mapei build fix flexible wall & floor grout

[Debbie22]

Hi all I am wondering if anyone can help?
my husband who is not a tiler but gets by grouted our wet room about 2 weeks ago we used the above product with the liquid unibond flexi mix additive a week later our shower began to leak where we realised cracks had appeared between a lot of the joints, we have scrapped all loose grout away but haven't removed all the grout as have underfloor heating, can anyone tell us if it's ok to grout over already grouted areas or do we need to remove all the grout in which case is there an easier way without damaging underfloor hearing many thanks a complete novice, Debbie

 

[bugs183]

Hi Debbie.
I'm afraid to say i doubt that the grout is to blame here, it sounds like something a bit more serious is going wrong here
It sounds like something is moving under the tiles and no amount of regrouting will stop this.
We'll need lots of answers here to try to help.
Is it the walls or floor that is cracking?
What are the walls and floors built from?
What kind of wet room is it, and what was used to tank the room?
If wood on the floor, was there any movement?
How was the under floor heating fixed?
Did you use self levelling over the heating?
What are the tiles, ceramic, stone or porcelain?
What adhesives did you use? Did your hubby use a notched trowel or just dab the tiles?
Photo's will be useful.

 

[Debbie22]

oh no ok I'll answer what I can
it's the floor esp around shower and a small area in front of bath! as far as I am aware there is floor boards cement boards under floor heating then tiles the floor tiles are large and were dabbed.
the adhesive was keraquick rapid set. I'll try and attach photo

we are thinking we may have used heating to soon??

 

[bugs183]

Thanks for that.
I'd say it's the fact that the tiles were dabbed that has caused the problem, thats for starters.
How were the cement boards fixed to the floor? After the underfloor heating was laid on the cement boards, did your hubby self level over these or dab straight over the mat and the boards.
How long was it before you used the underfloor heating?

It appears that this floor is beginning to fail. At the very least the floor tiles themselves will debond or crack because the method of dabbing is no good for fixing floor tiles as you need 100% adhesion under the tiles as they are taking lots of weight loading from foot traffic.
If you havn't levelled over the under floor heating it could burn out because of having hot spots where there is no adhesive.
Sorry to give you the bad news Debbie.

 

[Debbie22]

Hi thanks for your reply, Its not looking to good, I have since spoken to my husband and he laid half the floor after our friend (joiner) laid the tiles in shower area and set drain he covered entire tile with adhesive and our friend spread cement dirctly onto floor and also dabbed them so not sure if that changes it slightly?
the uf heating was used after 48 hours so not sure if this may be problem.
I appreciate it maybe easier for you with photos but every time i upload it comes up error ??
We have scrapped away the grout from the areas where cracks had appeared to re-grout and when we apply pressure to the corners we can see slight movement but not sure if this is because there is gaps between them now?
What would next step be? the areas are not big so.... should we patch up and see if cracks again or get a tiler in (he will probably run a mile
Many thanks, Debbie

 

[White Room]

Ufh should have been left for at least 2 weeks....I would get yourselves a good tiler, this is'nt a patch up job.. http://www.tilersforums.com/im-looking-wall-floor-tiler/

 

[Debbie22]

ok many thanks for everyones help

 

[bugs183]

Yea as above, if there's the slightest hint of movement then the grout will crack, the floor really needs retilng.