Help me with repeatedly floor cracked tiles PLEASE - Tile Advice

[tubelloabril]

Hello! Please I need your help. I'm living in a 3yo department on a 5th floor (the entire building is 14floors). 3 months after moving in I noticed hairline cracks on more than 10 floor tiles, some of them linear and comprising 3/4 adjacents tiles. Others, just randomly on one isolated tile. I had them replaced, but a year later discovered the same problem: many of the repaired tiles had THE EXACT SAME CRACK in the exact same place (linear, including 3/5 adjacents tiles). Had them replaced again and now, after 6 months of the last replacement, I found that same linear hairline crack is appearing on THE SAME REPLACED TILES and following the same direction. Cracks are almost imperceptible (just able to see the if I bright a light on them). But I'm very concerned. The builder company says it's normal for a big building to move and to have some cracks but I'm super worried. Why is it that they happen to be always in the same place/tile and following the same direction? May this indicate a structural problem?

I would really apreciate your help. Try to attach some pictures. Thank you in advance

 

[Nathan Walker]

Tiler most probably hasn't prepared the floor correctly, an uncoupling sheet/crack mat should have been installed to prevent cracks forming due to movement of the floor. In my opinion needs ripping out and starting again from fresh.

 

[Cookson&Co Tiling]

Tiler has most probably not used an uncoupling sheet/crack mat when preparing the floor for tiling, this prevents cracks forming from movement and settling of the floor over time. Please see attached photo of said matting.

 

[Dave]

Hello! Please I need your help. I'm living in a 3yo department on a 5th floor (the entire building is 14floors). 3 months after moving in I noticed hairline cracks on more than 10 floor tiles, some of them linear and comprising 3/4 adjacents tiles. Others, just randomly on one isolated tile. I had them replaced, but a year later discovered the same problem: many of the repaired tiles had THE EXACT SAME CRACK in the exact same place (linear, including 3/5 adjacents tiles). Had them replaced again and now, after 6 months of the last replacement, I found that same linear hairline crack is appearing on THE SAME REPLACED TILES and following the same direction. Cracks are almost imperceptible (just able to see the if I bright a light on them). But I'm very concerned. The builder company says it's normal for a big building to move and to have some cracks but I'm super worried. Why is it that they happen to be always in the same place/tile and following the same direction? May this indicate a structural problem?

I would really apreciate your help. Try to attach some pictures. Thank you in advance

What is the subfloor constructed from ?

 

[tubelloabril]

What is the subfloor constructed from ?

Sorry. By subfloor you mean the slab below the tiles? It's a concrete slab (entire building made up with concrete)

 

[tubelloabril]

Tiler has most probably not used an uncoupling sheet/crack mat when preparing the floor for tiling, this prevents cracks forming from movement and settling of the floor over time. Please see attached photo of said matting.

Thanks! They haven't used this mat. But why is it that cracks keep appearing on the right exact place following the same path?

 

[Dave]

Sorry. By subfloor you mean the slab below the tiles? It's a concrete slab (entire building made up with concrete)

The slab could have cracks in it and these wilm transfer through the tiles with with expansion. Looks like a re-tile if so.

 

[tubelloabril]

The slab could have cracks in it and these wilm transfer through the tiles with with expansion. Looks like a re-tile if so.

Thanks. But it's not normal for a slab to have cracks... Is it?
Is this an structural problem? I'm super worried

 

[tubelloabril]

Tiler most probably hasn't prepared the floor correctly, an uncoupling sheet/crack mat should have been installed to prevent cracks forming due to movement of the floor. In my opinion needs ripping out and starting again from fresh.

Thank you! They didn't use any mat. But appart from the cracks do you think it could be an structural problem? As they keep appearing on the right exact place...

 

[Dave]

Thanks. But it's not normal for a slab to have cracks... Is it?
Is this an structural problem? I'm super worried

Yes they can crack and not normally an issue but can transfer to the tiles.

 

[tubelloabril]

Yes they can crack and not normally an issue but can transfer to the tiles.

But I mean it's usual for a slab to crack or means that there is something wrong with it?

 

[Dave]

But I mean it's usual for a slab to crack or means that there is something wrong with it?

Yes they can crack during curing. We are purely guessing till you see what’s underneath

 

[tubelloabril]

Tiler most probably hasn't prepared the floor correctly, an uncoupling sheet/crack mat should have been installed to prevent cracks forming due to movement of the floor. In my opinion needs ripping out and starting again from fresh.

Thanks! But why is it that they keep appearing on the right exact place again and again?

 

[Johnno]

You should expect any building to expand & contract with changes in temperature and humidity .think of it as a living entity..it has to breathe to survive..it it didnt it would eventually fail..these contractions and expansions are minute but happen in all structures no matter what they are made from.
Has a flexible floor adhesive and grout been used to secure your tiles ?
Although I have never suffered this problem after an install I have had grout break out due to excessive movement of the sub floor..next time your tiles are replaced ensure a ' super flex ' adhesive is used and possibly a flexible ad mix to boost the flexibility of the adhesive..the install I had problems with I used both, a super flex tile adhesive ( powder so you can mix it yourself & add the flex additive ) and same for the grout. This route solved the issue I had and hopefully will resolve those you are having

 

[Johnno]

a building has to breathe..by that I mean expand and contract as the temperature and humidity changes , any movement is only minute but they are built to do just that..they would simply fall apart if they didnt...I would suggest the sub floor below the tiles cracking is prob flexing moving slightly more than elsewhere and the tiles are fixed too firmly across that area so cracking.
Ensure a ' super flexible ' adhesive is used next time they are replaced. You could also add a flexible additive to give it extra flex ( make sure it's a powder mix not ready mixed out of a tub ) then you can use the additive to provide that extra bit of flexibility.
I've only ever had problems with grout breakup g out due to subfloor movement and although used a flexible grout , the sub floor movement was still too much so when re grouting used some additive..problem solved..you will probably find that your installer have not used a flexible adhesive because your sub floor is a concrete slab and unlike a timber sub floor , you dont expect it to flex / move in any way, whereas a timber sub floor can move / flex quite a bit..
Hope this helps