Porcelain floor tiles

[lewisloo]

Hi
I have just finished my kitchen and the floor is the next project, I have layed 18mm ply over the orginal floor boards and bought the tiles (porcelain floor tiles), in my haste I picked up a couple of tubs of adhesive and grout for wooden floors, it wasnt until I got home and read the tub and realised this is not suitable for porcelain floor tiles, now im stuck on what to use, having looked on the B&Q website there is a unibond cement which is suitable for porcelain tiles, is this the best option? ,and can I still use the tubs I have bought for grouting? any help will be much appreciated
many thanks
p.s can a grip and fill adhesive be used?

 

[Dontiler]

Don't think it's good idea to tile straight on to ply, I would still glue and screw hardibacker, 6 mm will do it if floor is not bouncing, other option is to use uncoupling membrane

 

[Rich]

I agree with Dontiler. Also I wouldnt bother going to B&Q for the adhesive, Is there a Tile Giant near you? If not there must be a topps. Go in there and talk to the guys in there. If its Tile Giant it will be Mapei (my personal fav) or if its topps it will be BAL. You will want 6mm backer board like no more ply or Hardie (provising there is no deflection in your floor) and a single part flexible cement based adhesive. I would take the fix and grout back to the shop and pick yourself up some suitable floor grout from said suppier. Might work out slightly more money but I promise you it is worth it.

 

[aflemi]

Don't think it's good idea to tile straight on to ply, I would still glue and screw hardibacker, 6 mm will do it if floor is not bouncing, other option is to use uncoupling membrane

Why not tile onto 18mm ply overboarding? Sounds pretty good to me as it is.
Only point I would make is to check the adhesive you use doesn't recommend you seal the underside of the ply, like BAL.

 

[Rich]

It is always better to tile onto a backer board rather than straight on to ply.

 

[White Room]

If the original floor boards are good and no bounce why not just use 6mm hardie

 

[aflemi]

If the original floor boards are good and no bounce why not just use 6mm hardie

ply is down already.

 

[White Room]

OH right

 

[aflemi]

It is always better to tile onto a backer board rather than straight on to ply.

Can you expand with reasoning please?

 

[Rich]

I dont like tiling on to ply given the choice, tile backerboards are designed to be tiled onto, ply is not.

• Ply will swell with moisture, this can cause tiles to lift or grout to crack
• If ply get damp but not enough to lift tiles, it can stain the grout
• A lot of ply is treated with fire resistant chemicals that stop the adhesive bonding
• Most ply is NOT suitable to tile onto

Backer boards will do none of the above.

 

[jubba]

Just done my kitchen floor, made sure floorboards where fixed well, overlayed with 9mm ply with screws every 150mm, primed with granfix acrylic primer then used granfix superflex adhesive. Suitable for porcelain & says can be laid directly onto floorboards, so your 18mm should be more than ample. (as long as its solid)

Only been down a week, but Jumped up an down on them a bit (LOL), and feels pretty soild.

 

[aflemi]

I dont like tiling on to ply given the choice, tile backerboards are designed to be tiled onto, ply is not.

• Ply will swell with moisture, this can cause tiles to lift or grout to crack
• If ply get damp but not enough to lift tiles, it can stain the grout
• A lot of ply is treated with fire resistant chemicals that stop the adhesive bonding
• Most ply is NOT suitable to tile onto

Backer boards will do none of the above.

The OP has already laid the ply (18mm, which is thicker than most people seem to use, 12mm generally appears to be an acceptable minimum).
I must have read hundreds of posts regarding tiling onto ply and, maybe I'm wrong but, on the contrary, it seems totally acceptable as being suitable to tile onto. I'd be interested to hear other tilers views on this??:bigear:

 

[White Room]

I do work for plumbers and they love ply, they can be hard work at times but I have to work with it

 

[Richard Edwards]

I do lay on ply - always 18mm WBP grade and seal both sides with acrylic primer. I always use Bal two part fast flex - which has already been stated on the Forum is very very expensive. - Actually I use 'Butech Tile to Wood' at trade is 60% of the cost and is the same - exactly! Always ensure boards under ply are very stable and pump in a lot of screws - usually 200mm centres or less and along all board joints and doorways at 100 mm centres - It a lot more difficult to add some more screws once the tiles are down. !!

Otherwise I use backerboards, either Hardie/Lux/Wedi or similar cheaper ones depending on the application.

:8:

Hope this gives you confidence

 

[lewisloo]

Hi
thanks for the feedback, quick update I did use marine ply (exterior) then gave it 2 coats of waterproof pva, so hope this works!!

 

[Aston]

there will be times when you have to fix tiles onto ply. as beam say's plumbers AND builders always ssem to go for it. mostly down to unintentional ignorance and being set in their ways imho..

it doesnt really matter if you used 100mm thick ply (if they made it ) and screwed it every 50mm, its still has all the concerns that dylante listed. as i wrote yesterday, we need to be progressing forward if we can and that means educating our clients, builders and in some instances, other tilers.....as i said at the begining, sometimes you'll have no choice but always explain why, ply is not a stable substrate in the same way as a tile backer board is.....

 

[Aston]

Hi
thanks for the feedback, quick update I did use marine ply (exterior) then gave it 2 coats of waterproof pva, so hope this works!!

waterproof pva??

 

[Rich]

The OP has already laid the ply (18mm, which is thicker than most people seem to use, 12mm generally appears to be an acceptable minimum).
I must have read hundreds of posts regarding tiling onto ply and, maybe I'm wrong but, on the contrary, it seems totally acceptable as being suitable to tile onto. I'd be interested to hear other tilers views on this??:bigear:

We all Have to tile onto ply if we want to stay in business. My point was if he could have over boarded with a backer board than I would advise it. As he cant, it doesnt matter. Ply is not an ideal substrate to tile onto for the reasons I have listed above and another thousand that the guys on here could add. We only tile on to the stuff because builders, plumbers, customers and
(unfortunatley) some tilers dont know any better. Brilliant post by Diamond, I couldnt agree more. It is down to us (professional tilers) to tell people what needs to be done to ensure a sound installation.

 

[Rich]

Hmmm...PVA??

 

[aflemi]

We all Have to tile onto ply if we want to stay in business. My point was if he could have over boarded with a backer board than I would advise it. As he cant, it doesnt matter. Ply is not an ideal substrate to tile onto for the reasons I have listed above and another thousand that the guys on here could add. We only tile on to the stuff because builders, plumbers, customers and
(unfortunatley) some tilers dont know any better. Brilliant post by Diamond, I couldnt agree more. It is down to us (professional tilers) to tell people what needs to be done to ensure a sound installation.

Sorry, I can't see Diamond's post on this thread? I am always willing to learn from more experienced tilers and am very interested in your views. It's just that I can't remember reading anywhere previously that ply was regarded in such a negative way. That's why I'm interested to get a broad coverage of input if I'm to change my practices.
Do people have floor tiling failures because of ply being used that they can identify? I must admit I thought the main advantage of BB over ply on floors was the thickness. I don't think even Hardiebacker make a big point of this inherent weakness in ply compared to BB in their publicity.
Still interested to hear others experience of this??

 

[Rich]

Oops!! I meant Aston, Sorry

Its not just the thickness (although that is a big advantage). I spent months putting right an entire site on two different occasions. The first time was 32 5 bed houses, every single kitchen floor (ply) lifted and I had to put it all right. I didnt tile it in the first place so I cant be sure if it was done correctly. The second time was another site of 19 4-5 bed houses, same thing but all the bathrooms (ply). Same again, I wasnt there when the floors were layed so cant say that they were dont correctly but has made me very unsure of ply floors. Why dont you put a new thread up and get some feed back on other guys views?

 

[Ken Bruty]

Hi

I always worry about tiling onto ply, I'm always expecting the dreaded phone call with a problem. If I have to do it, I always advise my customer that there is a risk involved with doing so, and the product I use is Weber Rapid plus adhesive mixed neat with Weber AD250 primer, it's absolutely unbelievable how strong the bond is, you never ever get a full tile lifted after it's stuck and cured. I always use hardie or ditra matting if possible.

All the best

Ken

 

[Scott]

I've always used ply and never had a problem or a call back, (Ultra primer and ultra 2 par flex)

However as mentioned its all down to education and i will be using more hardie now

 

[TrumpersUnited]

Hi

I always worry about tiling onto ply, I'm always expecting the dreaded phone call with a problem. If I have to do it, I always advise my customer that there is a risk involved with doing so, and the product I use is Weber Rapid plus adhesive mixed neat with Weber AD250 primer, it's absolutely unbelievable how strong the bond is, you never ever get a full tile lifted after it's stuck and cured. I always use hardie or ditra matting if possible.

All the best

Ken

As long as the 18mm plywood is screwed down every 200 or 300mm to the joists then weber rapid plus and ad250 would be my choice. If the joists span are bigger you'll have to put in extra noggins.

 

[Richard Edwards]

As stated previously - Ply does and can have it uses and ultimately its down to you as a fellow professional. Installed correctly and tiled with the best 2 pack adhesives it will be fine. I've probably overlayed 50 bathroom floors with this system and the 'Correct' ady. I've also chosen to use Wedi or Lux boards and sometimes Hardie if the application would be better suited to the latter. Never had a recall on any floor whatsoever. The only issues is when I am called in to sort out remedial problems caused by other tilers and when you start to lift the tiles - it is nearly always due to either (a) poor installation techique or (b) inappropiate ady for the substate / stability etc.

Ply if want to - Paul McCarty !