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

[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