I spoke to a builder friend yesterday and asked him about epoxy grout. He suggested it would be beyond my DIY skills to manage a neat job. :lol:
So I reckon I'll be using bal microban grout.
Meanwhile, just to show I don't always listen to reason, I decided to tile the shower ceiling anyway. :yikes:
I figured that if they started to fall off, they would just match the shambles that is the rest of the house. It's surprising how relaxed you can eventually get about windows where the original wood lintels have crumbled to dust, cracks in the walls and doors with such wide gaps that toads find their way into the kitchen overnight.