Having bathroom remodeled. Shower will be on exterior wall. What should be used for insulation and what materials should be used for walls and ceiling. I want to educate myself and make sure the right materials are used and no one cuts corners. Thanks J

Hey J, the outside walls should already be insulated with some material. If possible, put the plumbing on an inside wall, even if the shower is on an outside wall, particularly if you are in a very cold climate. Other wise, R-13 fiberglass would be good. Bathoom drywall should be the green type, (I've seen some purple too), wax impregnated to reduce moisture intrusion. Make sure you use a bath vent fan even if you have a window.

I agree that gtreenboard is good for the walls but not any wet area. Wetr areas need a tougher water resistant material like wonderboard, cementboard, Hardieboard, etc. You also need to install a vapor barrieron top of the insulation before installing any of the previous mentioned materials. Are you planning to tile the shower or what?