Flo Fx drain
Thanks all for considering my question. I’ve done a few Schluter installs successfully (so far), and switched to Flo Fx on my most recent project given Isaac’s enthusiasm for the drain. Application is Kerdi on mud with a Flo Fx drain. I used Kerdi Fix to seal the kerdi to the Flo Fx drain. I’m noting something I’ve never seen with Schluter drains : fully several hours after use, there exists a circle of moisture (grout is “damp”) extending 2.5 to 3 inches away from the drain on all sides. Schluter drains are sloped, whereas Flo Fx is flat. Yes, Flo Fx has weep holes, but even if thinset got in the way of those weep holes, thinset is a porous material, so that shouldn’t cause this (me thinks). And I surely didn’t clog the weep holes on all four sides. Is this simply a function of the Flo Fx drain being flat, whereby there is residual moisture on the flat portion of the drain? Also, I went under the house, I see no evidence of moisture getting back under the Kerdi and down to the subfloor.
The flo fx flange does have slope, unless it was built up with too much mud under it and it raised the edges flat. Regardless, I don't think it would be the cause of moisture being trapped. These systems rely on evaporation. Gravity has little to no effect if the systems are installed properly with 95% thinset coverage under them. Could there have been some voids in the thinset under the tile around the drain that are holding water?