We're remodeling our bathroom and decided to use the Schluter kerdi membrane under our tub surround. The mortar mix I bought from the Schluter distributor looked "cakey" to the installer, so he decided to substitute UltraFlex for the unmodified thin set. I did not know about this exchange until last night. The tile has already been installed, but not grouted yet.
I called the Schluter distributor for guidance and he said that the problem is that my tiles will migrate and/or not stick.
Does anybody have experience with using modified mortar with Kerdi? Will it hold the tiles?
I'm trying to figure out if I start the demolition now or do I move forward with the grouting.
I would really appreciate hearing your experiences. Thanks!
The person to whom you spoke with at the distributor has no idea what he/she is talking about. The tile will not leave the scene, it'll stick fine.
Schluter recommends unmodified thin sets to bond tiles over Kerdi & Ditra because unmodified dries chemically and need no air in the process. Since Kerdi & Ditra are non porous they may retard the drying time especially if large impervious tiles such as porcelain are used. No problem really. If you can, just let the tiles dry and extra day or so if possible. Get grouting.
TILE GUY - retired- TROY, MI - Method & Product suitability consulting.
Thank you so much for the information, Jazman! The dry time issue makes a lot of sense. We have five course of 12x12 porcelain tile with 6x6 along the top. We'll give it a few more days to dry out.