I'm working with a home builder to have two shower heads in a master bath shower. The builder proposes have two shower valves, one per head. Is this recommended/required or is the builder just trying to charge me more for another part?
I have two heads in the master, I don't remember any charge but I guess there was. You just add inexpensive shut-offs on each head , works fine. BUT , in the US , regulations require that these shut-off valves leak, so if you have a head turned off ,it will still drip. We usually have both on at the same time. It did take a couple trips to the "big box" store and one trip to the plumbing store to find out that these shut-off are required to leak ( in US).