I'm going to put new vinyl tiles on top of old sheet vinyl floor, in a laundry room. My wife wants to use what's called Luxury Vinyl Tiles, which have a rounded edge and are groutable. There are grouts like Fusion Pro which specifically mention vinyl tiles as a suitable tile type.
However, my fear is, that because the floor does not have a cement board on it, and it is prone to frequent vibrations from the washing machine, the grout will fail quite soon (will crack, become loose, etc.) Do these polymer-based grouts have some flex in them, or is grouting vinyl a totally bad idea?
I know I can install these tiles without any grout, but my wife prefers the grouted look.