Using modified thinset cement and waterproofing membrane -recommended or not ?

[MiniMe4Eng]

I am reading this website

https://makeitright.ca/holmes-advic...mortars/#:~:text=If you’re,not cure properly.

and it says these

Inmy case the membrane is going to be Redguard

If you’re looking to set tile over a membrane, you typically shouldn’t use a modified thin-set mortar, as the drying process takes far longer than unmodified thin-set mortar. This is due to the mortar being sandwiched between 2 impermeable materials, being the membrane and tile, which does not allow for fast drying. The moisture can’t escape, so it may not cure properly.

With standard modified thin-set mortar the Tile Council of North America says it can take from 14 to more than 60 days to cure properly. In this case, an unmodified thin-set mortar would be best suited, as the mortar is able to properly hydrate and cure faster (typically within 24 hours).

Are the above correct ?

 

[Ron]

That's mostly correct. Modified thinsets have polymers added to increase flexibility and to slow the curing process to reduce cracking potential. The polymers are proprietary, but mostly some form of latex. RedGard should be compatible with either type of thinset. I question the estimate of 60 days for full cure on any thinset. My experience is that it cures a little slower than unmodified thinsets but still within a reasonable range.

 

[Envelope3]

It is hard to generalize as the quality and composition of thinsets greatly varies. I see a lot of people using versabond (including myself) for tile applications over membranes and not having an issue, but versabond is known to be only "slightly" modified as compared to others. I would not utilize versabond, however, between membranes such as Schleuter's lapped membrane system.

 

[dik]

My experience is similar to Ron's... and that the time period should be scheduled for as long as possible; I've never seen one cure in 14 days, but then I've never seen a Sasquatch, either.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik