Tiles falling off walls

[ladyeleanor]

Hi,

I'm in the process of tiling my bathroom. The tiles I'm using are 600 x 300 slate and I am using a two part adhesive (Unibond). I'm now on my third attempt as each time the adhesive dries, the tiles move away from the wall and therefore don't stick. I'm tiling onto primed plywood, well fixed, and i've now tried two different brands of two part adhesive.....what am I doing wrong? On my last attempt I PVA'd the back of the tiles but this doesn't seem to have improved anything. The adhesive is staying on the wall, not on the tile?????

Many thanks.

 

[tictic]

1..plywood is no good for walls(rip it done)
2..uniBomb is crap(get the good gear,as its large slate)
3..NO PVA (use arylic primer,but not onto the tile)
4..thought about employing a Tile Fixer??

 

[jctilingservices]

Hi,

I'm in the process of tiling my bathroom. The tiles I'm using are 600 x 300 slate and I am using a two part adhesive (Unibond). I'm now on my third attempt as each time the adhesive dries, the tiles move away from the wall and therefore don't stick. I'm tiling onto primed plywood, well fixed, and i've now tried two different brands of two part adhesive.....what am I doing wrong? On my last attempt I PVA'd the back of the tiles but this doesn't seem to have improved anything. The adhesive is staying on the wall, not on the tile?????

Many thanks.

DONT use PVA anywhere in connection with your tiling, could you let us know exactly what the adhesives are that you have used, Unibond is crap though, you should have used a decent trade adhesive such as have you primed the plywood with PVA?

What thickness is the ply you have used also is it WBP ply?


Have you sealed the tiles or were they pre sealed, slate can/will absorb your adhesive and so mark the edges and faces of the tile

What size notched trowel are you using that size tile?

Did you back butter the tile?

You should really have primed with an SBR and used an adhesive such as Bal single part flexi.

come back with those answers and you will get a more definate answer,sorry i cant answer straight away for you, too many unknown factors at the minute

 

[jctilingservices]

1..plywood is no good for walls(rip it done)
2..uniBomb is crap(get the good gear,as its large slate)
3..NO PVA (use arylic primer,but not onto the tile)
4..thought about employing a Tile Fixer??

looks as though we were replying at the same time Davie mate and we agree about unibomb

 

[tictic]

1..plywood is no good for walls(rip it done)
2..uniBomb is crap(get the good gear,as its large slate)
3..NO PVA (use arylic primer,but not onto the tile)
4..thought about employing a Tile Fixer??

looks as though we were replying at the same time Davie mate and we agree about unibomb

alright jimmy hope yer good mate...had a wee shot of the rubi ti 660 flatbed earlier mate the pull system ...nice cutter.....but its a sigma rip off... ..was impressed with a few things on it tho

 

[jctilingservices]

1..plywood is no good for walls(rip it done)
2..uniBomb is crap(get the good gear,as its large slate)
3..NO PVA (use arylic primer,but not onto the tile)
4..thought about employing a Tile Fixer??

looks as though we were replying at the same time Davie mate and we agree about unibomb

alright jimmy hope yer good mate...had a wee shot of the rubi ti 660 flatbed earlier mate the pull system ...nice cutter.....but its a sigma rip off... ..was impressed with a few things on it tho

so you still wont be converted from sigma mate?

 

[tictic]

liked the exstension/support arms(2 of them)..
widder base also..
liked how you can disconnect and reconnect the cutting wheel..(clip system)..

although
heavier in weight/bulker..
the adjustiable height only raises by 3mm..
and still to many parts on it..lol..

but a good cutter....so will wait till(if ever) my trusty sigma"s ever falls apart(and boy do they take some abuse).....maybe...

but rubi have just more or less copied the sigma,so their sales may have falling ever so slightly...

 

[Richard C]

what am I doing wrong?

Just about everything m8. Nothing I can add to what the guys have already said really except go read the Tiling Sticky & Forum Archive posts; too late in your case as it WOULD have saved you a lot of grief & expense .

 

[ladyeleanor]

Hi,

Thanks for the comments, in answer to your questions:

The plywood is 12mm WBP.
The tiles haven't been pre sealed.
I'm using a 6mm notched trowel.
I did back butter the tiles.

I had been advised by the tile company to coat the back of the tiles with PVA!

Would I be better replacing the ply with plasterboard, and if so would I be able to tile straight onto that with such large tiles, or would I need to have it skimmed? Although the adhesive is sticking fine to the wall?

Thanks.

 

[Richard C]

The plywood is 12mm WBP.

Never use ply as a tile base on walls, I would tear it down & start again.

The tiles haven't been pre sealed.

Slate tiles are not a good choice for a tiling novice; adhesive/grout can stain some slate tiles & it’s advisable to seal both the tile edges & face before you fix. Ultimately you should seek advice from your particular tile manufacturer/stockist but if they told you to use PVA on the back of the tiles, maybe that’s not a good idea.

I'm using a 6mm notched trowel. I did back butter the tiles.

Too small; with flat walls you could use a thin solid bed notch trowel - 10mm notches, 5mm deep, at 12.5mm centres; but with tiles that size & I would use a thick solid bed round notch trowel; 20mm notches, 10mm deep, 28mm centres.

Use a quality trade cement powder flexible adhesive Rapidset, Natural stone or single part flexible but with the emphasis on “quality”; BAL, Ardex, Mapei (but not the stuff in BNQ), Webber etc. Assuming your tiles are grey slate, use grey adhesive.

I had been advised by the tile company to coat the back of the tiles with PVA!

Whoever advised that is a total idiot; standard PVA is not waterproof & will re-emulsify if it gets wet; use it in wet areas where there is a good chance the tiles will fall off the wall, assuming you can get them to stay up there in the first place .

Would I be better replacing the ply with plasterboard, and if so would I be able to tile straight onto that with such large tiles,

No, use a waterproof tile backer board; very unlikely plasterboard will support tiles of that weight; max 32 kg/sqm including up to 4 kg/sqm for the adhesive.

or would I need to have it skimmed?

Not necessary & a bad idea; plastering will reduce your acceptable tile weight further to 20kg/sqm (including adhesive), almost certainly not enough for your tiles.

Although the adhesive is sticking fine to the wall?

Well at least it stuck to something other than your hands .

 

[jctilingservices]

follow everything Rich has said and you wont go wrong

 

[festive]

HI ladyeleanor,

i had a similar issue to you and also deservedly got a right *******ing on here when i revealed my methods/materials used

Saying that i used a premixed unibond adhesive and it just didn't like my porcelein tiles, it was sticking to the walls but coming away from the tiles on setting.

I switched to a much wetter waterproof fix n grout adhesive and they stuck like sh't. And they're still there now (well they were this morning). Im not going to reveal the make for the fear of more rapid machine gun fire

Edited to add i do in no way recommend doing what i did! Listen to the experts on here, definately check you have the right adhesive for your tiles.

 

[Richard C]

Fix n grout products have serious limitations, they may have worked in this case but who knows how long they will stay up there. They are basically DIY crap & no professional tiller would ever use them; I advise you stick with quality trade products as listed.

 

[festive]

Oh for sure Richard.

<pedantic rant!> We had a 'proffessional tiler' tile our kitchen floor and he royally ****ed it up, i bet my bathroom tiles last longer I prefer to use the terms expert/skilled </pedantic rant!>

 

[Richard C]

Oh for sure Richard.
<pedantic rant!> We had a 'proffessional tiler' tile our kitchen floor and he royally **** it up, i bet my bathroom tiles last longer I prefer to use the terms expert/skilled </pedantic rant!>

If he fecked your kitchen up, he obviously didn’t know what he was doing. Just because someone tells you they can do something doesn’t make them any good at it . You can’t trust anyone & you need to choose any trade very carefully, either go on personal recommendation or after seeing examples of their work.

You obviously picked the wrong guy for your kitchen but then you compounded the mistake by using the wrong materials in your bathroom! Personally, I wouldn’t put too much faith in the “fix-n-grout” going the distance if you used it in wet areas but maybe you like retiling your bathroom every 3-5 years.