Tiles lifting after 4 years - what's gone wrong?

[GaryW]

Hi Folks,

Hoping someone can offer some explanations for my issue here:

Moved into a newbuild house 4 yrs ago, tiled the kitchen with 25 sqM of porcelain tiles, used Bal rapidset adhesive on a 20mm bed, grouted with Bal wide joint flexible - subfloor is concrete pad overlaid with screed. Lovely job, missus well impressed, loads of brownie points.

January this year we completed a build of a sunroom on the back of the kitchen that removed part of a supporting wall, since then some of the previously solid tiles have started to lift. There is no water ingress, no leaks anywhere and the sunroom although attached to the house does not form part of the original foundations/subfloor.

The tiles that are lifting are bossed (hollow sounding when tapped and exhibit some signs of movement) althought the grout is not cracked (the joys of flexible grout?)

What I need to know is why would they start to lift?, my insurance company aren't being particularly helpful; suggesting that I need to determine what has caused the breakdown and whether the cause is covered under the policy before they'll consider paying for replacement/repair.

Cheers
Gaz

 

[david campbell]

the hollow tapping sound is usually a sign of dot and dabbing or voids were the adheasive shoul be,but as you done this your self i'm assuming there is full coverage underneath the tile!

 

[jay]

hi sounds like expansion probs have you allowed for movement:8:

 

[GaryW]

Thanks David, there was a couple that did sound hollow afterwards - and I realised that that would have been the cause (they were in the wee cuts next to the kickboard of the base units) but the majority were all solid. I sat in the sunroom the other night and heard crackling (like a handfull of pebbles being thrown on a tiled roof) and went into the kitchen to see what it was - turned out it was a load of new tiles lifted. Could it be that somehow water has got in beneath when the floor has been mopped?

 

[GaryW]

Thanks Jay, allowed 8-10 mm all round so that it was covered by the skirting - was that enough?

 

[jay]

yes that should br fine as long as its still open (free to move did you Silicon) also whats your longest span length of tiles:8:

 

[david campbell]

if the floor has been mopped every day for the last 4 years then there is a good chance that the water has progressively moved under the tiles causing them to come loose,it wouldn't ahve happened though if it was completely grouted and siliconed round the perimeter!

 

[GaryW]

Didn't Silicon the edges, longest span is just over 5m, but it's only two tiles wide (600 mm ish) - still can't work out why it would start to lift after 4 years though, if it wasn't properly bonded wouldn't it have shown signs before now?

 

[jay]

:8:were are tiles lifting can you explain middle edge ect

 

[GaryW]

It seems a though the areas that are affected most are the main routes through the kitchen, the utility room and wee cupboard under the stairs are all sound. Where they have started to lift (sound hollow/crunchy) the tiles around them which previously were solid have started to do the same, on one particular section if I stand on it there's a definite squeek/whistle which is (I think) air being pushed out from underneath. I need to explain the cause before I can claim on the insurance - but it's got me baffled a friend who is a builder suggested it may be settlement in the subfloor but proving that will be a nightmare.

Appreciate all the feedback/suggestions by the way!