DO NOT let your contractor just grout your shower perimeter joints. It’s TCNA standard to use a flexible 100% silicone sealant at those perimeter joints. Also need to leave a sufficient expansion at those areas for thermal cycling.
I like the idea of doing movement joints first so you don’t accidentally get grout in there. I wonder why ANSI specifies grout before silicone? When should the sealant be applied? ANSI A108.02 - 4.4.5 states, “Install sealant after tilework and grout are dry. Follow sealant manufacturer’s recommendations.”
@@nonamuss9991 you can do it that way also, you have to remove the backer rod when the grout is fresh, and install new backer rod before before you apply silicone.