Limestone Discolouration

[Fraser Tiling]

Hello guys,
just fixed 20 metres of 15mm 900x600 tumbled limestone to a screeded floor with underfloor heating using Ultra extended set white flexible adhesive.
When I returned to seal the tiles there was a noticible discolouring to the tiles which I put down to the moisture still coming through the stone.
They were laid three weeks ago and the underfloor heating was turned on a week ago but the tiles still dont seem to be drying to a uniform colour.
I have laid similiar tiles before with the same adhesive and havent had this problem.
Instarmac have seen photos of the tiles and say the floor needs more time to dry and eventually the floor will dry, but Im worried about the tiles being stained by the moisture.
Anyone have any experience with this problem or any advise?

 

[Just Rizzle]

mines by sovereign but any decent one should do the job

 

[hmtiling]

I've got a Protimeter Hygromaster which is bob on.

 

[hmtiling]

Have you done a test on the stone on a substrate you know to be dry with the same adhesive? Surely this will show whether it's adhesive bleed or a screed issue.

 

[Fraser Tiling]

Have you done a test on the stone on a substrate you know to be dry with the same adhesive? Surely this will show whether it's adhesive bleed or a screed issue.

have got Ultra coming to site this week, and am meeting the builder again to run through the floor construction for possible faults there, but testing the tile on a dry screed with same adhesive will be a good indication.
There were some boxes and general building items left on the screed overnight prior to me starting the job, and when moved to prep the floor there was no discolouration of the screed to indicate a moisture problem.

 

[Flintstone]

I have used these same tiles recently, or at least they look the same. I went for wider joint as it looked more suited to the size and uneven edge of the time. I used tile master standard set white with no problem, onto an old floor. At 15mm thick, I think it would take a lot of moisture just from the adhesive to reach the surface to that extent. I'm voting the screed is wet still

 

[Flintstone]

 

[Flintstone]

if ditra was to be used as a waterproof layer, what happens to the trapped moisture in the screed?

 

[macten]

if ditra was to be used as a waterproof layer, what happens to the trapped moisture in the screed?

The interconnected air channels between the cavities on the underside of the Schlüter®-DITRA 25 matting remain open. This allows moisture in the substrate to evaporate, therefore neutralising vapour pressure.

 

[Flintstone]

Very fancy. I've never used the stuff myself, mainly as I've never come across it other than on this forum.

 

[White Room]

View attachment 80585

Why do people not decorate the new plaster before the tiles are fixed ?

 

[One Day]

The interconnected air channels between the cavities on the underside of the Schlüter®-DITRA 25 matting remain open. This allows moisture in the substrate to evaporate, therefore neutralising vapour pressure.

Good answer. But to add: this won't help on a dripping wet screed. Still follow Schluter's guidelines on moisture...

 

[Flintstone]

Why do people not decorate the new plaster before the tiles are fixed ?

Often it's down to timing. This particular job was quite a bit of building work to make a larger kitchen, then kitchen went in and tiling followed straight on

 

[Perry]

Fraser how are you? Did you seal the tiles first? Pete James

 

[Fraser Tiling]

Hello Pete, just replying to your post after long telephone conversation, obviously cant say too much but staining resolved by customer with Wexa after Instarmac site inspection.
As explained on phone, customers own results from tests resulted in a satisfactory fix.
Although contradictory to Instarmacs lab results.
I've been exonerated of bad workmanship, and final results are no longer my concern.
Thanks for the interest though Pete, and nice to hear from you again.

 

[CJ]

Why do people not decorate the new plaster before the tiles are fixed ?

Because have you asked a painter NOT to paint below a certain line, because it will be tiled......and then you turned up, and 15 coats of Silk have been wacked on.

 

[Lou]

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