Are large format tiles harder to work with?

[Adsibob]

We are considering large format Italian porcelain tiles by Marazzi for an open plan kitchen dining area. Probably in the 1200 x 2400 x 6 size. I agreed a price with my builder which just said I would buy the tiles and he would lay them - the contract doesn’t mention their size. Will this size tiles cause him any difficulty? Does it require special equipment to cut or lay? Most of the room is rectangular in shape, so it should be fairly straightforward, but there is a slightly curved diagonal wall that cuts into one corner of the room, so that might be a bit fiddly. @nod you seem to be in the tiling business, so would be great to hear your views. @Bored Shopper I think you might have laid some large format wall tiles based on a thread I was reading, so interested in your views too - as well as everyone else’s of course!

[nod]

Yes they are more costly as it’s a two man job and the bed needs to be thicker 20 mil 

He can hire a tile cutter that will cut across the tiles We tend to use a wheel for most of the heavy tiles 

Expect to pay 40m2 

 

You are right to pay the extra for Italian Tile leveling system won’t help if they are not flat 

There are some cheap imitations out there 

Edited March 7, 2021 by nod

[Bored Shopper]

Hi, yes we did - 5 panels on the feature wall in the bathroom as they were exact width of the ensuite!

Our tilers loved working with them as it's a big job done in half the time. Yes they do require a second pair of hands to lift and position, but doable and looks fantastic. They are not thick so not mega-horrible to maneuvre in position.

 

[Bored Shopper]

The other ensuite was done in 300x600mm tiles, not sure if these are large enough for your question

Edited March 7, 2021 by Bored Shopper

[Adsibob]

  On 07/03/2021 at 08:18, nod said:

the bed needs to be thicker 20 mil 

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Thanks @nod

i had only allowed 15mm, for a 6mm tile and 9mm for the underlay and adhesive

 

Attached is a diagram of my proposed build up. I might be able to borrow some mm from the screed and have thinner screed or I could have slightly less insulation. Or potentially increase the floor level, but it is potentially complicated to do that as they have already laid the foundations of the extension. What would you recommend:

 

[nod]

You will need 6 mil for the underlay 

9 mil tile would need 10 mil of adhesive making 24 mil build up 

A larger tile means less adjustment = Thicker bed 

[Adsibob]

  On 07/03/2021 at 10:20, nod said:

You will need 6 mil for the underlay 

9 mil tile would need 10 mil of adhesive making 24 mil build up 

A larger tile means less adjustment = Thicker bed 

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Sorry, I’m confused. What is the build up for a large format 6mm tile? 6 for underlay plus 20 of adhesive, so including the tile itself 32? Or does the 20 you mentioned originally include the 6mm underlay?

[nod]

  On 07/03/2021 at 10:47, Adsibob said:

Sorry, I’m confused. What is the build up for a large format 6mm tile? 6 for underlay plus 20 of adhesive, so including the tile itself 32? Or does the 20 you mentioned originally include the 6mm underlay?

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No

you will have 6 for the matting

Which ever tile you use 

20 adhesive for the 2.4 x 1.2 tiles 

[PeterW]

  On 07/03/2021 at 10:04, Adsibob said:

Thanks @nod

i had only allowed 15mm, for a 6mm tile and 9mm for the underlay and adhesive

 

Attached is a diagram of my proposed build up. I might be able to borrow some mm from the screed and have thinner screed or I could have slightly less insulation. Or potentially increase the floor level, but it is potentially complicated to do that as they have already laid the foundations of the extension. What would you recommend:

 

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Lose the sand - it’s pointless. Slab is also a mildly contentious issue with a few people too as it is a hang over from old build methods. 
 

With UFH do not lose the insulation or you’re just heating slab and ground below it. 100mm is bare minimum for UFH. 
 

With 55mm screed you’re in liquid screed territory anyway - how big is this space ..?? 
 

and do you really mean tiles that are 8 ft x 4ft..??!! 

[nod]

  On 07/03/2021 at 10:58, PeterW said:

Lose the sand - it’s pointless. Slab is also a mildly contentious issue with a few people too as it is a hang over from old build methods. 
 

With UFH do not lose the insulation or you’re just heating slab and ground below it. 100mm is bare minimum for UFH. 
 

With 55mm screed you’re in liquid screed territory anyway - how big is this space ..?? 
 

and do you really mean tiles that are 8 ft x 4ft..??!! 

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The largest I’ve used have been 200 x 1200 and they where very heavy 

[PeterW]

  On 07/03/2021 at 11:07, nod said:

The largest I’ve used have been 200 x 1200 and they where very heavy 

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Yeh I moved (not even installed ..!!) some 1200 x 1200 for someone and they were a 2 man lift and when they installed them they used some sort of crane / sucker system as they were 60kg each. 

[nod]

  On 07/03/2021 at 11:09, PeterW said:

Yeh I moved (not even installed ..!!) some 1200 x 1200 for someone and they were a 2 man lift and when they installed them they used some sort of crane / sucker system as they were 60kg each. 

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Very similar to moving glazing panels Two sets of suction cups 

[Adsibob]

  On 07/03/2021 at 10:58, PeterW said:

Lose the sand - it’s pointless.

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Architect tells me the sand is to make sure any imperfections in the slab don’t puncture the DPM. 
The area we are tiling is about 7.5m by 9.5m.

And yes I do mean 1200 x 2400. 
The tiles we are going for are a cement effect tile. The alternative is to lay microcement, but so that it didn’t crack my understanding  is that first the screed has to be fully cured before laying the microcement (so 55 days for 55mm to fully cure) and the underfloor heating must never to exceed 26 or 27 degrees at the floor. Is it me, or does that sound a little onerous/ stressful. Can the builder do other jobs whilst the screed is curing? When can one walk on the screed?

[Dave Jones]

  On 07/03/2021 at 09:30, Bored Shopper said:

Hi, yes we did - 5 panels on the feature wall in the bathroom as they were exact width of the ensuite!

Our tilers loved working with them as it's a big job done in half the time. Yes they do require a second pair of hands to lift and position, but doable and looks fantastic. They are not thick so not mega-horrible to maneuvre in position.

 

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sorry looks awful.

 

electric toilet with a visible cistern...

 

not my cup of tea at all.

[PeterW]

  On 07/03/2021 at 13:40, Adsibob said:

Architect tells me the sand is to make sure any imperfections in the slab don’t puncture the DPM. 

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Architect is from the 1950’s... 

 

Use a layer of 12mm EPS, it will crush to the imperfections and then provide additional insulation to the slab (which you will need with UFH) Sand is not required. Neither is a structural slab these days, do it with concrete and bin off the screed. 

 

Look at a resin floor - can’t remember who has it here but looks stunning ( @Bitpipe..?) and will allow you the finish you want in about 6mm. Or look at one of the commercial flow coats you can get,  all of which will be cheaper than your tiles as I’m pretty sure they will be £100/m or more. 

 

 

 

 

[Adsibob]

  On 07/03/2021 at 14:10, PeterW said:

Look at a resin floor - can’t remember who has it here but looks stunning ( @Bitpipe..?) and will allow you the finish you want in about 6mm. Or look at one of the commercial flow coats you can get,  all of which will be cheaper than your tiles as I’m pretty sure they will be £100/m or more. 

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I had understood that a resin floor is the same more or less as microcement and has the same installation difficulties regarding making sure it doesn’t crack when the UFH comes on.  But would be delighted to be corrected as we were keen on microcement until we found out about the risk of cracking with UFH.

The tiles we are going for are about £75 a square metre as we are getting a bulk discount - getting all tiles for entire project from the same place. I imagine a resin floor will be similar cost wise as the tiles plus the tiler’s costs. 

[Adsibob]

  On 07/03/2021 at 14:10, PeterW said:

Architect is from the 1950’s... 

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he’s actually only qualified in the last 3 years and his specification complied with NHBC guidelines which say blinding must be “sand or other fine material”, as far as I can see that wouldn’t include polystyrene, although I agree that that would give better insulation: https://nhbc-standards.co.uk/5-substructure-ground-floors-drainage-and-basements/5-1-substructure-and-ground-bearing-floors/5-1-16-blinding/

[Bitpipe]

  On 07/03/2021 at 14:10, PeterW said:

  On 07/03/2021 at 14:32, Adsibob said:

I had understood that a resin floor is the same more or less as microcement and has the same installation difficulties regarding making sure it doesn’t crack when the UFH comes on.  But would be delighted to be corrected as we were keen on microcement until we found out about the risk of cracking with UFH.

 

The tiles we are going for are about £75 a square metre as we are getting a bulk discount - getting all tiles for entire project from the same place. I imagine a resin floor will be similar cost wise as the tiles plus the tiler’s costs. 

 

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Look at a resin floor - can’t remember who has it here but looks stunning ( @Bitpipe..?) and will allow you the finish you want in about 6mm. Or look at one of the commercial flow coats you can get,  all of which will be cheaper than your tiles as I’m pretty sure they will be £100/m or more. 

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Yup very happy Sika resin floor owner here.

 

The buildup is about 6mm  (2mm of resin and 4mm of rubber crumb mat underneath). We have UFH underneath. The resin cures in about 24 hours and same again when painted with the top coat - 2-3 days in all. No restrictions on UFH temp and it is very nice underfoot - we are a no shoes inside house and everyone always says how pleasant it feels as there is a slight 'give' due to the rubber underneath. Pretty bulletproof also, only thing that's caused damage was some unattended bleach and even that is hard to see.

 

I needed additional buildup of ply as it was on a suspended wooden floor - 12mm + 9mm but on smooth solid surface like new self levelled screed then you'd be fine.

 

It was about £100/m2 all in so up there with expensive large format tile.

 

Looks great though  - we have a seamless ground floor surface which takes a quick steam mop to look as good as new and are very resilient to almost everything.

 

You can refinish it with the top coat if you tire of the colour or it gets damaged (no chips in ours after 5 years).

[Adsibob]

  On 07/03/2021 at 15:13, Bitpipe said:

 

Yup very happy Sika resin floor owner here.

 

The buildup is about 6mm  (2mm of resin and 4mm of rubber crumb mat underneath). We have UFH underneath. The resin cures in about 24 hours and same again when painted with the top coat - 2-3 days in all. No restrictions on UFH temp and it is very nice underfoot - we are a no shoes inside house and everyone always says how pleasant it feels as there is a slight 'give' due to the rubber underneath. Pretty bulletproof also, only thing that's caused damage was some unattended bleach and even that is hard to see.

 

I needed additional buildup of ply as it was on a suspended wooden floor - 12mm + 9mm but on smooth solid surface like new self levelled screed then you'd be fine.

 

It was about £100/m2 all in so up there with expensive large format tile.

 

Looks great though  - we have a seamless ground floor surface which takes a quick steam mop to look as good as new and are very resilient to almost everything.

 

You can refinish it with the top coat if you tire of the colour or it gets damaged (no chips in ours after 5 years).

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@Bitpipe this sounds very interesting indeed. I will look into it. I like a firm floor, but young kids so a bit of give might be beneficial. How does the firmness compare to say a firm suspended timber floor?

[Bitpipe]

It's a suspended timber floor underneath - OSB on pozi-joists with ply to give a dead flat base for the resin. Feels solid but with a softness - bit like posh Lino.

 

We've dropped glasses, plates etc on it and they virtually bounce. Very hygienic as there are no grubby gout lines. Good for the dog too as there were no issues with puppy accidents and the like.

[Ronan 1]

  On 07/03/2021 at 15:13, Bitpipe said:

The buildup is about 6mm  (2mm of resin and 4mm of rubber crumb mat underneath). We have UFH underneath.

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Bitpipe do the still use under mat when lad on top of a traditional screed ? Any chance you've got any pics? I was thinking about polished conc for around half the ground floor but this might be a better option

[PeterW]

  On 07/03/2021 at 14:37, Adsibob said:

he’s actually only qualified in the last 3 years and his specification complied with NHBC guidelines which say blinding must be “sand or other fine material”, as far as I can see that wouldn’t include polystyrene, although I agree that that would give better insulation: https://nhbc-standards.co.uk/5-substructure-ground-floors-drainage-and-basements/5-1-substructure-and-ground-bearing-floors/5-1-16-blinding/

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NHBC “standards” are crap, they are bare minimum and pretty much never adhered to. Go look at an NHBC signed off house then make your own mind up. 12mm Polystyrene more than meets the requirement, it is a pliable material which will support the DPM and prevent puncture, it has insulation value and also is quick and easy to lay. 

[Adsibob]

  On 07/03/2021 at 15:53, PeterW said:

NHBC “standards” are crap, they are bare minimum and pretty much never adhered to. Go look at an NHBC signed off house then make your own mind up. 12mm Polystyrene more than meets the requirement, it is a pliable material which will support the DPM and prevent puncture, it has insulation value and also is quick and easy to lay. 

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Okay, fair point. What compressive strength polystyrene would you recommend. Is 70kpa enough for a very firm floor? 

[PeterW]

EPS70 is under most floors anyway - works fine. 
 

 

[Bitpipe]

  On 07/03/2021 at 15:47, Ronan 1 said:

Bitpipe do the still use under mat when lad on top of a traditional screed ? Any chance you've got any pics? I was thinking about polished conc for around half the ground floor but this might be a better option

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No idea, where are you based? I can PM you the firm we used - would really recommend them as they do mainly commercial floors and the like, so did not have the 'lifestyle premium' of the fancier installers with the nice showrooms.

 

Will dig out a link to some posts with my floors in them however they do look just like this... 

 

https://www.sika.com/en/brands/comfortfloor.html#colors

 

 

Edited March 7, 2021 by Bitpipe