porcelain floor tile movement

[Eduardo]

Hi Bugs183,
The tiler is taking the floor up now. I have taken a picture. Is this the dabndot technique he's used?
Many thanks View attachment 50917
The tiler has told me he has done it this way because the floor was not level!

If the builder use selfleveling for what reason do this?This product is for leveling the substrate. If the tiler find the floor not in level,use the adhesive in this way is not the best solution.The adhesive is just for stick,not for make the level,for make the level exist many special products

 

[bugs183]

Sorry about my rubbish typing there, doing it with my podgy fingers on my phone.

 

[Stef]

I should have went too the bookies & placed a bet!!

Knew this would be the case.

Sorry but that whole floor needs lifted & redoing.


It looks as though the tiles are laid on top of a self level screed,

Usual from a builder that they can't even get a self level screed level!!

 

[kaide]

Hi, Robson, Eduardo and Bugs183,
We really appreciate all your help.
The tiler had used the dot and dab technique over the whole kitchen because he says it was not level. If he knew this, why didn't he tell his boss. There is a gentle slope from one end of the kitchen to the other. There is a difference of at least 1 inch from one end to the other. The tiler says I caused the dot and dabs to fail because I put the under floor heating on high. I had put the under floor heating on 3 weeks after the tiles were laid. I now know you turn it up gradually by 5 degrees each day from reading the forums. The self levelling concrete had not adhered to the filebacker boards or the plywood. It had become a floating floor. They don't know why this has happened. We don't know if the plywood had been primed with latex primer. Also, they wonder if they had a faulty batch of self levelling concrete. The tiles on the concrete end of the kitchen came up too easily as if the adhesive had failed.
Now the whole floor has been taken up, the builders are going to strengthen a couple of joists and placed 12 mm plywood over the existing boards. They are then going to prime the boards with latex primer, put the electric under floor heating mat and then level the floor with self levelling concrete. We don't think it will be completely level and be a slight slope. We don't mind as long as the tiles don't move or become damaged.
The tiler will not reassure me that he will not use the dot and dab technique, when he comes to re-tile the kitchen.
Our builder tells us that the vast majority of professional still use the dot and dab technique. Is he correct? He may be reading this site as he has told us that he has been reading them to help him understand as to what has happened to our floor.
Any advice greatly and much appreciated. I will post a photo of our floor as it is now. The additional plywood has not be laid as they are sorting out the joists tomorrow.

 

[widler]

Now, let the fun begin

Take a photo of the substrate as well , what he has tiled on !

Oops thought the photo was the back of the tile on my phone, now I see its the floor

 

[Stef]

You are in a bit of a pickle!!

I hope your builder reads this

"It is NEVER acceptable under any circumstances to dot dab floor tiles", or any tiles for that matter.
Floor tiles "Must" have 100% coverage.
No if buts or maybes...

Putting the heating on as you did wouldn't have helped as it sounds as though you have thermal shock but those tiles would have failed regardless because of the laying technique.

Tell the builder to get a pro tiler in if this tiler cannot guarantee the tiles won't be dabbed again.

There's a lot more issues than just the tiling, the substrate is not up to scratch. 12mm ply?? BS states 15mm minimum & that's not going between 2 different floor structures.

You will get a lot more info when the troops start getting back in from work

 

[Marksmithtiling]

Dot and dab never ever ever, if thats what the tiler says he may well do again then DO NOT LET HIM TOUCH THE JOB. I am sure there are guys on here near you that can help you out.

 

[CJ]

As above.

minimum 15mm ply. Primed

Flexible self levelling compound

Expansion strip between screed/ply

Flexible adhesive & grout

Pro tiler......not the original clown.

 

[binsy]

Forget the tiling, is it my bad eyes or is there an acute shortage of screws in the boards?? If the boards aren't laid properly what chance have you got with the tiling??

 

[bugs183]

Oh dear...
Firstly i don't like picking holes in anyones work, anyone can be an expert if something goes wrong, but..

As Robson says, dot and dab is never acceptable ever ever ever etc. No builder should except a tilers work that has any hint of dot and dab, and for him to be unable to gaurentee it won't happen is unforgivable, he should be kicked off site, he's wasting your time and money and the builder' reputation. Maybe the majority of 'tilers' do that because there are lots of people claiming to be tilers that don't have a clue, or just don't care, it gives us guys who care a bad name and takes work away from us.

The tiler hasn't explained to you the difference between 'level' and 'flat'. If you hold a CD case in your hand it is 'flat', but if it is tilted then it isn't 'level'. Many floors can't be leveled as you could get huge height differences between door openings etc, but should always be flat. I see he got the floor flat but was he trying to 'level' it too, explaining why he tried to raise the tiles by dot and dabbing, if the floor wasn't 'flat' enough he should have sorted it before tiling.

Why didn't the leveling compound (not leveling cement) stick to the boards? My guess is it wasn't quality gear and certainly wasn't primed.

The tiler should be preparing his own floor, not the builder. The tiler should come and say if he is a happy with the prepared substrate, both the concrete and the wood, if he isn't happy he should voice his concerns and explain what needs to be done, and not proceed until it is done, this floor will be his resoncibilty.
Then he would prime as required lay the under floor heating and level over the top. This is his job, not the builders mate, why would he get it flat and why would he care if he didn't.

Then the next day proceed with tiling if he deems the floor 'flat' enough to take large format tiles, if not add another layer of leveling (or self smoothing compound as it is often called now), to make it flat. When he lays his tiles he will comb the adhesive onto the floor, back skim the tiles and not, ever ever ever dot and dab the tiles to the floor, if a tile is high or low he adds or removes the adhesive needed all over the tile so that the adhesive is solid bedded into it. Any voids are a weak spot.

You did cause the dot and dab to fail, because you walked on it and it was not laid well enough in the first place!!!

 

[kaide]

Thanks Robson,
You've given me a lot of reassurance about the dot and dab. He's not doing that in my kitchen again!!
Now the floor is up, we can see that the boards are 22 mm. They are going to put 12 mm plywood over the top of the 22 mm tomorrow. We've noticed that the boards have not been screwed along the joists at 6 inch intervals. I've learnt that from reading the forums. Is that correct?
Thanks for your help.

 

[bugs183]

I and many tilers here wouldn't recommend ply wood, it's not a stable product and doesn't accept adhesive as well as the cement boards i suggested earlier in the thread.
If your planning on using 12mm ply i'd certainly use 12.5mm Marmox cement board. (i'm sure the builder won't agree!).

 

[kaide]

Binsy,
We've just noticed that as well. Our builder demonstrated to my husband that our boarded floor moves. My husband said he wasn't surprised because the carpenter had taken the screws out to inspect the joists earlier today! Of course it would move more without screws wouldn't it. I think I'm getting my sense of humour back again.

 

[kaide]

Hi Bugs183,
Does the self levelling concrete adhere better to the Marmox cement board?
Thanks

 

[bugs183]

oooh it's not self leveling concrete.. it's leveling compound!!!!
Yes everything sticks better to cement board, plywood is an outdated product that people refuse to move on from. It bends, avsorbs water and delaminates. Cement board if stuck down with adhesive and screwed into wood will outperform plywood and it will help your underfloor heating work much better as it will reflect the heat back up into the room.

Now what's this about the floor moving?
If your floor is bouncing or flexing then it needs to be re-enforced, no matter what type or make of flexible adhesive you use.