Hi
Pic shows 2 bath addition to house approx 12 years ago.
No problems until... within the last 6 months there was a leak under
The slab between " A & B" in picture.

Instead of busting slab, I decided to re-route the copper lines from
Point A... up to attic, then back down to point B.

So alls OK until last night when I closed the faucet at location C.
I heard a noise never heard before, and from reading around here,
I think it may be what's called water hammer.
From what I could tell, sound was near location B.

ALL water fixtures in sketch have air chambers. (or had air chambers)

The newly routed lines going up from H/W (hot water unit) no longer have the air chambers ( side sketch - copper though attic ) I just didn't think of it.

Should I have installed an air chamber where the 90 deg turns down to location B ?

Or any ideas of why this has started after 12 years or after 6 months of new lines.

Thanks
Danna
http://draftingdan.com/PICS/addplumb.jpg

Should I have installed an air chamber where the 90 deg turns down to location B or any ideas of why this has started after 12 years or after 6 months of new lines.
I guess you could have installed a air chamber in place of a 90 on top of the loop but a better explanation would be that the installed air chambers have loaded up with moisture and need to be recharged.
"Water hammer" happens when you abruptly shut off the water. You have at least 40 pounds of pressure pushing the water flow. The weight of the water hitting a 90 degree bend causes the sound that you hear. We put in shock absorbers,(air chambers) to cushion the hammer much like the shocks on your car.
Back in the 60's we were required to to put shock absorbers,(air chambers) on all bath lavatorys and kitchen sinks. Over time water and condensate built up in them and they must be recharged. First turn off the house at the main house shut off valve. Then open hot and cold faucets at the farthest bathroom to prevent air lock.(This is important.) You will find under each fixture little brass or chrome valves. These are called angle stops. With a small pail held under the angle stop to catch the run off look under the handle of the stop and you will see a nut with the stem running through it. This is called the bonnet packing nut. Put your wrench on it and back it off counterclockwise. Now open the stop and remove the stem and washer assembly, The stop will begain to drain. When it has quit draining reassemble the stop and move on to the next one. Do this on each one of your angle stops. There will be six of them in a two bath home. When you are done, close off the faucets you have opened, turn on the water to the house, and give yourself a pat on the back.
You have just recharged your air chambers and saved yourself a hefty service call bill. Hope this helps you out TOM

I do not see a drain on my valves.

That section is is fed by a seprate water line apart from the rest of the house.

If I close water and open all hot / cold lines to that section, will it not drain enough to
Recharge the air chambers.

Thanks for the reply.

http://draftingdan.com/PICS/addplumb2.jpg

I do not see a drain on my valves That's because there is none. Go back and read my instructions.
If I close water and open all hot / cold lines to that section, will it not drain enough to
Recharge the air chambers.
First turn off the house at the main house shut off valve or whatever shuts the pressure down. Then open hot and cold faucets at the farthest bathroom to prevent air lock.(This is important.) This is why you must remove the bonnet packing nut off each lavatory and kitchen angle stop and drain each air chamber individually.
Good luck, Tom

I see what you mean now...

This noise only happens from location C.

Do I still need to drain all valves ?

Thanks

I see what you mean now ........
This noise only happens from location C.
Do I still need to drain all valves ?
Thanks
I would start at that batrooms lavatory and check for hammer after. However, If One set of air chambers are loaded up it's a good idea to recharge them all. Good luck, Tom

Do you see some major flaw... in the way I went about repairing what was a leak under the slab ?

Also, the other part of the house is 30 years old, never had this water hammer problem.
(knock on wood)

So why would this happen to this new section after only 12 years...
Or more suspiciously, 6 months after I made a repair ?

Thanks for your replys.

Do you see some major flaw... in the way I went about repairing what was a leak under the slab ?
Short of taking up the slab you exercised the only option you had left. When we repipe a house that's how we pipe to a fixture on a inside wall. We jump up it the attic and drop down the inside the wall. I can find no fault with your repair. Cheers, Tom