Would you consider this quality work?

[One Day]

if the tiles were brought in from the cold, that could affect the bond too.
Bad batch of adhesive - not enough polymer to bond to the porcelain?

 

[Spud]

Was the floor checked with a hygrometer before the adhesive was laid , and do you have evidence of the results ? I normally take photos

 

[Chalker]

I think your screed was cured, but not dry. Was it moisture tested before tiling?
If there is any residual moisture left in the screed, this will be forced upwards and once it hits the porcelain tile it can't get out and can de bond the tile.

 

[One Day]

Was the floor checked with a hygrometer before the adhesive was laid , and do you have evidence of the results ? I normally take photos

 

[One Day]

I think your screed was cured, but not dry. Was it moisture tested before tiling?
If there is any residual moisture left in the screed, this will be forced upwards and once it hits the porcelain tile it can't get out and can de bond the tile.

And potentially soften a gypsum-based adhesive too!

 

[Kyle Knowles]

The joys of tiling aye

 

[Toni]

I didn't test it myself and don't know if the tiler did.

But it was left well over a month longer than it needed to be before the we tiled the first time (and it was force dried with ufh and dehumidifyers) and the second time we laid the tiles was a year later. I think the screed was dry but I can't be 100% until I speak to the tiler.

I'm wondering, any damp not getting through the porcelain - would it not also trap the damp of the adhesive too - so we'd always have a damp issue?

I've lifted 3 tiles. One is dry and two are a touch damp so it's not an issue with all of them. And when we had this issue last time and had to get the tiles up the adhesive was Rock hard and dry as a bone. So it seems odd that it is damp this time still.

Also the adhesive was one that allowed a bit more moisture in the screed to begin with I think. We checked that and it was more tollerant than the others.

 

[Toni]

Can I just say thanks again. All of this is very very useful in ruling stuff out and finding a problem. I really appreciate it.

 

[One Day]

@Ajax123 - Alan Jackson might have some valuable insights into just how long these screeds can actually take to dry.
I must admit - even years later I'm still wary of them giving false readings which is why I always use Ditra as another line of defence, allowing that last bit of moisture and vapour to escape....

 

[Kyle Knowles]

Threads like this really drive it home how much responsibility and pressure is on our shoulders