Help!: Porcelain floor tiles coming loose

[Gul]

Hi, I have just joined the forum and am looking for some info. I have bought & had laid (about 3 months ago), some cream B&Q 600 x 600 porcelain tiles. I must admit they looked pretty good. However, I have now noticed that some of the tiles are loose at the corners. When I tap the tiles they are fim in the centre, but a few sound loose at the corners.

I used a very reputable tiler, who came highly recommended, the products he has used, I'm told are high quality. I went back to the supplier and they have contacted their technical people who are saying that the adhesives should be ok

Any idea what this might be ?

[GirlRacerRed]

you need to get the Tiler back in to have a look. with big format tiles like that you need a solid bed adhesive to ensure full coverage on the back. if they're sounding hollow around the edges, you need to ask the tiler how he fixed them. you can find out how deep the adhesive bed was by asking him what size trowel he used.

[Gul]

He's coming round this evening, do you know of any problems like this being attributed to anything specific? I've heard some stuff on wax coatings etc.

[GirlRacerRed]

You need to find out how he fixed them first. It might not be the tiles that are the problem. It could be the fixing method, it could be problems with the adhesive. You need to get your tiler to help you find the source of the problem and then we'll be able to find a way to help you rectify it.

have any of the tiles actually come loose yet or are they just sounding hollow?

[Gul]

Just sounding hollow at the corners ....

[GirlRacerRed]

do you know what adhesive was used?

[Gul]

One thing I've had mentioned is the joint size, the tiler used 2mm joints with underfloor heating, is this an issue ?

[GirlRacerRed]

One thing I've had mentioned is the joint size, the tiler used 2mm joints with underflor heating, is this an issue ?

on a floor the Britist Standard recommendation is 3mm grout lines. 2mm and you're pushing it a bit.

how soon after laying the floor was the underfloor heating commissioned and working?

[Gul]

Mapei, Keraquick S1 rapid set adhesive

[GirlRacerRed]

Mapei, Keraquick S1 rapid set adhesive

and exactly what kind of floor substrate were the tiles being laid on? concrete? floorboards? chipboard?

[Gul]

The underfloor heating was working before the tiling was carried out. It had been on, I can't remember whether the tiler had it on or off when he was tiling, off I think.

How critical is joint size, would restricted movement cause the issue?

[Gul]

concrete floor, big area, circa 50 m2

[GirlRacerRed]

I can't say for definite whether the 2mm grout line would restrict the porcelain in anyway, because I'm not a professional tiler. I'm sure plenty of our pro members will be along shortly to give their views.

as for the concrete floor, was it all one area or was it part of a bigger building project perhaps where 2 different rooms became one?

also, are the hollow sounding tiles in any particular place? round the edges of the room, in the centre, near door frames?

[Gul]

The whole floor was laid from scratch. The loose tiles are pretty much distributed throughout the entire floor, no descreet area.

[Gul]

I guess I'm going to have to get a couple up with the tiler and see exactly what has happened.

[GirlRacerRed]

I guess I'm going to have to get a couple up with the tiler and see exactly what has happened.

to be honest, if they only sound hollow and are not loose, then getting one or two up is the best way forward. if they had already come loose and detached from the floor, this would make your life easier.

for months after laying my kitchen floor i was paranoid that I could hear hollowness below the tiles. but after nearly 2 years, they're still stuck fast.

to the best forum in the world by the way

[Gul]

Thanks for the help.

[paul flight]

did your tiler tell you to leave the floor heating of for up to 10 / 14 days after the tiling was completed??

[grumpygrouter]

Personally, I think that 2mm for tiles onto UFH is too small, especially large format tiles. The grout joint is there to take up expension in the tiled surface and you have not got much leeway with a 2mm joint. I don't think this is the issue though with repect to your query, sounds more like a fixing issue of some sort. Keraquick is fine for that type of installation so I don't think that is the problem either.

[david campbell]

it sounds as if the floor was dusty and the adhesive has not bonded with the floor,or they tiles were not back buttered and forced into place properly!

is the adhesive stuck to the back of the tiles or floor when they have came loose

[GirlRacerRed]

dc, they're not loose, yet. Gul has just tapped a few and they sound hollow. I guess we'll have to wait and see what his tiler says.

[david campbell]

dc, they're not loose, yet. Gul has just tapped a few and they sound hollow. I guess we'll have to wait and see what his tiler says.

slightly mis-red!

did the tiler spread the adhesive on th floor or each tile individually?

[mikethetile]

could be dot and dabbed

[Scott]

Thats a large area and no room for expansion with a 2mm joint. Did he use a flexible grout?

[andy-p]

A decoupling mat should have been fitted ...

[Gul]

The tiler has come round to take a look. Interestingly the bulk of the tile appears to be firm, just the corners on a few and a few abutting corners. Looks like to adhesive has set firm to the concrete floor but not too well to the tile. The tile I have looked at is pretty clean, so we're a bit puzzled.

My tiler suggests that we clean out the grout of the loose coner and force adhesive or grout down as a first option, to see if we can secure the loose corner.

Anything has got to be worth a try. MY worry is whether the secured tiles eventually come loose.

Do you think that if they are stuck now, there's no reason to think they will come loose later ?

[Gul]

what's a decoupling mat ?

[Gul]

Adhesive was combed on with a serated trowel. The tiler has used expansion joints using a mastic, every 3 metres.

[Dave]

Is the adhesive still in a combed effect on the floor or totally flat under the tiles.?

[andy-p]

what's a decoupling mat ?

This is the decoupling mat i use and this is a quote from their tech.



PCI Pecilastic is a separation layer suitable for use under ceramic and natural stone tiles. It is suitable for indoor and outdoor use on all sound and cracked substrates and for use with underfloor heating systems. The PCI Pecilastic layer enables the substrate beneath to move laterally which means the tile above is protected from the detrimental affects, which sub floor movement, can cause. A solid bed can also be achieved due to the flat nature of the membrane eliminating the problems associated with point loading as long as the appropriate tile is selected.