Anhyfix fail on schluter ditra matt? - Tile Advice

[MrB]

Hi everyone, I'm tiling a 150 meter square meters onto a anhydrite screed. Laitance has been removed by sanding, the screed is dry, was laid 3 months ago.
The screeder recommended to use Anhyfix by Tilemaster adhesives. I am also installing Ditra matt before tiling.
Started laying the ditra matt today and did a test to see how easy it would pull off and the adhesive has stuck to the screed but not the Ditra matt.
Has anyone had experience with this?
I would have thought that once the adhesive has gone off I wouldn't be able to pull the matt up with ease by hand.
How well do adhesives grab onto the ditra usually?

Ben

 

[J K Tiling Cornwall]

Hi Mr B, how long did you leave the adhesive before you tried to pull up the matting? And was the adhesive rapid or standard set? If green may take a few days to fully bond. Make sure the mix is slightly wetter and pull the mat back a little as you go to check coverage. 👍

 

[MrB]

Hi Mr B, how long did you leave the adhesive before you tried to pull up the matting? And was the adhesive rapid or standard set? If green may take a few days to fully bond. Make sure the mix is slightly wetter and pull the mat back a little as you go to check coverage. 👍

Hey JK, thanks buddy. Its a rapid setting adhesive. Had been left about 4/5hours and made sure it had bonded while wet. Will check when I go back on Monday to see if any think has changed, but I'm not confident.
I phoned Ditra technical and they don't recommend gypsum based adhesiveas they haven't been tested by them, Said to stick it down with a cement based.

 

[J K Tiling Cornwall]

Thats cool I have a anhydrite floor tiling job coming up soon as well. So much conflicting advice out there. Was going to go down a similar route, grind floor, prime and fit mat using a gypsum suitable adhesive, then tile over mat as per normal. Some people suggest tiling straight onto the screed using Anhyfix or similar, but its a large area with underfloor heating. Was looking at using the BAL flexbone but as they are plank tiles less than 300mm wide its not suitable. Some people say you can use standard adhesive if primed right? If any other tilers on here can offer their advice or experiences that would be great. Thanks

 

[Dave]

Hi everyone, I'm tiling a 150 meter square meters onto a anhydrite screed. Laitance has been removed by sanding, the screed is dry, was laid 3 months ago.
The screeder recommended to use Anhyfix by Tilemaster adhesives. I am also installing Ditra matt before tiling.
Started laying the ditra matt today and did a test to see how easy it would pull off and the adhesive has stuck to the screed but not the Ditra matt.
Has anyone had experience with this?
I would have thought that once the adhesive has gone off I wouldn't be able to pull the matt up with ease by hand.
How well do adhesives grab onto the ditra usually?

Ben

Morning, is the screed heated. ?
I also have read schluter are not keen on sticking the mat down with gypsum adhesive.
I personally Acrylic prime and use cement based for matting on heated screeds , of course after beating is commissioned and dry.

 

[MrB]

Morning, is the screed heated. ?
I also have read schluter are not keen on sticking the mat down with gypsum adhesive.
I personally Acrylic prime and use cement based for matting on heated screeds , of course after beating is commissioned and dry.

Hi Dave,
Yes it is a heated screed. It will be a underfloor water system that has been previously turned up slowly according to screeders recommendations.
You can use cement based adhesive with prime plus primer. Since Ditra don't recommend gypsum based adhesive, I will have to follow there advise and use a C2 or CF2 cement based adhesive.
I personally don't have a huge amount of experience with the ditra matt.
Can anyone who has talk about thier experience with the matt bonding to the substrate with cement based adhesive?