slate mosaic tiles with less than 1mm gap - can't grout

[jofusmofus]

Hi all,
I've not done much tilling so apologise if this is a silly question and please answer in layman's terms!
I've got some Uncalibrated Linear slate mosaic tiles from Topps to lay in a bath shower area. Now I'm looking at them I've realised the joints between the pre glued together tiles are tiny. There's no way I could grout them. I mentioned this to the guy in topps and he said I need a trowel that will ensure a solid bed of waterproof adhesive behind the tiles and then they'll be waterproof in a shower area. And I don't grout them. What are your thoughts and what kind of trowel would you use?

Thanks in advance

 

[Gazzer]

Has the area been tanked ? Its not something i would reccomend in a shower anyway.

 

[jofusmofus]

It's not been tanked....it's hardibacker board behind which has been primed. The tilling manufacturere says it should be OK for shower areas.

 

[White Room]

Primed with what

 

[jofusmofus]

It's called BAL bond SBR
I've been going on the advice of Topps but now not sure about these grout lines!

 

[White Room]

Personally I would have tanked it, the addy won't waterproof it but you can get grout which will do 1mm

 

[easyt]

I wonder how slippy sealed slate will be in a shower.

 

[Gazzer]

I wonder how slippy sealed slate will be in a shower.

I presume they are on the wall !

 

[White Room]

Thats what I thought

 

[DJS]

I've seen these tiles before, used them to make a bath panel. I would definately use tanking membrane or gum, if you really want to go for it.

I'd say go back to the tile manufacturers and ask them to be more specific about the type of adhesive. My understanding, from what you describe, is that you would need an epoxy based adhesive. I think black or dark grey Mapei Kerapoxy may also be suitable for these tiles, as I seem to recall the manufacturer instructions stating it can also be used as an adhesive, I'd use a 2 or 3mm mosaic trowel. You'll have to check this for yourself though, as I am fairly new to this.

With that all said....I have to agree with Sir Ramic, I wouldn't want to use them in a shower area!

It just seems to risky not having the small gaps filled. Even if you tank and use a truely waterproof adhesive, there's still gonna be soapscum build up and mould eventually, which will be difficult to remove from inside the gaps.