Thanks Zam, I should have made it clearer. The noise isn't from water hammer. It's simply from the noise caused by the expansion and contraction of the hot water pipe which is bracketed to an interior wall. I'd try unscrewing the brackets and packing something between the pipe and the wall to insulate the noise but the brackets are secured into cement sheet. I want to be sure this will solve the problem before I do this, as I've had problems before with screw holes breaking away in cement sheet. Any advice?
Michael, April 2007