Schluter sizing
My tile thickness is 8 mm, I wanted to get 5/16” Schluter based on their sizing gauge. The guys at F&D said I should get one size up “just in case”, and I believed them. I’ve finished with the window, but I had all sorts of trouble getting the trim lined up at the changes of plane. I think it is due to the wrong size trim.
I just want a sanity check: should I do the remaining parts (outside corners, curb, and transition to sheetrock) with 5/16” Schluter that I originally wanted, or should I stick with the ⅜”?
I should know better than to trust the F&D guys. They once tried to convince me that I was doing something wrong with my waterproofing, and didn’t seem to understand the difference between a WIWO and a sealed system. In fact, I’m not convinced they knew that a sealed system is a thing. Makes me wonder how many DIYers have made the mistake of mixing the two systems based on bad advice from F&D.
Ok. That last part was a bit of a rant, but I feel better now. Thanks for listening. :-)


One of the confusing parts about Schluter trim is that the sizing is based on the tile plus thinset. Not the tile alone.