Thank you for the responses on the insulation. I too am leery that it will work, but I figure if it might help to lower the sound, I’d be thrilled. Basically, this noise happens after my neighbor (an early riser) uses the sink and shower each morning. After the appliances are off, there is a banging noise, which is frequent and loud for about 25 minutes or longer. Thought it was water hammer, installed arresters, but that did not change anything. Went in wall to secure pipes, but that did not change anything. The noise, however, does NOT happen if you try to repeat it a few hours later, it seems only after the sink has not been used for a good 24 hours does this happen. At a loss for what else to do other than insulate. Any suggestions, ideas, recommendations appreciated.
Sure sounds from how you have explained things to be most likely the expansion and contraction of waste water pipes following use of a handbasin. Once when they are heating up and once when they are cooling down. The materials used are more than likely PVC hence the loud sound. Insulation of the cavity providing the material is packed tightly round the waste pipe will assist in easing the problem for you. Otherwise set your alarm and start mowing the lawn outside your neibours before he rises to get your own back!!!
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