Banging water pipe

[Burnerman]

Apologies if this has been covered before somewhere, but I've got to try and sort out this problem for a punter.
When the loo stops filling, the supply pipe bangs noisily from somewhere in the bowels of the upstairs apartment...presumably due to the pipe being unclipped. Its not possible to lift the floor, so any comments on a Water Shock Arrestor - typically available from Toolstation or similar? Would this help things? Cheers for any tips! John

 

[plummerman]

Am hazarding a guess here but is it two flats on a single main? the flat your in feeds the one upstairs?

water arrestors are ok for single appliance situations say a toilet which is banging like buggery when it's almost shut off but the back pressure is causing it to judder. If i was you i would look at fitting a mini potable water expasion vessel some where very close to the main to try and over come to the back pressure your incountering and possible slip a note tho the tenant upstairs door explaining what's happening and see if they'll let you in to try an rectify the fault

 

[Burnerman]

Cheers for the reply, Mr.p....sorry I wasn't so clear with my explanation - the apartment has its own water supply and stopcock, and the banging is indeed from beneath its own (tiled on timber) floor. Apart from the noise, there isn't any connection. The shock arrestor that I'm on about looks to be some sort of expansion vessel so I'll guess I'll buy one and give it a try- Its not possible to fit it next to the loo but the supply pipe is accessible from behind the bath panel so I'll see if it will go there....I haven't used one of these before, though. Cheers and have a good evening, John