hi
to my knowledge this is caused by cold water feed pipes not being clipped correctly. either insufficient clips or crap quality clips.
fact is i can hear my neighbours water hammer. he has water plummed into his garage. i have a detached house, which is built on a slope. so the gap between the founds and floor boards is about 5-6 feet on one side. his garage is 2 feet from that wall, so that space is probably acting as a sound chamber.
my neighbour has a particular obsession with his hose pipe

. if this makes a difference.
i gave him some pipe clips, which he fitted and seemed to cure the problem initially but the problem is now back. anything else i should be looking out for, to help him cure my problem.

i was thinking of those over-lock clips.
cheers
kevin