cracking grout

[Unregistered]

Greetings tiling people
I have recently had my bathroom tiled - wall and floor. The grout in between the floor tiles is now cracking and coming out in a few places. The tiles were layed onto 12mm marine plywood which was screwed through the floorboards into the joists (obviously not very well). There is some creaking when we walk in the bathroom and in one place a certain tile makes a noise every time it's stepped on. The grout used was mapei and the adhesive was Porcel flex rapid.
I have no chance of taking up the tiles and having it redone so could someone in the know please answer these questions for me..........
A builder I know told me to take out the grout and use mapei coloured silcone instead. Other people who I have mentioned this to have told me it's a very bad idea!
Secondly - I have been told that I can regrout the tiles but to use an additive to make the grout more flexible to stop it cracking again. This sounds a bit more feasible to me. Would this idea work? If so, whats the additive called.
Thanks for any replies.
Daniel

 

[Gazzer]

Sorry but your builder is clown !
If the floor is squeaking then there is movement and that will crack the grout and in time the tile.
You could try regrouting, it may or may not work, hard to say with out knowing how much the floor is moving. The most flexible grout I have used was Bal with their GT1 admix.

 

[AliGage]

You say there is some creaking when you wall on the floor? Yet the boards were screwed through to the joists. Could be that a join in the ply wasn't made over the Joists or supported by noggins in anyway.
A creak and a crack certainly doesn't say the floor was prepared properly and still has deflection. I don't think any amount of additive is going to solve your problems because if the boards are moving then eventually they will delaminate from the floor.
Have you contacted your builder? What has he said? Im afraid this sounds like another rip out and start again job to me :banghead:

 

[Stef]

That floor needs to come up & relaid
There is no easy quick fix.

 

[johnryan]

sound like you have several problems compounding the issue there. ply to thin, no backerboards. not screwed down firmly enough. could only see it getting worse, and would say there's no quick fix for it. i think you need to speak to your tiler again.

 

[Unregistered]

Thanks for all the replies. I do understand that the floor needs to come up but unfortunately this is not an option.
As there is only 1 tile that is making a slight noise when stepped on would it be possible to replace just that 1 tile?
What about regrouting everything but using an additive to make it more flexible?
I am in the dilemma of having to rectify the problem but not being able to take the floor up.
Thanks again for all replies.
Daniel

 

[Ian]

You'll probably find that the offending tile has debonded from the floor, that's what's causing the grout to crack (as well as the movement in the floor). In time I'd say more tiles will do the same. Remove the offending tile and see what is underneath, some pics would really help once you have done this.

 

[DHTiling]

We can only tell you how it should be done and not offer a bodge fix... you cannot make a pedigree out of a mongrel .

 

[Ajax123]

Thanks for all the replies. I do understand that the floor needs to come up but unfortunately this is not an option.
As there is only 1 tile that is making a slight noise when stepped on would it be possible to replace just that 1 tile?
What about regrouting everything but using an additive to make it more flexible?
I am in the dilemma of having to rectify the problem but not being able to take the floor up.
Thanks again for all replies.
Daniel

why can you not have the offending someone take up the floor that the offending someone as incorrectly laid and have them re lay correctly... Doesn't make sense. It's only going to get worse. 1 tile has faied already, your grout has cracked and pulverised, you have subfloor movement...it's on the wrong grade of ply....is this a job that you have done and need some help/advice to fix it....

 

[bugs183]

As everyone above says this floor is on it's way to failure.
Grout is only there to fill the gaps i between the tiles, it has no structural value, it's the adhesive and its bond to the floor beneath it that is the strength in the floor. No amount of grout no matter how flexible will solve this problem. Yes you can take up the loose tile, but if the floor is squeaking then it is moving and will fail again.
The builder has given you totally incorrect advise, it wouldn't work and it would look awful.
As Ajax says, if you've had your bathroom tiled, get the numpty back to fix it. Bottom line is it's not been laid properly.