knocking cold water pipe..any plumbers

[makemineagin]

The cold water pressure in ES seems higher than the rest of the house. When the tap is switched off one loud knock through the pipes and the same when the shower goes off. I do hear it slightly with other cold water use around the house but not as loud. any suggestions..concerned that the pipe will blow under pressure.

[PigletJohn]

What is "ES?"

Have you got taps with a ceramic disk (quarter-turn on to off)?

Have a look at the pipes and tell me how they are clamped to the wall, and how far apart the clips are.

Pipe joints will not come apart if they have been properly fitted.

[makemineagin]

oops sorry ensuite, pipes from the sink underfloor then under show tray:o. If i add more clips will this stop the banging sound. Noticed this more since water board did some work locally and village had no water supply.Happens when the shower or cold tap is turned off. Alot quieter if shower or sink tap turned to hot.

[PigletJohn]

clamping them firmly and frequently will help. You probably have loose floppy pipes that are able to shake or vibrate. If they run very close to a wall or joist then plastic clips, screwed firmly to the wall or joist, will do it. If they are spaced off the wall you can get things called "munsen rings" which fit an adjustable stem onto the wall. They are brass and more expensive.

the common sizes of copper pipe are 15mm (basin) and 22mm (bath), but if you have a combi boiler and no tank, the bath pipes may be 15mm. You will be able to see the difference.

Plastic pipes will be a different size.

it will be useful to know if you have quarter-turn taps.

If the WC cistern buzzes or bangs you need a different fix.