my house has cpvc plumbing and is one year old. whenever we turn the hot water on anywhere in the house we hear a popping noise that lasts for around 1-2 minutes and then it stops. also after a shower and the water turned off we can hear a popping sound from the pipes about once every minute for about an hour. my builder says this is normal from cpvc plumbing because the pipes are expanding when hot. is this normal? it is very aggravating hearing this noise.

CPVC Noise