Limestone Tiles - Laying Tips (am I Mad?)

[TCS]

I've just bought 85m2 of these Limestone Tiles

The sub-base consists of a wet UFH system, covered by Keracem Eco screed. Commisioned and has been running since Nov 2014, so nice and dry.

I've laid tiles before, but nothing remotely on this scale, nor any tiles so large. The pattern is random lengths (900/600/400 @ 560mm wide and 20mm thick).

There is 75m2 overall, but split into different areas, with movement joints (and doors) splitting the areas up. (i.e. kitchen area is the first area to undertake which is just 25m2 in total).

From my initial research, I've discovered the following:

1 - I need to use white flexible adhesive. It seems to make sense that I use Kerakoll Tenaflex, as this was recommended by both the tile supplier (Ca Pietra) and screeders (Keracem).
2 - Trowel size required, I'm thinking 12 or 15mm?
3 - Install a movement matt between the screed and the tile - Ditra or Dural - the latter seems to be somewhat cheaper than the former - are there any pro's/con's from either?
4 - Movement joints in the screed must mirror in the floor tiles
5 - We'd like wide grout joints (like the photo above) - are there "spaces" out there that can achieve a wide joint or do I just do it all by chalk line?

None of my walls are parallel or square, but that is nothing new.

Can anyone give me any tips? Or is it a "get a Pro" in only. I'm far from new to DIY, so would like to give it a go myself, but can understand why people would advise otherwise.

Any advice/help would be much appreciated - I'm hoping to get started in the next week or two.

I'm also based in Derbyshire/Nottinghamshire if anyone in the area would like to quote for the job (pm me etc).

Cheers!

 

[Dan]

You've got some balls.

Go for it.

Sounds like you've done your research there.

Could you not have had a go of a 8.5m2 area first haha

 

[Dan]

You can get spacers that are quite big but realistically as long as something is a constant you can use anything. Window packers that window fitters use are a god send. Easy to pull back out after too if you leave them sticking up right so you pull them out as you go along.

 

[Dave]

That's Bastille limestone and a very hard tile..... You space them by eye as the edges are uneven .

Solid bedding as per the norm but make sure you work clean and seal before grouting once clean and dry , the brushed surface can grab grout ...

 

[widler]

Same stuff I think, jasmine grout

As Dave said, solid bed plus back butter the tile.
lay ditra or tile master have one which is very good, easy to cut and only .85 of a mm thick .
Personally I'd use standard set white if your a novice, cut in as you go along,don't leave until last, as they will be different size widths/lengths .
Sort thick to thin, as again they will vary , use thickest 1st.
A must is sealing before grouting, even then , with them being rough tiles I have a lad behind me sponging off excess around the joint , not over the joint, just gently around .

 

[Dan]

That's a good tip I've never seen! Sort thick to thin and use thick first. Totally makes sense. The other way around could cause some headaches and probably a nice sloped floor!

 

[Dave]

A good grade Bastille should be +\- 2mm , that won't be noticeable on this type of tile as the joints will range from 5mm edges to 20mm etc on the corners.. If the backs are sawn finish then deffo double bed if flat finish then back skimming as Craig says is a must anyway...

 

[Dan]

Ahh okay so on an average bed of adhesive you're not going to spot the thickness differences.

 

[Dave]

Ahh okay so on an average bed of adhesive you're not going to spot the thickness differences.

Nope , these tiles are slightly uneven anyway on the face ... Laid crates of it ... Really nice and very hard wearing.

The 900 x 600 are heavy beasts lol...

 

[Dave]

Same stuff I think, jasmine grout View attachment 73738 As Dave said, solid bed plus back butter the tile.
lay ditra or tile master have one which is very good, easy to cut and only .85 of a mm thick .
Personally I'd use standard set white if your a novice, cut in as you go along,don't leave until last, as they will be different size widths/lengths .
Sort thick to thin, as again they will vary , use thickest 1st.
A must is sealing before grouting, even then , with them being rough tiles I have a lad behind me sponging off excess around the joint , not over the joint, just gently around .

Yep , that's Bastille...

 

[Dan]

Need one of those dolly's from Aldi that ray managed to find!

 

[Dave]

Need one of those dolly's from Aldi that ray managed to find!

I've had 2 and they both fell apart lol lol..

 

[On one]

I know the floor is a heated screed and the tiles are natural stone,but would an uncoupling membrane be absolutely necessary......considering that the stone is Bastille Limestone.....

 

[Dan]

Personally I think we get a bit uncoupling-heavy these days for the sake of being cautious. I'm sure the manufacturers of it sort the adhesive specifiers a drink out here and there for the amount of times it gets recommended on smallish newish floors.

But I might be wrong.

 

[Lee@emctiles]

doesnt BS state that an uncoupler is required on heated screeds and natural stone?

Id definitely use one anyway.

 

[Dan]

Not BS I don't think no. I don't think so anyway. Might be totally wrong.

@Ajax123 ?

 

[Just Rizzle]

<removed a personal dig at another member>

shifted 2crates so far and there still going strong but lets be fair there not going to last for ever but saves carrying them

 

[Ajax123]

doesnt BS state that an uncoupler is required on heated screeds and natural stone?

Id definitely use one anyway.

yup. I shall find the section and post it. Think it i 5385 Part 3 but cant remember.

 

[Dan]

I stand sit totally corrected.

Thank goodness there is a bit of competition now then because pre-2009 there was pretty much just Ditra?

 

[Dave]

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.

 

[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.

 

[Dave]

All the Bastille floors I've done , I have used Mapei Ultra colour grout.

It's s nice coarser grout than most and most importantly for me , rapid setting. Which helps keep a nice flush joint.

And comes in loads!! Of colours.

As for the expansion strip if one is required , then either to suit tile colour or grout , not many options as you say when you need deep ones.

You could make your own cold joint if you get get suitable metal flat trims of that depth and then use Mapeis matching Silicon to the grout , setting a min 10mm cold joint.