Messages and Online Forum Q&A

Re: Water Hammer - Every Faucet

From: info@builderswebsource.com
Category: Plumbing
Remote Name: 63.198.181.43
Date: 16 Oct 2000
Time: 06:25 PM

Comments

Is there anything that changed recently in your plumbing? A new water heater? A new faucet? A new washing machine? A sprinkler system? A new water meter? If so, this may be the culprit. If nothing has changed, and you're sure about that, there are a few other possibilities:

1) Some homes have built-in water hammer arrestors -- sometimes near the washing machine or other location where quick-acting valves are commonly found. If these devices have failed, it's possible this could suddenly cause the problem you describe.

2) Sometimes plumbers install permanent "air chambers risers" at some valves. These are 12-24" extension tubes (usually copper) designed to dampen water hammer. However, there is controversy over use of such air chambers, as they can fill up with accumulation of minerals and other "crud" in the water supply. Or they can become "waterlogged" and eventually, they lose their effectiveness. Generally, a well designed plumbing system doesn't require such air chambers in the first place, but they are common nonetheless. Water hammer is due to a shock wave in the system. If the supply and branch lines are properly sized, experiencing water hammer on every faucet would be highly unusual. If you believe you have risers, check to see if they are accessible (such as near a washing machine, etc.). If so, they may need to be re-injected with air.

3) Another problem could simply be a loose pipe strap. Sometimes, if a pipe is not properly secured to the house framing, it can vibrate against the wood, creating a hammering sound. If any of the plumbing is accessible from a crawlspace, check to be sure that it is fully secured. This won't help you if the problem is in a wall, but you might get lucky and spot a problem.

Some other questions are: Does the problem subside after turning on the faucet for a few moments? How many fixtures are there in the house (including all toilets, sinks, tubs, showers, etc.)? Do you have copper or plastic plumbing (water supply)? Is the water heater gas or electric? Is it original? Do you have a water softener?

Please reply back with your findings and answers to our questions and we can help to narrow the cause. By the way, a good technical reference on this subject is available on Builders Websource at:

http://www.builderswebsource.com/techbriefs/waterhammer.htm

Builders Websource

Article Tools

Builders Websource® is a corporate member of ASTM International—a non-profit engineering body dedicated in part to the standardization of building materials specifications, products, systems, and test methods for improved health, safety, and reliability of residential and commercial structures.

Copyright © 1999 - 2018 Builders Websource®, a BUILDERA™ company. All rights reserved.