Liquid membrane, Durabase FX combination question - Tile Advice

[Claude]

Hello all,

As i progress with my project I ran into a doubt as follows: I am currently tiling a bathroom floor. I have laid down a single coat of a liquid sealing compound (weber 822), but then decided to lay Durabase matting over this, as I believe it will work better on the different joints and separate parts i have on the subfloor, where the liquid compound would eventually fail.

To be clear, this is Durabase FX, which is the 0.5mm felt-like mat, similar to Schulter Kerdi, not the decoupling plastic matting similar to Ditra.

I plan to use PCI Flexmortel S2 between the tiles and and mat. (I do understand that S2 isn't the best choice on Ditra/Durabase CI but it has been specifically recommended for the tiles/Durabase FX combination that I have. I hope that recommendation is sound!)

I am however worried about fixing the mat using S2, due to the the waterproofing compound already in place. Will S2 cure effectively when placed between two waterproof layers? (Also taking into account that there is only one coat of liquid compound)

My other option would be to go for an epoxy mortar such as Webex 844, but this is four times the price and hesitating.

Any ideas?

thanks and regards,

Claude

 

[Claude]

Hello all,

so i've done a test by using the S2 adhesive to bond two sheets of membrane using a 4mm trowel (I figure if the membrane is not going to allow breathing, then if I use two sheets together would be a siutable test...)

3 days later, I was able to pull the thing apart. About 1cm into the edges was noticably darker and more moist than the edges.

Question : Is this normal? Should I have let it cure for more than 3 days?

... or should i really go for a reaction based adhesive?

thanks a lot in advance,

Claude