Help!: 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

[Sir Ramic]

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.

[whitebeam]

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!

[whitebeam]

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.

[Sir Ramic]

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

I presume they are on the wall !

[whitebeam]

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.

[jofusmofus]

Thanks for all the help guys.
Yes they're planned to go on the walls. It's just a strip of them vertically behind the over bath shower really.
I appreciate all your comments and help. It's Topps Tiles Trade rapid set flexible adhesive I've been given....any ideas on it's waterproofing ability?!
I'm going to get in touch with the manufacturer of the actual tiles (once I work out who that actually is) and see what their recommendations are.
Does anyone know of any tiles similar to this slate mosaic style which maybe do have joints which can be grouted?! There's a link below of the tiles for an idea of what we want I just can't find any similar anywhere really in case my plan with these falls through.
NSM Uncalibrated Slate Linear Mosaic | Topps Tiles

And if it does turn out to be a bad idea....does any one want to buy some tiles!? 53 of them!

Cheers

[easyt]

If you do change your mind Topps Tiles have a 45 day return policy.

[DJS]

They are very similar tiles as I fitted before, but the one's I had were all same length - normal brickbond.

The adhesive TOPPS sold you is cement based, meaning it will still allow water to penetrate but not damage it.

As already said, you could tank the walls, to stop the water penetrating further. However, I still beleive you would suffer from mould long term, due to soapscum buildup in the small gaps (even using a premium sealer).

If your still wanting to reasearch it, I would check suitability with tile manufacturer for use in a shower, and what they would recommend as an adhesive - epoxy based or cement & tanking.

I'm feeling for ya, because I thought the tiles look very nice too. I would have them in my house - I wouldn't risk it in the shower though!!

Maybe use a more regular calibrated slate mosaic that has 2mm grout lines, if that goes with the rest of your tiling scheme?

Good Luck, and let us know if you need any more advice.

[Dave Ramsden]

Is this the tile in question?

http://www.flickr.com/photos/4688210...7625071438516/

I was talking about this the other day, You can get some that are sealed behind so they dont need grouting but I wouldnt reccomend them in a wet area. The ones pictures arent grouted

[jofusmofus]

Again, thank you all for the sound advice. I have been in touch with the manufacturer of the tiles and they tell me they are fine to use in shower areas but I need to use Homelux matting behind them. And make sure I seal them with several coats when they're fixed.
So I think I'll take the advice of the manufacturer and go for it but has anyone any advice for using homelux? Is it layed ontop of a layer of cement adhesive? Any other advice when using it? And does anyone know where's cheapest to buy it? 50quid for a 5 metre roll is about the cheapest I've found so far.

Thanks again guys, I'll upload some pics when I've finished....probably in about a years time at this rate!

[Dave Ramsden]

If your referring to a moisture membrane the n yes it is fixed down with a flexible adhesive suitable for wet areas. There is plenty of advice on this on the forums if you use the search function

[jay]

the tile in question is called stack rock if laid above 3 metres in height you need to use epoxy adh under that you need a c2 adh i wouldnt recomend using in a shower because of moisture getting behind rock due to no grout and that will cause mould and all sorts of probs normally used as feature wall if you do lay in shower area use a good membraine hope this helps

[Fraser]

havent read every reply, but mapei do keracolour ff, a fine grout that will do a 1mm joint

[Phil Hobson]

Hi, not the same slate, but tight joints. I grouted this in Norcross grey, once sealed it was fine

[DJS]

Thanks for letting us know what the manufacturers said. So they do rely on a WP tanking membrane for a wet area. The homelux matting is tanking/waterproof membrane that also just happens to be supplied by TOPPS, so I think you could follow any of the previous advice about tanking products. I think as the manufacturer sell tiles to topps, they are just referring your back to them for another sale.

As I used these tiles before, I think grouting might detract from the overall sleek look they give, as they are uncalibrated and almost butted up to each other. I recall the sharp corners will pretty much rip your sponge to bits anyway, so grouting would be very difficult to clean up.

That said I still agree with Jay about the possibility of mould so as you decided to go ahead with it, then be prepared and try to keep them well maintained. If you do get problems in the future, my advice would be to treat it chemically, and then try some fine grout. Otherwise you'll be looking at removing and replacing them. And as they are slate tiles, I would give them at least 1 coat of sealer before you fix them too.

Good Luck with it, a pic is always nice no matter how long it takes

[Shoggers]

I have the exact same predicament
Just laid some nice 40x40 slate tiles on the floor in a long thin bathroom. I wanted to use these tiles on the end feature wall where the shower is located, but having read all these comments I'm not sure now.
I have seen similar looking ones but porcelain/ceramic and they dont quite have the quality finish im looking for.
Please let us all know what you decide with this and I think I will hold off buying them for a while.