Porcelain Tiles Advice

[SteveUK]

Hi all,

I'm a DIY-er who's looking to lay a hall floor with black and white polished porcelain tiles in a chequerboard pattern (the wife's choice...had better get some brownie points by the end...).

Before you ask, yes, they are from B and Q :yikes:.

I've read the posts about ensuring that the wax has been removed before sealing. I've looked at the tiles and the white ones are shiny but I suppose the dark ones are a little dull and may have wax on. Is there a definitive way to tell?

Anyhow, the main part of this post is to ask whether what I am thinking of doing is completely mad.

We would like the tiles to be very close together to make the chequerboard pattern more effective. Now, the tiles aren't rectified but I got a couple of packs out last night and laid them out and they fit very well without any gaps in between. What I was thinking was to lay them out in this way, but as I am laying them, add a thin line of clear silicone in between the tiles and then sandwich them together, thereby giving a seal in between the tiles.

What do you think? Do you think the silicone would damage/stain the tiles? Am I mad?

Thanks, Steve

 

[diamondtiling]

I would not do that steve, the grout is there for a purpose, you can get a clear epoxy grout instead of cement based, epoxy is straight forward but i have used it so many times so I would say that, butt jointing tiles is not a good idea.
As for the wax on the tiles your local tile supplier should be able to supply you with a product to clean it off, if its on you should be able to see it.
Check the tiles for batch and shade numbers because if you are determined to close the grout lines up then the last thing you want are different sized tiles, even by 1mm will throw everything out.

 

[SteveUK]

Thanks for the reply. I've read that epoxy grout is really difficult to work with (well, for us DIY lesser mortals...:smilewinkgrin.

What are the drawbacks with butt-jointing? 'Just' the size differences or might there be problems with expansion, etc.?

 

[diamondtiling]

Expansion is one factor, if you look at the floor of a supermarket with its terrazzo tiles there are expansion joints everywhere to cope with such a small gap, Size is another, Imm at one end of a room can become 5plus at the other, I have laid many chequer pattern floors and always had a small grout line, its there to protect the edges and to keep water out for cleaning purposes, you should be using flexible adhesive for your tiles

 

[SteveUK]

Small grout line it is then :smilewinkgrin:

Yeah, I have been eyeing up some porcelain adhesive with flexible additive. I was going to use a grey grout and was therefore worried about it 'leaking' into the white tile. I suppose I could use tile sealer on the sides of the tiles, as well as the faces?

What do you use for a thin grout line? Can you get smaller spacers or have you got another method?

Thanks again!

 

[grumpygrouter]

What is your floor made of? If it is timber then a narrow grout joint may be a bit risky!

 

[SteveUK]

Yes, it is a (stiff) wood floor. I presume I need to use a flexible grout as well as adhesive.

 

[diamondtiling]

you could overboard the floor with hardibacker or "no more ply", The smallest grout line I have put in was 2mm, get spacers and peg the tiles as you go, dont put the spacers in the grout line, lift out when dry before grouting, make sure the sub floor is really sound and screwed down, you will be fine with the narrow grout line if you prepare the sub floor properly

 

[SteveUK]

I was going to use 6mm ply to level things off. Is No-more-ply worth using if the tiles aren't going to get particularly wet?

Looks as though I'm going to have to do some more research about what adhesive/grout/sealer to use. Will come up with a list, see what you think..

 

[DHTiling]

No need to worry about bleeding on tile edges.....porcelain has a very low water absorbance rate...

 

[grumpygrouter]

I was going to use 6mm ply to level things off. Is No-more-ply worth using if the tiles aren't going to get particularly wet?

Looks as though I'm going to have to do some more research about what adhesive/grout/sealer to use. Will come up with a list, see what you think..

Absolute disaster, don't do it!!! backerboard or much thicker ply!

 

[SteveUK]

Ahh..OK. I'll look round for some local suppliers (Birmingham). Out of interest, why not 6mm, will it 'rise up'?

I was thinking of ripping out the floorboards and putting down 18mm ply but if backer board if the way to go, I'll do that.


Thanks.

 

[grumpygrouter]

6mm ply is too flexible, no matter how closely together you screw it down. There is far too much potential for getting voids underneath which can lead to cracking.

Ripping out the floor boards, putting in noggins at 300mm centres and then laying the ply is an excellent way to go! Screw the ply down to the joists and noggings and you will have a very solid floor!

 

[SteveUK]

Yeah, that's what I was thinking with regards to the noggins, etc. Food for thought! The only I'm no sure about is the fact the stairs are resting on the floorboards. I'll have a look under the floor and see what's what!

Cheers.

 

[SteveUK]

Hi guys,

Have finally got round to starting this (have been finishing off the utility room!). I ripped up for the floor at the weekend, packed the joists where needed, put plenty of noggins in and replaced the floor boards with 18mm ply. Now the floor is solid with no movement at all :smilewinkgrin:

Here are the products I am thinking of purchasing:

Sealer:
LTP MPG Sealer to seal the tiles, two coats before laying and one after grouting

Adhesive:
Mapei Keraquick, along with Mapei LatexPlus as it is a wooden floor

Grout
Mapei Ultracolor Plus (Grey)

How does that sound? The thing I'm unsure of is that although people have said Keraquick and Latexplus are OK for Porcelain on wood in this forum and it says so in the Screfix catalogue, I haven't seen Mapei explicitly state that in any of the data sheets.

Therefore, I'm not sure 1. that it's OK and 2. whether I should prime the ply before laying the adhesive?

Cheers, Steve

 

[Time's Ran Out]

In post 1 you said the tiles were B&Q polished porcelain - what size?
Now you have secured the 18mm plywood to the joists and noggins - what material are you going to overboard it with before you stick the tiles down?
With certain tiles you should not and will not be able to butt joint the tiling especially on a wooden substrate. Any movement will chip the tile edges as deflection takes place.
You will spend more time cleaning silicone off the surface of the tiles if you try to seal the tight joint.
The smallest tile joint will be 2/3mm and that will be dependant on the nominal size of tiles used.
Answer a couple of these pointers first and just check to see if any one else has a view on overboarding!.

Timeless John.

 

[Deleted member 1779]

And if you're fitting things like radiators etc then dont forget your porcelain tile holesaws.

 

[SteveUK]

Thanks for the replies.

John, I knocked the butt jointing on the head after feedback from the guys on here (strangely, some of the replies have disappeared - ooo, now they're back! DiamondTiling's posts were not there yesterday for some reason!) and so will be putting a grout joint in (the tiles are 400x400mm
). Would like to go with 2mm if I can get away with it. I suppose that as it's a DIY job, if I have to re-do a couple of joints in a year's time because the grout's cracked then it wouldn't be the end of the world. I realise that you can't do that if you're a pro as you would be constantly going back to old jobs!!

I ripped up the floorboards and replaced with ply so that I wouldn't have to overboard, as per Grumpy Grouter's suggestion.

Cheers, Steve

 

[Time's Ran Out]

Yes I noticed that there had been some editing done as well!
If you use a flexible adhesive and grout and the tiles are of quality size you will get away with a 2/3mm joint (I'd go 3mm for timber).
I missed the original thread posting but I'am at a loss to understand the reason for removing the floor boards and replacing just with 18mm plywood! As you will have a joint every 1200mm - even screwed through to joists - this will be an area for movement and cracking. I understand that certain adhesives are capable of tiling direct onto non tounge and grooved sheets, but the priciples that I follow would insist that an overboard to bridge the joint is required. IE. Hardie backer board/similar.

Its just my Opinion!

Timeless John.