Limestone Discolouration - TilersForums.com

[One Day]

Back home now and had a closer look. I didn't pick up on the uncommisioned ufh part.
I'd say that it's primarily the additional moisture of the extended set not yet gone, and in part - moisture rising from the screed still.
Good sign is the dryness around the grout joints. I think this will dry out but could take quite some time yet...

For future - please use Ditra and a rapidset. That would mean you could fix safely onto uncommissioned heated screed and no risk of residual moisture lurking in the adhesive.

 

[White Room]

Was there no decloupling mat fitted ?

 

[Fraser Tiling]

The underfloor should have been commisioned before tiling. I'm pretty sure this is the moisture from the screed trying to get out.

Thanks Chalker, that makes alot of sense, will check with the builder that the UFH was tested before hand, I must admit I cant remember whether I asked, to be fair with their experience they should know.
Do you think there would be any staining if the screed is the issue?

 

[Fraser Tiling]

Was there no decloupling mat fitted ?

no, wasn't deemed necessary by the builder, dont think there would be an issue if it was used

 

[Fraser Tiling]

Back home now and had a closer look. I didn't pick up on the uncommisioned ufh part.
I'd say that it's primarily the additional moisture of the extended set not yet gone, and in part - moisture rising from the screed still.
Good sign is the dryness around the grout joints. I think this will dry out but could take quite some time yet...

For future - please use Ditra and a rapidset. That would mean you could fix safely onto uncommissioned heated screed and no risk of residual moisture lurking in the adhesive.

agreed, I would never spec a floor and not use a decoupler

 

[J Sid]

no, wasn't deemed necessary by the builder, dont think there would be an issue if it was used

Deemed not necessary by builder, his trying to save money and when it all cracks he will blame the tiler as the tiler is the expert and should know what to do.
If its coming from screed it could take many weeks to dry out now. Tell the builder, due to his insistence to not use a uncoupling membrane he must now wait until floor is completely dry be you can seal it. He must also keep everyone off it or it will get stained.

 

[Fraser Tiling]

Thanks to everyone that's posted on my thread, confident we have found the cause of the problem.
This forum is a brilliant tool for just these kinds of issues, cant thank you guys enough.

 

[Fraser Tiling]

Deemed not necessary by builder, his trying to save money and when it all cracks he will blame the tiler as the tiler is the expert and should know what to do.
If its coming from screed it could take many weeks to dry out now. Tell the builder, due to his insistence to not use a uncoupling membrane he must now wait until floor is completely dry be you can seal it. He must also keep everyone off it or it will get stained.

agreed, often builders offer the customer the option, and depending on budget the customers have the final say.
Unsure of the details on this particular job, but you're right, ultimately it has fallen on my shoulders when shortcuts are taken.

 

[Just Rizzle]

dosnt matter how long you've been tiling you learn some thing new every day

 

[Fraser Tiling]

dosnt matter how long you've been tiling you learn some thing new every day

perhaps not every day, but yeah this game keeps you on your toes and bites you when you become complacent.
Just cant take anything for granted.