S2 adhesive & membrane required?

[Rich Midge]

its because the adhesive is fixed into the cavity's mechanically on Ditra and if fixed by an S2 adhesive it will stick to the plastic and it would loose it's uncoupling properties

Good stuff, I was on the right track then.

 

[Mark@Tilemaster]

There appears to be some conflict of interest here. As a tile adhesive manufacturer, we will always advise the correct product from our range to suit the application needs.

As some members here have already pointed out above, Schluter do not advise an S2 adhesive being used either to adhere, or tile over Ditra matting, as the strength/deformability of the adhesive can negate what the Ditra matting is there to do. Dural UK are happy with an S2 adhesive being used, and they have seen the results from Germany, as we would be if Tilemaster Anti-fracture matting was to be used with an S2 adhesive.

These were both checked with the respective companies yesterday, and a scenario we used with both manufacturers was that of an installation of a resin backed natural stone over a green screed that had piped underfloor heating. The recommendation would be to use an uncoupling system with natural stone onto the substrate. An S2 adhesive isn't needed in terms of flexibility, however the polymer content of the adhesive is needed to adhere to the resin backed stone.

For this installation, we would advise using Tilemaster Ultimate (S2) tile adhesive to stick the Ditra matting down, as Tilemaster Ultimate is our green screed adhesive. For installing the tiles, we would advise back buttering the tile and troweling the Ditra matting with Tilemaster Ultimate (S2) due to the polymer content.

We would stand by this advise in terms of our product, however some advise might need to be sought from the manufacturer of the uncoupling membrane in this instance.

 

[Old Mod]

Thanks for that @Mark@Tilemaster, really appreciate you taking the time to clarify those points.

 

[J Sid]

makes sense, but Ditra would not, from my conversations with them, guarantee there product if a S2 adhesive is used on top to stick tiles. So another uncoupling membrane is needed. If it was a green screed then that only leaves Durel, I believe.

 

[Qwerty]

makes sense, but Ditra would not, from my conversations with them, guarantee there product if a S2 adhesive is used on top to stick tiles. So another uncoupling membrane is needed. If it was a green screed then that only leaves Durel, I believe.

To be fair that may be because they haven't any test data using an S2, or because some S2 adhesives are a one part rather than 2 part and they have only tested 2 parts S2 adhesives. Any idea @Schlüter-Systems Ltd ?

 

[J Sid]

my understanding is, if the S2 adhesive sticks/bonds to the plastic the mat will loss it's uncoupling properties .