cracking porcelain kitchen tiles, advice needed

[rosi]

Hi there, we had 60 x 60 cm white polished porcelain tiles laid in our kitchen and hallway 2 yrs ago.Last year a few cracked, this year a few more.The tiles are laid over hardibacker board and 18mm plywood, below that we have water based underfloor heating that was installed on a joisted floor.we were advised that laying the hardibacker board and 18mm ply would be more than sufficient to provide a strong base for the tiles.some of the tiles actually have a kind of smashed crack whilst others a hairline crack. the grout seems to have dried out and is coming out and many of the tiles now move when we walk on them.I cant get our original tiler to return calls so are having to look around for someone experienced to give advice.our hallway is so far ok, its just the kitchen tiles that are cracking....would be very grateful of any advice, also any good tilers in the south side glasgow area?

[GirlRacerRed]

hi rosi

is the joisted floor runing throughout the kitchen and hallway? or is the joisted floor only in the kitchen?

there's a fair few tilers on here from the Glasgow area

[rosi]

yes the whole floor is joisted which takes in hallway leading to the kitchen.

[jay]

sounds like there is a fair bit of deflection in the floor or bounce
does the floor move when walked on

[Del W]

Hello Rosi,welcome to TF.Sorry to hear you have some problems.A number of things may have caused the tiles to fail. Can you post some pictures ? can you lift one of the tiles ? You may have movement in the floor where the joists were not reinforsed or they may have not been fixed correctly using the right adhesive,was the ufh on when the tiles were fixed? If you say what area you are one of the nice chaps on here may be able to have a look.

[rosi]

the tiled hallway is fine and doesnt seem to move- we have 2 small kids with lots of friends who enjoy running up and down it.
in the kitchen- its only where the grout is coming out of some tiles sides that you can feel movement - it feels as if some tiles are no longer stuck to the underneath base rather than the whole floor bouncing.

[jay]

any chance of lifting a tile or piece and taking a picture might help

[rosi]

hi del w, I'll take some pics to post. we're going to try take out one of the cracked tiles tomorrow to see what is underneath and if the adhesive has dried up. cant remember if the ufh was switched on when the tiles were laid...dont think so ! worried that all the tiles are just going to crack and if so what to do? our kitchen was built on top of the tiles so taking all of them out would be impossible, but then retiling on top when the underneath ones are cracking seems pointless - what do you think?

[Del W]

If you had some crack last year and some more recent its going to be an ongoing problem.There is a section on the forum to post a tiler wanted ad on here. You may get away with some replacements but a retile could be on the cards.

[rosi]

thanks, will take some pics of the cracks and what we find when we take a tile up tomorrow and will put out an ad. thanks all for the quick replies.

[GirlRacerRed]

hi rosi

you say in one of the posts above that you can't remember if the UFH had been commissioned before the tiles were laid. this could be a critical point in the installation, and we could do with knowing whether the UFH had been commissioned and working normally before any tiling commenced. commissioning the UFH after the tiles are laid could spell trouble.

[kilty55]

possible dot and dab?

[rosi]

Hi GirlRacerRed, have checked with hubby and the ufh was commissioned/switched on quite a few months (perhaps even 6 months) after the tiling was completed.What problems would that be likely to cause?

[rosi]

Hi Kilty, 'possible dot and dab', do you mean the adhesive could have been dot and dab rather than a complete covering? we are going to try remove one of the most cracked tiles tomorrow and then will be able to see how the adhesive has been applied.

[kilty55]

hi rosi yes,just with you saying tiles are cracking it may be a possibility lets see what you uncover

[GirlRacerRed]

in an ideal world, your UFH should have been commissioned before the area was tiled. were you advised to tile before the UFH was switched on? was the UFH even tested before tiling commenced?

[rosi]

hi girlracerred, no we werent given any advice - neither from the heating installers nor the tiler! the UFH was only commisioned just before we were preparing to move in.why would it have been better for the heating to be switched on before tiling?

[charlie1]

The heating should only have been tested before tiling, not switched on. The tiles should have been laid on ufh while off then tested again for reasons of traceability off fault should anything be wrong with it. Once the floor has been laid, the ufh should be left off for a few weeks, then once switched on should only be incremented a degree at a time over another few weeks.

[rosi]

thanks for the info charlie 1.
I do know that once the tiling was completed, the UFH was commissioned months after and then it was left on very low, around 5 degrees for a week or so before we moved in. then as it was summer the heating wasnt on at all until it got cold in the autumn.

[Gall.B]

sounds like dot dab to me as well, just fixed one today shockingly bad tiles where dabd in 3 places on some on 12mm ply pva & built up 15mm, down less than 3yr!

[GirlRacerRed]

hi girlracerred, no we werent given any advice - neither from the heating installers nor the tiler! the UFH was only commisioned just before we were preparing to move in.why would it have been better for the heating to be switched on before tiling?

my concern here is that if the UFH was not tested before tiling, you wouldn't know if it had any faults/leaks once the tiles were on top. so now you're seeing tiles cracking but you need to check that your UFH system hasn't failed and caused the tiles on top to fail also.

taking the loose tiles up from the floor is the best place to start your investigations.

[rosi]

PIC_1793.jpgPIC_1798.jpgPIC_1792.jpgPIC_1795.jpgPIC_1796.jpgPIC_1794.jpgPIC_1797.jpg

[rosi]

have taken up one tile to see the grout underneath and pics of other cracked tiles and many areas where the grout has just crumbled and is coming out.

[GirlRacerRed]

hi rosi

the picture where you've taken a full tile out, is that a crack running from left to right across the adhesive? do you know if it coincides with any floorboard joints underneath?

[enduro]

Looks like substrate movement, also dosent look much contact on the adhesive on pic 1 to the tile! also looks like a bit of dot & dab in the corners.

[rosi]

hi there, the floor joists run in the opposite direction but it could be a join from the hardibacker board which is underneath (there is also 18mm ply under that.

[rosi]

hi there,yes the adhesive is untouched apart from the 4 corners where it looks like extra was added to level the tile,but not sure why it was done like that!what is substrate movement?

[jay]

Hi Rosi the pics dont paint a pretty picture
as mentioned above the crack running through floor after tile was removed indicates either movement in sub floor or poor prep work before tiling
if you look at the glue application on the floor its been spread (sort of) and it looks like spots of adhesive have been added to lift tile height ,leaving the center of the tile unsupported causing the tile to fail (its another form of spot fixing) recommend you try to get original tiler back or if you like we may have a member in your area who may take a look for you
good luck
PIC_1792.jpg

oh and thanks for the pics


is the adh hard like cement or is it like rubber

[rosi]

thanks Jay, I'll try again to get hold of our original tiler again, however i would be grateful if there was a tiler in the G77 area of glasgow who could come and have a look.not sure if I need to place an ad on this forum or how to do it or if its ok to just say on this message board?

[enduro]

Just say on here thats fine, and im sure there is a tiler on here that will take a look and advise what to do.