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Why are we having so many problems with our polished porcelain tiles?

We had our kitchen refurbed and found some lovely polished porcelain tiles. As the kitchen diner is now 30 square metres with large windows/bi-folding doors we decided to have underfloor heating. We were advised to get the floorboards secured, lay a backer board which had to be secured at regular intervals with drywall screws. The underfloor heating was laid (warm touch wire) Then a latex screed was laid and the tiles laid on top of this. Within 2 weeks the tiles started to make a noise when we walked over 2-3 of them. The tiler came back, dug out the grout and injected more adhesive. This helped but not for very long.

The underfloor heating was very patchy as well quite warm in some places but quite chilly in others. After nearly 4 months we got the tiler back. He lifted 3 tiles and showed us how much the 'sub-floor' was moving. It was very noticeable. The tiler also told us that the builders continued to walk over the floor whilst he laid it. Even moving an washing machine. Plus he said that he had to use much more adhesive in some areas than others. Why would that be?

We contacted the builder who is trying to blame the underfloor heating for 'drying out' the floorboards and does not want to play the 'blame game'. We have been advised that the builder should have checked the floor joists Is this correct? As these may be moving. Also we have been advised that the underfloor heating should not have been turned on for a week and that the latex screed should have been left to dry for 3-4 days. Is this correct? Also we have been asked if the tiler used a flexible porcelain adhesive. We have no idea as we are not tilers! Can this be checked if we get the tiles up again? The three tiles that were taken up came up without breaking, everyone is saying that the wrong adhesive must have been used as they should come up that easy.

Can anyone answer these questions please? It cost us a small fortune to have this done and we have been left with a noisy, sub standard floor which is not remotely warm in places. Who is to blame and should the builder/tiler put it right at no cost to ourselves?

3 Answers from MyBuilder Tilers

Best Answer


Yes the builder should of checked the joists and been aware that timber floors move/shrink and advised against them in the first place....The tiler shouldn't of laid tiles on that subfloor, if it was obviously moving. Using more adhesive in certain places is because the subfloor isn't flat/level enough.

It would of been better to have taken the oringnal floor boards up and binned them, laid 25mm wbp ply instead, with noggings at the joints. Your joists would probably need strengthening first, with either extra joists or noggings etc to stiffen the floor up first.

The whole floor sounds a bit bodged, and underfloor heating doesn't sound like it was installed properly, if you have hot and cold spots. This could well be down to the thickness of adhesive in places.

You need to allow the manufacturers drying times, for latex, tile adheasive and grout before turning the under floor heating on. This could be why the tiles are lifting easily now.

It sounds like a careless rushed job...

They are both to blame though, they both should put it right for free.


Answered 31st Dec 2011

Hi i agree in principle to the last 2 comments, as a tiler i would always check the sub floor prior to installing the tiles. With modern tile adhesives you can tile direct to floor boards using a 2 part adhesive (Bag & a Bottle) but the floor boards must be in perfect condition and screwed to joists, in most cases i have always over boarded in 10 - 15 mm ply as reccomended by the adhesive manufacturer, if there are problems with levels on the floor a flexible floor leveler should be used.
When you lifted the tiles the adhesive should have covered all the tile, some bodgers dab the tiles to overcome differences in floor levels, if this is the case then i'm sorry but the floor will need to come up, this would also explain warm and cold spots as the under floor heating wire will be warming air and not the tile.
I hope this helps


Answered 4th Jan 2012

Hi this is hard to say who is to blame it seems to me that there is a lot of movement,with the combined weight of tiles ,adhesive and board it could be the floor joist are not man enough to take the weight,I would also say no good tiler in his right mind would let anybody walk over his work until he had finnished have you ask the tiler what adhesive he used ? its hard to say how long you would leave the floor to dry as it depends on the conditions,was the floor primed before the latex was done? and yes you can use more adhesive were the floor is uneven but this should not make a difference.if the tiles are coming loose did the tiler use the right trowel for the job it sounds like there was not much coverage on the tiles as some tiles need to have the backs buttered as well as the floor with adhesive.I think you need to get as much information from both trades as to what they had done,was there any written estimate stating anything about the work to be carried out,as for the underfloor heating you could have a damaged cable,me personally i think underfloor heating is more trouble than its worth,.If you can find out the name of the adhesive used then you can call there technical department they can advise and even send someone out .I hope this helps .


Answered 31st Dec 2011

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