I have a brand new house built 5 months ago. I can hear random knocks and single bangs in my attached bath and bedroom ceiling. The bathroom sounds metallic, and the ceiling sounds like something is hitting my roof. As if its in the attic or someone threw a rock on my roof. I kept convincing myself its pigeons landing on my roof, but no way can they be this loud. The house is under warranty for one year. I called the contractor and he said the house is settling in. Creaking, I can accept but these random knocks wake me up and I can't sleep. There is also water hammering associated with the sprinklers. The sprinklers I can prove and recreate at will, but the ones in my room are harder to reproduce because NO water is on or recently just turned off. They do however occur several times at night while I'm trying to sleep. They do not sound like the sprinkler hammering which is really obvious. Its more of just a knock. My question is this, what is my best way to convey this problem to the contractor? If I say its plumbing, they'll send a plumber, but they don't send people all that often. Should I demand they send a fix it person to some and listen to the sounds? Or is there a way I can inspect the attic so I can pinpoint what it is? I sound stupid on the phone because all I can say is I hear knocking in my ceiling and bathroom. I'm almost sure its pipes, but I'm not an expert.