Limestone Tiles - Laying Tips (am I Mad?)

[Ajax123]

It's BS5385-4 ... And it doesn't say a membrane must be used but it states it helps eliminate stresses associated with green screeds etc that are not fully cured .

I'm sure there is a TTA technical document being prepared about the use of membranes , as of yet there is no BS covering them.

That's it Dave. You are quite right it doesn't specify how uncoupling should be achieved but it must be acknowledged that a simple membrane is probably the easiest modern method. We used to use sand in the old days...

 

[Dave]

That's it Dave. You are quite right it doesn't specify how uncoupling should be achieved but it must be acknowledged that a simple membrane is probably the easiest modern method. We used to use sand in the old days...

It's coming Alan , it's been in the pipeline of BS updates for a while now... 🙂

Did you attend the seminar by the TTA on tiling to calcium sulphate screeds by Colin Stanyard.

 

[Ajax123]

It's coming Alan , it's been in the pipeline of BS updates for a while now... 🙂

Did you attend the seminar by the TTA on tiling to calcium sulphate screeds by Colin Stanyard.

No but i doubt I missed very much.

 

[Dave]

No but i doubt I missed very much.

I would like to have heard it .. A seminar by a company without a gypsum adhesive yet.

 

[Dan]

It's BS5385-4 ... And it doesn't say a membrane must be used but it states it helps eliminate stresses associated with green screeds etc that are not fully cured .

I'm sure there is a TTA technical document being prepared about the use of membranes , as of yet there is no BS covering them.

That's it Dave. You are quite right it doesn't specify how uncoupling should be achieved but it must be acknowledged that a simple membrane is probably the easiest modern method. We used to use sand in the old days...

I was assuming to be fair. But only based on the fact that such a membrane has only been around a decade and the regs don't get updated as fast as the industry changes.

And to be honest, adhesive manufacturers didn't have their own until recently so the regs would have been recommended one or two brands only. And I couldn't see that washing.

Adhesive firms obviously make their materials to cope with such stresses. End of.

Nothing actually requires such a membrane. Nothing at all.

When you use one; you're avoiding redeveloping a floor. That's what they're really for I guess. A new floor shouldn't need one all.

 

[Dave]

I was assuming to be fair. But only based on the fact that such a membrane has only been around a decade and the regs don't get updated as fast as the industry changes.

And to be honest, adhesive manufacturers didn't have their own until recently so the regs would have been recommended one or two brands only. And I couldn't see that washing.

Adhesive firms obviously make their materials to cope with such stresses. End of.

Nothing actually requires such a membrane. Nothing at all.

When you use one; you're avoiding redeveloping a floor. That's what they're really for I guess. A new floor shouldn't need one all.

That is so wrong in many ways .

A cement based screed cures over it's first 6 months cycle and over this period it may well crack , so do you tile it and cross your fingers
or uncouple and never look back.
No two floors behave in the same way , is it worth the risk , ???? Only you decide lol.

 

[TCS]

Thanks for all the replies & advice everyone!

Slightly confused on a couple of things.

When you say use a "solid bed"...is that applied with a flat trowel or a notched trowel? I had assumed I was using the latter.

Back skimming the tile seems to make sense, I assume that is a skim of adhesive, applied with a flat trowel, about 1mm thick, covering the whole back of the tile? - I picked this up from another thread on here.

Is the movement mat really necessary then in my situation? Thanks for the pointer on the tilemaster mat (comes in around £130 for 20m2). I'd need 4 rolls, so an outlay of £520! And if I don't need it, that's quite a considerable saving! BUT, on the otherhand, not using it could be a very expensive mistake! Hmm...

Sorry for the daft questions.

Thanks again!

 

[TCS]

Also, thanks for the tip on measuring or sorting the tiles in terms of thicknesses. I think they are very similar thicknesses, but I have got a measuring device to help me go through them.

On the back of the tiles, they have grooves in them, so I assume they have been sawn cut (I will post a photo later this evening).

 

[TCS]

Ignore the fact that they are broken - they arrived like that and have since been replaced with unbroken ones...

Anyway, this is what the back of the tiles look like:

 

[TCS]

Ok, a quick update and a couple of little questions!

Well, I spoke to a chap at Tile Town (who are literally 10 mins down the road for us), who was very helpful. He spoke to the adhesive guys, explaining what spec UFH screed I had, how long it had been down and the type of tile that I was laying, and he confirmed that no mat was required, so we took the gamble and laid it without.

Thanks to the vote of confidence and advice on here...so far, we've laid about 18m2 out of 25m2 to the first area. We've used a 12mm trowel and back skimmed the tiles as advised. The larger tiles seem to be easier to get right than the smaller ones, which surprised me somewhat. So yes, progressing steadily, but getting there - famous last words!

Anyway, my questions are regarding movement joints and grouts.

Movement joints

It seems to be a minefield out there and no one seems to stock the size that we need. We need a joint with a depth of 25mm. There seems to be a choice of stainless steel or aluminium? Medium duty or heavy duty? I've narrowed it down to:

(which is 25mm deep, but comes in grey only):

AD Fix Movement Joints 25mm [ADF25] - 30.00 : Floor & Wall Solutions, Carpet, Vinyl, Tile Trim and edge protection profiles covered!

or this (which is suitable for 22.5mm deep tile, but also comes in black or beige):

Optimax Aluminium Movement Joint - Heavy Duty 22.5 mm [MSA225] - 16.59 : Floor & Wall Solutions, Carpet, Vinyl, Tile Trim and edge protection profiles covered!

1. Would it be wise to go with beige to match my grout (see next question) or grey to match the tiles?
   
   
2. Does the movement joint trim sit on the subbase or is it sat on a smeer of adhesive to each side of the gap?

GROUT

1. The width of my joints are generally around 15-17mm, but it some areas, where the stone is naturally cut, the gap is more like 25-30mm and I can't seem to find a grout manufacturer that does grout suitable for gaps over 20mm. Can I get away with the max. 20mm grout or is there specialist stuff out there?
   
   
2. And finally the colour. The options seem to be a cream (Limestone) or grey. We like the idea of the limestone colour, but worry that it will discolour and look dirty. Is this usually the case?

Sorry for all the questions again, but we are steadily getting there and google don;t seem to be returning and decent answers.

Will hopefully post some photos of the area once completed, if anyone is interested?

Thanks again.