Floor Crack Help

[markmcd]

Hi,

We have just had a tiled floor installed with underfloor heating by a firm fitting our bathroom. Floor has been down just over a week and a hairline crack has already appeared in the grouting running from the door all the way to the opposite end of the room. That is along 8 tiles i.e. approx 8 feet long. Floor seemed to be prepped OK at the time i.e. boards were nailed down before underfloor heating was layed, followed by tiles on top (had lino before).

What do you people advise - installation of bathroom is not complete but should we be asking for the entire lot to be lifted and re-layed? Any ideas as to why this has happened? I assume the crack is through the entire depth of the floor too and that simply splashing some grout over it is a no-no as the crack will just reappear?

Any help and advice appreciated.

Mark

 

[mattysupra]

tiles was installed direct on top of floorboards or over boarded with plywood first? Or floorboards uplifted and a thick plywood installed?

 

[markmcd]

hi,

plywood was first nailed down to the existing floorboards i believe.

thanks

 

[Symptoms]

mark - check at the doorway to see if you can see what layers (and their thickness) there are below the tiles. This might help answer mattysupra's questions. You think there was ply NAILED (not screwed???) to existing floorboards; how thick was this ply; what type of ply (exterior grade -WBP? - this won't cause the movement but should be fitted). Were the existing floorboards fixed down correctly to prevent them moving and thus providing an unstable base for the ply?

The fact you have a long straight 8' crack in the grout suggests that the join between 2 adjacent sheets of ply (the sheets are 8' long ... a bit of a coincidence!!!) is moving ... movement causes cracks and ALWAYS WILL. A temp repair to the grout will not work.

Have you paid them yet?