Advice on porcelain tile movement. Grout coming out of tiles.

[Wonkyfloor]

Sorry it’s a long one as looking for some advice please. We have had 50sqm of 600x600 porcelain tiles laid in our house which there is movement in the tiles. This has resulted in some lifting and grout popping out in places . Method that was used by them, 6mm ply fitted to existing floorboards then some sort of pvc primer/sealer? Rolled on top of the ply, underfloor heating mats were then laid on top of this and a self levelling screed over the top which finally the tiles were then laid on top of. Haven’t used underfloor heating yet as grout started popping out and tile movement also began happening before the time passed where we would be able to turn it on. Basically where we’re at is we have been back on to them to try and get this resolved. After some discussion and debates we’ve now been told that all existing tiles will be lifted, a new screed put on top of existing one and new tiles fitted on top but will use a different adhesive this time. So the question I have is will this actually work? Or is there anything that we should be aware of that hasn’t actually been done correctly with the method/materials and should be done differently?

 

[Bill]

It may work it may not but I would err on the side of not.

Firstly, the contractors need to cure any up & down deflection in the wooden subfloor. Priority!

From this point, a couple of methods are advisable but most certainly not is to use 6mm ply as an overboard to the floorboards.

Your contractor is not competent for the job.

p.s. any photos?

 

[Boggs]

Hi, do you have any pictures of the floor.

 

[Dumbo]

In reality it shouldn't work something has caused the tiles to let go and it is still there if you just level over the top . 6mm ply is insufficient the thickness required by British standards is 15 mm but even then most tilers will not tile to ply as it is not a great material to tile to .

 

[Flintstone]

By the sounds of if it's been done wrong and it's failing and they are trying to bodge it up by re fixing the tiles which have come loose. It's clear that they don't know what they are doing.

 

[Waluigi]

It’s the age old misconception that ply is still fine to use as an overlay material. It’s ingrained into some people’s brains because that’s the way it was done two decades ago and it’s still being passed down to people as being correct. 6mm though? That’s just crazy.

The work needs redoing properly IMO. There are plenty of tilers on here who do this type of work day in day out and they can advise. Large floors generally aren’t my thing so I’ll bow out and leave that to the experts to assist you. Good luck!

 

[Boggs]

To be fair we don’t know if they have used ply wood.
It might be No More Ply.

Did the original trades test the floor heating before the tiles where laid and did they let the floor cool down before tiling?
Or was the floor heating tested too soon after tiling by mistake.

 

[Dumbo]

They say they haven't used the heating . Heating should be tested using a multimeter and doing a continuity test checking the resistance .

 

[Boggs]

They haven’t but maybe someone has.

Sounds like thermal shock to me, pics will help.

 

[J Sid]

we can't really comment on this without know exactly what was done, what materials (ply, adhesive, primer, slc) were used.
so more info please, your builder should be able to do this and a full spec on what he plans to do next

 

[Dumbo]

They haven’t but maybe someone has.

Sounds like thermal shock to me, pics will help.

If the spec is what they say it is unless the tiles have been spot fixed im going to blame 6mm ply all day long

 

[J Sid]

how do u know the correct slc was used, adhesive was used.?
yes the ply is wrong, but may not be the cause of failure at the stage

 

[Dumbo]

how do u know the correct slc was used, adhesive was used.?
yes the ply is wrong, but may not be the cause of failure at the stage

To be honest you are correct but where I shop they only sell flex adhesive and levelling suitable for timber , ufh installations so yes I am making assumptions
My guess when they say change adhesive they are going to move to an s2 which probably still won't be good enough if the prep is wrong

 

[J Sid]

sadly we can't assume anything...... I've got a 100m2 floor onto ufh with a sub base of floor boards starting on Monday. I price for all the work but the electrician talked the customer into letting him do it as he will give a 25 year guarantee on his work. I've told him how I want the preparation done so I can tile it. He said the insulation boards don't need glueing or tapeing, the floor boards don't need screwing down first. What should I do? assume his method will be ok?

 

[Dumbo]

sadly we can't assume anything...... I've got a 100m2 floor onto ufh with a sub base of floor boards starting on Monday. I price for all the work but the electrician talked the customer into letting him do it as he will give a 25 year guarantee on his work. I've told him how I want the preparation done so I can tile it. He said the insulation boards don't need glueing or tapeing, the floor boards don't need screwing down first. What should I do? assume his method will be ok?

Don't really know what to say apart from no and leg it

 

[Waluigi]

When the tiles start to pop and crack the customers friends won’t be asking who did the prep work, they’ll be asking who tiled the floor.

 

[J Sid]

Don't really know what to say apart from no and leg it

if he doesn't give it to me in writing what he has done and what materials he has used, and they are fixed as per manufacturer instructions then I will have to leave it.
a week of maybe next week.

 

[Bathfix Bob]

Plenty of people using ply still, only today at a builders merchants I saw a tiler in a shiny new van loading up sheets of 6mm ply, heard them talking words to effect of get this down this morning etc.
They had a Dewalt nailer aswell.

 

[Brian the Tile]

Plenty of people using ply still, only today at a builders merchants I saw a tiler in a shiny new van loading up sheets of 6mm ply, heard them talking words to effect of get this down this morning etc.
They had a Dewalt nailer aswell.

I happen to be one of them tilers that still tiles on ply but not on 6mm (you might as well put cardboard down) surprising how many builders merchants sell it for floor tiling i always refuse ,i have never had a problem with the right thickness as long as it is laid correctly and the right adhesive and grout is used = no problems

 

[Waluigi]

Thinking about it. If I wanted to go and buy some ply for tiling tomorrow, I’d go and visit carpets and flooring in Camberley branch and buy some SP101. The only problem is that I think the thickest they stock is 9mm so I’d travel up the road to Buy some marine ply from Selco. Just checked. They only do 18mm and that’s £84 per sheet. I’ll stick with a TBB.

 

[Wonkyfloor]

Sorry for the late reply been trying to get it resolved with Christmas coming up and finally there’s a new tiler on the job. He is planning on taking it back to a blank canvas and using hardiebacker boards. The tiles are now lifted which was an easy job as apparently the adhesive hadn’t took to the tiles. I will attach some pictures of how it looks with the tiles lifted and what was underneath so far, if it is of any help or interest to anyone. Obviously everything isn’t visible yet but how it was laid was the first layer is ply then some sort of thermal primer put onto ply using a roller, heat mats, screed? and adhesive and finally tiles and grout.

 

[Wonkyfloor]

 

[Boggs]

Unbelievable!

 

[Wonkyfloor]

To be fair we don’t know if they have used ply wood.
It might be No More Ply.

Did the original trades test the floor heating before the tiles where laid and did they let the floor cool down before tiling?
Or was the floor heating tested too soon after tiling by mistake.

Hi thanks for your reply just to answer some questions. It was definitely ply as the joiner was project managing the full thing and bringing in the other tradesmen etc and it was the joiner who laid the ply and told us it was 6mm ply wood. Also advised us that British standards didn’t apply to our floor due to it being built up to at least minimum 12mm with the heat mats and screed. So as the tiles weren’t directly laid onto the 6mm ply wood it didn’t count basically. Also no nobody tested the heat mats infact 2 of them arent even live yet as tiles started popping and the electrician said from his point of view it was pointless connecting them up as the floor would need to come back up.

 

[Wonkyfloor]

Unbelievable!

Sorry if I’m sounding stupid here but I know absolutely nothing about tiling so I’m having to basically take their word for everything. From what you can see in the pictures what would be your professional opinion. Thanks in advance.

 

[Spare Tool]

Its wrong from the ply upwards, the 6mm ply is doing absolutely nothing, there should be insulation boards below the ufheating, hardibaker would be ok but 10 or 12mm insulation boards glued and screwed would be better IMHO, the mats should have then been leveled over to make a flat (even if not level) floor to tile to, using flexible materials throughout.
Can't understand why the previous tiler would notch trowel the floor then daub a few blobs of adhesive down and plop a tile on, its no wonder it a catastrophic failure..

 

[Wonkyfloor]

Its wrong from the ply upwards, the 6mm ply is doing absolutely nothing, there should be insulation boards below the ufheating, hardibaker would be ok but 10 or 12mm insulation boards glued and screwed would be better IMHO, the mats should have then been leveled over to make a flat (even if not level) floor to tile to, using flexible materials throughout.
Can't understand why the previous tiler would notch trowel the floor then daub a few blobs of adhesive down and plop a tile on, its no wonder it a catastrophic failure..

Thanks for taking the time to reply and explain how things should be done and what has gone wrong. It’s took us over 8 weeks just to finally convince the guy who was the project manager that the floor needed lifted and redone. The only problem was I didn’t know what actually had to be done or what was wrong, just that the floor right through the downstairs of the house was a mess and falling apart like a domino effect.

 

[Spare Tool]

Thanks for taking the time to reply and explain how things should be done and what has gone wrong. It’s took us over 8 weeks just to finally convince the guy who was the project manager that the floor needed lifted and redone. The only problem was I didn’t know what actually had to be done or what was wrong, just that the floor right through the downstairs of the house was a mess and falling apart like a domino effect.

Would think its failed so quickly because of the blobs of adhesive, but would probably have all failed eventually due to the under lying prep starting with the ply..

 

[Boggs]

This is the perfect example of poor workmanship.
Poor prep, no back skim and dot and dab.
As has been said above bound to fail from the ply up.
Still a bit odd that the adhesive hasn’t taken to the tiles at all though.

 

[Wonkyfloor]

This is the perfect example of poor workmanship.
Poor prep, no back skim and dot and dab.
As has been said above bound to fail from the ply up.
Still a bit odd that the adhesive hasn’t taken to the tiles at all though.

That’s what confused me as I thought regardless of how bad the workmanship was adhesive would still stick. This is only one room that has been lifted so far. Still to see the rest but I imagine it can’t be any worse than what has been seen today.
But one thing that has baffled me is do you have any idea as to why some of the floor is a dark grey then the other section of the floor is a lighter colour?
Also going to try be a bit more observant this time round, any suggestions would be greatly appreciated of what I should be looking out for. Today hardiebacker boards have now been screwed down in living room and as far as I have managed to gather the plan is underfloor heating mats will be laid on top of these boards and then tiles fitted on top of the mats.
Thanks very much for all advice on this thread as my husband is working and it’s myself trying to deal with it. I get the feeling that they don’t want to explain anything to me and any concern i raise are basically disregarded. Pretty much the same as when I questioned the 6mm ply and was told that it didn’t apply to my floor due to it being built up with underfloor heating and screed so they weren’t laying directly on top of the ply wood. Sorry for bombarding yourself and the thread but I’m just feeling out of my depth now to be honest.