in brickwork - is to hold them apart as much as, if not more than, to stick them together.

 

The boat - and whatever the tiles are affixed to - will expand and contract and the tiles will be forced together and likely crack.

Edited September 16, 2023 by Captain Pegg

[blackrose]

Are you tiling onto Masterboard or some other cement- based fire proof board?

 

I don't think there's any reason to use grout if you don't want to. It might look a bit odd if you don't though. Try it and see 

 

Edit: we all posted at the same time. So apparently there are some reasons. I had assumed the gap between the tiles would be the same whether you used grout or not.

Edited September 16, 2023 by blackrose

[Captain Pegg]

1 hour ago, blackrose said:

Are you tiling onto Masterboard or some other cement- based fire proof board?

 

I don't think there's any reason to use grout if you don't want to. It might look a bit odd if you don't though. Try it and see 

 

Edit: we all posted at the same time. So apparently there are some reasons. I had assumed the gap between the tiles would be the same whether you used grout or not.

If there was a gap as you say it would probably be OK physically but it would look odd and I suspect the gap would be a dirt trap. The grout presumably also helps to protect whatever is behind it. The OP suggested butting the tiles together which is definitely a bad idea.

[jonathanA]

Sticking them on with silicon sounds like bad idea to me.  Mine where like thst and all fell off or came loose. Redid it with a decent tile adhesive not the premixed white stuff.

 

Don't really understand why you wouldn't grout. Although i wouldn't use white grout for the fireplace.

[Chewbacka]

2 hours ago, Captain Pegg said:

If there was a gap as you say it would probably be OK physically but it would look odd and I suspect the gap would be a dirt trap. The grout presumably also helps to protect whatever is behind it. The OP suggested butting the tiles together which is definitely a bad idea.

Agree about the dust trap - If you don’t use grout it won’t be long before you have a soot and general dust grout that needs cleaning out with a tiny brush.  Just use high temp adhesive & grout onto a silicate board.  

[Onewheeler]

I've had an intention (for a long time) to put very large tiles (75 cm or more) over the fireboard, held in place with wooden beading at the edge and probably spacers with flexible mastic in-between the horizontal joints.

[Sea Dog]

My large (600 X 300) tiles are stuck on with Vitcas 300c silicone and "grouted" with normal white silicone, which is good to about 200c. This because my original tiles used tile cement and were coming loose. If I did it again, I'd probably use Envitograf (1200c) silicone I did my stove top collar with. Not because the tiles get hot (they don't with a metal heat shield on the back of my stove and a decent air gap) but because it's so much nicer to use and easier to get a great finish that the horribly sticky, hard to work Vitcas stuff.

[ditchcrawler]

7 hours ago, blackrose said:

 Edit: we all posted at the same time. So apparently there are some reasons. I had assumed the gap between the tiles would be the same whether you used grout or not.

If there was surly it would be a pain to keep clean

[Gabby_Boating]

Thanks everyone!! Noted to use grout to fill the holes - thank you. I think we'll go for a flexible grout but I'll look into that envitograf! Thanks 👍

[LadyG]

On 16/09/2023 at 13:48, Onewheeler said:

I've had an intention (for a long time) to put very large tiles (75 cm or more) over the fireboard, held in place with wooden beading at the edge and probably spacers with flexible mastic in-between the horizontal joints.

I've got that, I decided the previous owner picked up eight tiles in the discount box at the door of the store. They are floor tiles. Might look ok if it's a modern industrial , expensive tile, but not a cheapo floor tile look.

Edited September 17, 2023 by LadyG

[jonathanA]

Big tiles are great for big flat spaces like floors.... not so good for odd shaped not quite square or slightly curved boat surfaces....  if your stove is on the usual  bow to one side corner then you might have a reasonably vertical bow bulkhead and and a definitely not vertical/flat  curving in bow side...   makes matching up grout lines very hard..  if you can faff about with your backing cement/fire board and get those nice and flat then maybe....

[Chewbacka]

The bigger the tile the greater the stress when the tile expands.  A small tile doesn’t have much ‘expansion’ growth at the edges, where as a big tile does so is more prone to coming loose.