split pebble wet room

[prem]

Just about to do a wet room (shower area ) in split pebbles, what is the best grout to use with the bigger than normal gaps you get with these tiles? Using Ardex flexible adhesive, or anything better out there. Been out of the game for a while.

cheers

[aeromech3]

Are they attached to a backing and then you will use Ardex?
What is the substrate (concrete, backer board, wood)?
For grout if you need colour then Ultracolor Plus FA by Mapei; if not Ultra Plus Max.
Are you going to use a sealer?
In Far East the actual pebble showers you find in resorts are just set in Thinset mortar!