Water supply pipes rattling in walls.

Hi Karen - my guess is that shock arresters are not present in your property and to my knowledge are not normally fitted in domestic properties as standard. The problem is usually as a result of badly secured pipework. Fitting shock arresters would mean cutting pipework so something you might want a plumber to do for you. Before taking this action though I would firstly check any pipework that you can to check it's secure. Check any flexible hoses under baths and basins to ensure they are not moving when the water is switched on and off. Also check that your water pressure isn't excessively high, if that's the case you might want to try a pressure reducing valve to bring it down to an 'acceptable' level (e.g. from about 7 to 3 bar) and see if this eradicates the problem. Whilst you might enjoy the high water pressure in your home you might be a flood waiting to happen if the quality of the pipework instal is anything to go by. Hope this helps. Rick

It’s either a loose pipe that needs fixing back to the wall or a water hammer in either a tap or ballvalve causing this

this is water hammer,fitting a water hammer arrester can help,but exposing the pipes and clipping them is the best thing to do.

Change arresters

Numerous reasons, pipes with no clips holding the pipes in place, PVC piping running through holes with not enough space, WC fill valves sometimes being an issue, pipes to close together, pipes not supported under the joists etc. I am sure other plumbers can add or will also add to the question you have posted. Basically you would need a plumber to visit and to try and identify while there!