Grout coming out and crackling noise under some tiles

[Andy Allen]

Yeah I know!

So how do you know it's not a bond problem due to not back skimming?
Also by the second time it was tiled I imagine the floor was drying for more than 3 weeks..... Plus with the heating being turned on it would force dry the floor......
Still could be wet though... Lol
Need to lift a tile really.....

 

[Flintstone]

I’ve known of screeds still being wet after 8 months even with ufh!
I would be very supprised if the tiles came up clean with the adhesive stuck to the floor, after all the failed anhydrite floors I’ve seen personally and online, always come up leaving the floor clean.

 

[Sachin Parab]

Hi Andy,

To answer your initial question yes he did put adhesive on the floor using a notched trowel but not sure about dabs at the back of the tile as I didnt see him do that.

 

[Sachin Parab]

Hi Localtiler,

Thanks for your input into this. As Andy has mentioned the screed has been left to upto 7 weeks to dry considering it was tiled the second time. The hygrometer reading was within normal limits (cant remember the exact readings, but I was there when the readings were taken). He took the reading from different areas downstairs.

When we lifted the tile the first time (when about 90% of the tiles were actually moving), the adhesive was stuck to the tile not the floor. Hence after discussion with technical team at Mapei the primer was used.

This time around about 15-17 tiles of the total 180 odd tiles are showing signs of grout loosing and crackling sound is being heard under 3-4 of them.

I am unsure why this should be happening if it was a bonding issue with the anhydrite. I would have expected all of them to have started moving by now. May be it will happen in due course I am not sure, but the first time it happened in a matter of a few days of turning the UFH on.

 

[Qwerty]

Got any photos with close ups?

 

[Flintstone]

Best option here is to remove a tile and post a photo, if possible

 

[Rookery]

Bl@@dy anhydrite screeds

 

[Tile seller]

I had a situation recently where the screed hadn't been abraded well enough or the ensuing dust hadn't been hovered up causing a tanking membrane let go. White dust was all over the back of said membrane.
This customer just used a hand held sander to abrade and I believe that something more substantial is required.
I wonder how this screed was abraded.

 

[Andy Allen]

Not trying to be funny.... But are you sure your builder was qualified enough to prepare such a specialist screed ?
The fact it failed the first time due to some very basic errors wouldn't be giving me much confidence he's up to the job.
Unless these screeds are prepared absolutely spot on then they will fail, and saying the grout is cracking due to it not being pushed in enough to fill voids is absolutely ridiculous....... There shouldn't be any voids in the first place.

 

[Old Mod]

Removing laitence from the floor is not just a case of a quick skim over or using a scrapper.
What method did he use and what equipment?
This year I ripped out and refixed an anhydride floor, which I know 100% was sanded by the contractor.
The reason I know is the client made a point of asking what they were doing.
The Builder then continued to install the floor with his Tiler.
9 months later it failed, on inspection, laitence was still present, it failed.
So we had to start from scratch, including re sanding of the floor.

The moisture reading using the hygrometer, how long were they left in place before readings taken?

 

[Dave]

80 sqr mtrs ?
Where any expansion joints used ?

 

[Sachin Parab]

80 sqr mtrs ?
Where any expansion joints used ?

No none were used, that was my other query to the builder. Is there any way this can be added now.

 

[Sachin Parab]

Thanks all for all your input.

Is there any remedy through this which will avoid taking tiles off the third time as all my stuff is in or the best way would be to repeat the same again with suggested procedures.

 

[Dave]

No none were used, that was my other query to the builder. Is there any way this can be added now.

What is your biggest area , too large an area without expansion can cause delamination.
Just another thought on your issue.

As mentioned , you need to lift a tile and see whats going on underneath.

Are any expansion joints in the screed ? Ie doorways etc ?

 

[Sachin Parab]

The largest area is around 20 square meter. No expansion joints on the doorway or any other areas