Houses have sounds. Some are normal and you learn to live with them. Others are an indication of a problem that needs correcting. Most plumbing noises fall somewhere in between. Banging pipes, water hammer and whistling sounds can all be corrected. If you have access to your water-supply pipes, the solutions may be fairly simple and affordable. But it can be another story if the pipes are covered by drywall.
Water hammering is caused by the quick shutoff of water-supply lines. The energy of flowing water has to go somewhere, and when a valve is shut off, the pipes cars flex arid "hammer" against anything close -- nearby studs, joists or other water pipes. Solenoid-triggered valves, like those in dishwashers, washing machines and water softeners, shut off almost instantly. This instant shutoff not only causes the most ferocious hammering, but also puts a strain on flexible supply hoses and soldered copper fittings. Hand-controlled faucets usually don't cause as much hammering, because the shutoff is more gradual.
Sometimes the solution is as simple as adding one or two supports to the affected pipe. A piece of felt or rubber between the pipe and support can further deaden the noise. This felt cushion works especially well for pipes that are too tightly anchored. These pipes make clinking or ticking sounds when a fresh flow of hot water causes the pipe to expand.
If adding or cushioning pipe supports doesn't solve the problem, you may need to add water hammer arresters. Arresters have a chamber of air that acts as a cushion for the force of water to push against when the flow is stopped. If your home is already equipped with arresters and you still have water hammering, the arresters may need maintenance or replacing.
Whistling sounds are usually an indication of a shutoff valve that's not fully open or of high water pressure. High water pressure can exacerbate water hammer problems. In some cases, you may need to install a pressure-reducing valve to lower water pres sure to the house; however, lowering the pressure may negatively affect upper-floor fixtures.
Water Hammer Arresters
Arresters have an air chamber that cushions against the moving water when the flow is stopped. If your home has arresters and water hammering persists, the arresters may need maintenance or replacing.
Vertical air chambers are simply a capped length (usually 12 in./30 cm) of pipe added to a supply line. These arresters eventually fill with water as the air gets absorbed into the water supply. If this happens, turn off the main water supply and open all the faucets to drain the lines, then close the faucets and turn the water back on.
Manufactured arresters offer a more permanent water hammer solution. These arresters use a rubber-gasketed piston to isolate a pocket of air from the water in the pipes. The closer you locate the arrester to the affected valves, the better. The supply pipes for dishwashers and water softeners, which are frequent offenders, are usually accessible to add arresters.
Screw-in arresters offer the perfect solution to water hammer caused by a washing machine. These mount between the faucet and the washing machine supply hoses. Look for arresters at hardware or plumbing supply stores.
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MINI-RESTER" WATER HAMMER ARRESTER Tee connection Uses pressurized cushion of air to absorb the pressure spike Dual O-ring piston separates the air cushion from the water system to ensure permanent protection from waterlogging Stops banging pipes Easy to install Arresters can be installed vertically, horizontally, or any angle in between Carded 5/8" :More
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Isolating Sound
Pipes can bang, rattle and squeak where they con tact wood. An oversized hole with a pipe insert and pipes hung from special J-hooks will isolate vibrations and reduce noise.
Pipe inserts are split and can be installed where pipes pass through a support block and the diameter of the hole around the pipe is large enough to accommodate the insert. Generally, it's best to put these in when you initially install the pipe.
i-hooks can be used during new construction or they can easily be retrofitted to existing pipe. Nails through the side of the i-hook hold it to the supporting joist. Securing felt between the hook and joist helps to further isolate any vibration.
Pressure-Reducing Valves
Install this valve near the water meter. Cut the pipe and add adapters and unions. Screw on the valve and tighten using two wrenches. Set the pressure with the adjusting screw on top of the valve.
