In article , "Ian
Stirling" says...
Dave P wrote:
"Rob Morley" wrote in message
t...
In article , "a"
says...

Is it not just a pipe that isnt fastened securely to a wall and the
pressure
increase when turning off a tap makes it bang against the wall?

That's what I'd suspect - find the loose pipe and fix it securely, or
wrap it in insulation so it bangs more gently :-)

Well I agree it might be that, but if it is, it's impossible to
isolate...trouble is it could be anywhere under the first floor, which has
just had a new carpet laid professionally; or could be within an area now
boxed in by plasterboard. So hopefully not!

Have someone turn on and off a tap.
Place your ear against a wall.
Repeat until it's loudest.

You can try using a length of dowel or similar as a "stethoscope" to
make it a bit easier.