If you hear a noise that sounds like a jack-hammer in your walls whenever a faucet cuts off or when the washing machine or dishwasher is in use, you probably have a water hammer. This happens when the flow of water rapidly stops or changes direction.
One way to eliminate this noise is to install a water hammer arrester at the location of the problem. This simple to install device is nothing more than a spring or piston encased in an air chamber, usually made from copper.
As the sudden flow of water is interrupted, the air chamber cushions the blow, stopping the violent rattling of the pipes that causes the hammer noise.
Hammer arresters can be installed at washing machines, dishwashers, and water heaters; and you can find them at most hardware stores beginning around ten dollars.