American Standard told me that my shower head was leaking because it was not installed high enough above the tub faucet, even though we followed installation instructions. Can't redesign the roof, don't want to replace the whole thing with another product. My plummer says that it is possible to get a shower head with a stop cock, from a supplier, perhaps in CA. No one around here has one, they are all designed to leak.
Ledgerock COnstruction, January 2005