What causes rattling pipes?

Answer 1

This problem is caused by the water lines not being properly isolated. It can be easily fixed but only if your water lines are accesible. It usually means that either in one or many places your water lines come into contact with the wood of your floor joists. All you need to do is get plastic pipe hangers that go between your water lines and your joists.

• You might need to install an anti-bounce device into Plumbing. It has to do with harmonic bounce.

• A water hammer arrester will help solve pipe shudders due to quick closing water valves in your home.

My thought is the rattling pipes need to be clamped down securely to some wood trusses. You cut water on and it's rushing down the pipe. You cut it off and the flow is abruptly stopped causing the force of that flow to crash but try to continue it's movement and actually make the pipe physically move. Empty sealed vertical water pipes used to be installed in water lines to create an air cushioning. Now days there is some kind of short lasting air pressure regulator called for attachment to the water heater. *You should have water hammer arrestors installed at your clothes washer and dishwasher. These are quick-closing appliances that create water hammer. You can purchase the ones for your clothes washer that will install between the hose bibbs and the waterline hose going to the washer. The one for the dishwasher(if you have one) would have to be installed inline and are different from the ones I just described, are usually installed under the kitchen sink.*

Before you purchase anything though, check for a simple cause first. If your home was built during the 60's or later and has metal pipes, look near your laundry tub/sink. You'll hopefully will see two air chambers which are vertical pipes about a foot long or so [unless the builder cut corners]. When these are full of air they will dampen/eliminate the pipe rattle when water is shut off quickly. Over time these air chambers fill with water [become water logged] and fail to dampen. The fix for this is to simply shut off your water supply and open up ALL faucets on ALL floors to let all your pipes drain out. This will allow the air chambers to again fill with air and could very likely cure your pipe rattle dilemma.

Another cause of pipes rattling or shaking could be undersized piping. My friends 3 bay auto shop and kiosk is all piped in 1/2" so when a few or more taps are running everything's fighting for water. It gets prettty redonk. When only a couple taps run its fine.

Answer 2

Rattling pipes happen when they're not properly strapped to the framing and the water pressure is not properly setup. I would call a plumber to fix such an issue. The only way to make sure they never rattle is to one open up the wall and strap the pipes to the framing or two from a basement or an attic try to reach the area where the rattling occurs and strap the pip to the framing.