Why have the tiles cracked? - Tile Advice

[xxglasglowxx]

Hi all, I posted on here about a year ago as we had a lot of problems with newly fitted bathrooms. We hoped our troubles were (mostly) behind us however a year on and the floor tiles have cracked. Could anyone offer any thoughts as to why they are cracking? I will attach photos....the crack runs across about 4 tiles.

 

[Dave]

Hi all, I posted on here about a year ago as we had a lot of problems with newly fitted bathrooms. We hoped our troubles were (mostly) behind us however a year on and the floor tiles have cracked. Could anyone offer any thoughts as to why they are cracking? I will attach photos....the crack runs across about 4 tiles.

Hi. Looks line stress/deflection cracking. What substrate is it. ?

 

[xxglasglowxx]

Hi. Looks line stress/deflection cracking. What substrate is it. ?

Hi. Looks line stress/deflection cracking. What substrate is it. ?

I believe it’s just plywood. There is (very badly installed) underfloor heating too) What is deflection cracking?

 

[Dave]

When the floor moves up and down too much resulting in tile cracking and could be insufficient adhesive under the tiles.

 

[xxglasglowxx]

When the floor moves up and down too much resulting in tile cracking and could be insufficient adhesive under the tiles.

Thank you. In your opinion would this be due to poor workmanship?

 

[Dave]

Thank you. In your opinion would this be due to poor workmanship?

Quite possibly but until you see what’s causing the issue you can only surmise .

 

[xxglasglowxx]

Quite possibly but until you see what’s causing the issue you can only surmise .

So if a tile was lifted do you think the cause would be visible? And do you think this issue will worsen if left alone?

 

[Dave]

So if a tile was lifted do you think the cause would be visible? And do you think this issue will worsen if left alone?

Yes it should be visible and as for getting worse . Depends on what’s happened

 

[xxglasglowxx]

Yes it should be visible and as for getting worse . Depends on what’s happened

That makes sense. Thank you for your replies.

 

[2001Steve]

Substrate problem. If your floor is wooden floorboards I wouldn't tile the floor unless it's been cross lined with not less than 10mm ply screwed (not nailed) down with screws every 15cm minimum. Boards beneath need to be thoroughly fixed on the rafters too. Anything less the adhesive will crumble away due to deflection issues (as above) and the tiles will crack. In short...wood is flexible and tiles are not so you need to make the wood thick and strong to stop the bending. This will make your bathroom floor 20 to 25mm higher than the board level and many people don't like that.

 

[Dave]

Substrate problem. If your floor is wooden floorboards I wouldn't tile the floor unless it's been cross lined with not less than 10mm ply screwed (not nailed) down with screws every 15cm minimum. Boards beneath need to be thoroughly fixed on the rafters too. Anything less the adhesive will crumble away due to deflection issues (as above) and the tiles will crack. In short...wood is flexible and tiles are not so you need to make the wood thick and strong to stop the bending. This will make your bathroom floor 20 to 25mm higher than the board level and many people don't like that.

Morning steve. It’s now not advisable to tile too plywood now , a change to bs5385 around 3 yrs ago i think now. Too much inferior Chinese plywood lol.

 

[benchwarmer]

Substrate problem. If your floor is wooden floorboards I wouldn't tile the floor unless it's been cross lined with not less than 10mm ply screwed (not nailed) down with screws every 15cm minimum. Boards beneath need to be thoroughly fixed on the rafters too. Anything less the adhesive will crumble away due to deflection issues (as above) and the tiles will crack. In short...wood is flexible and tiles are not so you need to make the wood thick and strong to stop the bending. This will make your bathroom floor 20 to 25mm higher than the board level and many people don't like that.

10 mm ply will still expand and contract,as you've just said "wood is flexible" so why cover it with more wood? Wow!!! It's not all flexibility, it's expansion and contraction, that's why tilers don't use it! This guys floor is completely nackered because of substandard multi traders following substandard advice, and the argument of "well I've never had a problem “is mainly due to the fact that people will not allow monkeys back into their homes and would rather go elsewhere. Please stop posting now before you ruin any more homes mate 👍🏻and leave the tiling to the tilers.

 

[Jon_Hall]

Morning steve. It’s now not advisable to tile too plywood now , a change to bs5385 around 3 yrs ago i think now. Too much inferior Chinese plywood lol.

Hi Dave the part of BS5385 you're referring to is, that plywood not recognised as suitable substrate for wall tiling, hopefully it will be the same for floors too, in the not to distant future. However I totally agree that there are far better options for suspended floors, that are more rigid and not subject to thermal movement.

 

[Dave]

Hi Dave the part of BS5385 you're referring to is, that plywood not recognised as suitable substrate for wall tiling, hopefully it will be the same for floors too, in the not to distant future. However I totally agree that there are far better options for suspended floors, that are more rigid and not subject to thermal movement.

I haven’t used ply for many many years Jon. Too much to go wrong. Did think it included floors lol. But must admit it should include both.