I've reviewed all the posts that refer to noisy pipes but haven't found any with my problem. So, here it is. A few months ago, the local water company did some work on some of the water lines. They swear it wouldn't cause the problem I have but it did not start until after the work was done.

Here's the problem, one of the water lines in the house vibrates. From what I can tell, it provides water to the commode in the main bathroom. It is not consistent as to when the noise starts, how loud it is, how long it lasts, or when it stops. I have only been able to stop the noise by turning the water off to the commode. Some days it's worst than others in terms of how loud it is and its frequency.

I have been in the basement a couple of times when the "banging" or vibrating sound begins and have actually identified the pipe but not the cause. The straps holding the copper pipe in place appear to be in tact.

I have put a pressure guage on the outside water faucet (that's how the guy at the store said to do it), and the pressure rates in the acceptable range. Plus, since it only does it with that one pipe, it seems reasonable that the pressure is correct.

Any ideas? Suggestions?

Thanks.

It could be a problem called "water hammer". Why it started only after the water company did work is a mystery. If it is water hammer, there are a couple of ways to cure it, if you have access to the piping. A device can be installed on the piping which will absorb the force of the water. Or, what is sometimes done is to add a vertical piece of piping in the offending line, which also can relieve the force of the water.
However, water hammer usually occusr only when one uses the water line in question...in other words, it shouldn't happen at random times, but only when you flush that water closet.

I guess I didn't help much, did I? Hopefully a real plumber will arrive with a much better analysis.

You have have gotten some dirt in the ball ****. If you have a Master Plumber one that has a black block that runs up and down the main shaft, then you can remove the black cap at the top and turn the white piece in the proper direction to remove it and check for dirt. Be sure to turn off the water first. Once you have it apart, turn on the water slowly to see if any dirt comes out. If it still does it after, try replacing it. If it isn't the type I distribed, buy a new Master Plumber ballcock.

A side note: If you know your water was being worked on, be sure to run it through a outside spigot or on the tub faucet first since they usually have the biggest holes and no screens to block dirt.

Another loud vibration can be caused by a loose bib washer in the supply valve under the stool (or sink). This can be detected/eliminated by turning the valve farther to 'open'. You can eliminate this type of noise by taking the supply valve apart and tightening the bib screw or replacing the supply valve.
This loud vibration can also happen in faucets if the bib washer is loose in the faucet stem.
I agree that 'water hammer' can be loud and annoying but it is short in duration and only happens at the end of the refill cycle and makes a sound like someone hitting the pipes with a hammer once.
As said in the previous posting, the washer inside the ballcock could have something in it and it can be checked easily by removing the top with a quarter turn (don't force it). In my part of the country Fluidmaster 400A is the brand most likely used.
As always, 'MAKE SURE THE WATER IS OFF' before taking anything apart.

here, i got this from the Bob Vila site... It is caused when there is something in the pipes that can move as water is flowing. Most often it is caused by loose washer on a valves.

But it can also be caused some debrie in the lines.

Typcially this is restricted to a single outlet and is caused by that faucet's washer or the stop valve.

But if it is the whole house and both hot and cold then is some common part.

If you have a Pressure Reduction Valve that is the most likely place.

But it could be the main shutoff. And maybe even the water meter.

Also a whole house filter or water softener. - good luck, -Fishfool @ The Reef Tank