

Pipe noises range from loud hammering sounds to high-pitched squeaks. The causes may be loose pipes, water logged air chambers, or water pressure that's too high. Anchoring exposed pipes is a simple solution; other remedies such as anchoring pipes concealed inside walls, floors or ceilings, may call for a professional.
Banging
Pipes are usually anchored with pipe straps every 6 to 8 feet for horizontal runs, 8 to 10 feet for vertical.
· If your pipes bang when you turn on the water, you may need to add
straps, cushion the pipes with a rubber blanket, or both.
· When you anchor a pipe-especially a plastic one-leave room for expansion.
· Don't use galvanized straps on copper pipes.
Squeaking
Only hot water pipes squeak. As the pipe expands, it moves in its strap, and
friction causes the squeak.
· Solution: Cushion it as you would a banging pipe.
Water Hammer
This noise occurs when you turn off the water at a faucet or an appliance
quickly. The water flowing through the pipes slams to a stop, causing a hammering
noise.
Check for:
· Loose Pipes
Remedy:
· Anchor the pipes.
Check for:
· Faulty air chambers. These lengths of pipe, installed behind fixtures
and appliances, hold air that cushions the shock when flowing water is shut
off. They can get filled with water and lose their effectiveness.
Remedy:
· To restore air to the chambers, turn off the water at the main shutoff
valve. Open all the faucets to drain the system. Close the faucets and turn
the water on again. The air chambers should fill with air.