Not sure if this is plumbing or landscaping...I have a sprinkler system that starts with 1/2 inch copper pipe at the house and turns into 3/4 pvc with about 10 sprinklers on it...When it shuts off there is a loud bang that can be heard through out the house...Anyone else run into this??? Thnx, Jim..
Yup, that's water hammer. It is caused by fast-acting valves like your electronic controls on the sprinkler, and those on washing machines.
Your best bet would be to look at hammer arrestors. Depending on the configuration, they make ones that you can solder to the 1/2" copper as close to the valve as possible. Sioux Chief is a popular manufacturer of them, and you can get them at box stores or plumbing supply houses.