Bathroom floor tiling and laminate flooring problems

[SOTV]

Just moved into a house which has underfloor electric heating in the bathroom. Problem is that the black grouting around the large flooring tiles is coming away leaving black bits of grout all over the place.
Assume grouting is being dried out by the heating. Any ideas on how to stop the grouting coming away?
Also we now have inherited laminate flooring all over the groundfloor. The problem is that it creaks all over the place when it is walked upon and appears to be flexing/bending in parts!! Any ideas on how to solve this without it all up being ripped up and started again?
Thks in advance

 

[WoodYouLike]

Has the house been empty for a longer time without heating?
Could be that the floor has expanded for that reason.
If not and it's possible, remove some of the beading or skirting which covers the expansion gap (should cover I must say, could be that it wasn't taken into consideration) to see if this still exists.
You'll have to 'free-up' the floor then by cutting some of the width off.

 

[Mudster]

Re the floor tiling you have the following possible problems:-

1/ The substrate has not been prepared correctly and the tiles are moving, the cracking grout is due to localised movement.

2/ The wrong adhesives and grout have been used (non flexible).

3/ Both of the above

It's highly unlikely that the fault will actually be anything to do with the underfloor heating.

Unfortunately there is no quick fix, the solution is pull it up and do it all correctly.