View Full Version : Need help with cold water hammer in newly piped shower

02-10-2008, 06:18 AM
In the last couple of weeks I had my shower gutted and new copper pipes and pan and tile put in. All new. I have been waiting for our framless shower door to come in-which is in and will be installed along with our shower head-hand held and trim kit tomorrow.

The problem is that since this has been done-or maybe a few days after the shower was installed there is a knock occuring in the new pipes when the toilet is flushed (when it is finished refilling) or when the cold water faucet is shut off anywhere in the house.

They are coming back tomorrow and I want to be able to have that fixed and not have them say......"Lady...it is nothing." I know it is something not good-water hammer-air....which? .....and what do I ask for and what should I watch for.

Thanks-middle aged lady who doesn't want to be taken!

02-10-2008, 02:02 PM
It sounds like they did not anchor any of the new piping. It usually happens only with fast closing valves like a washing machine, icemaker, dishwasher, etc. If you can make it happen with any valve, in my opinion, it's a sign of poor workmanship. A hammer arrestor(s) may not be enough to stop it. You normally only need a hammer arrestor on those quick acting valves. For the toilet, you may be able to change the fill valve to something like the Korky quietfill, which doesn't shut off as quickly as say a Fulidmaster 400 series does. That part is around $10, and might be eaiser to deal with than trying to find a place of a hammer arrestor for that device.

They may need to open the wall behind the shower (or anywhere new [pipes were added or moved) to install some anchors to keep it from flopping around. A real pain after you've probably painted and cleaned up.

02-10-2008, 02:22 PM
Yes they have retiled the wall and there is only an opening with the values sticking out. It is not a horrible thump-if it was left that way will future damage happen?

Could it be air in the pipes since the shower hasn't been turned on yet?

thanks again!

02-10-2008, 05:46 PM
If anything, air in the pipes would dampen water hammer.