cpvc lubricant

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briandm

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I'm the unfortunate owner of a house plumbed with cpvc. Every time someone turns on the hot water after it's been off a while (so water and pipes of the hot water line start off cold), I hear creaking in the walls. I know what it is - thermal expansion of the pipes that's extending the pipe down and through the floor plate inside the wall and it's rubbing in the hole ( I cut out a piece of my garage wall and can see it moving about 1/8". It's not just pressing on one side, but rather is in a hole that it seems has no margin or gap on any side.

I have 2 concerns:
1) just the annoying noise
2) I'm aware of the fragility of cpvc and am concerned that this catching rubbing ain't doing it any favors.

I could cut the pipe out, widen the holes, and then replace - but that would be a non-trivial amount of work as it's in a few locations, one of which is a finished wall that would be more difficult to patch. So I was wondering if maybe I could use some sort of lubricant (silicone?) to help it slip through better without catching. It would be a super simple first option to test out. On the finished wall, I might even be able to get by with just a couple small holes in the finished wall just big enough to get lubricant tube through.

I'm curious to see if anyone knows if the cpvc and silicone would adversely react with each other (don't want to cause my pipes to fail faster), or if anyone has ever tried this and seen it help.

Thanks!
-Brian
 

cliffyk

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We had the sane issue, I tracked gown the noisy pipes, removed any clamps, and added foam pipe insulation--had to stuff it in in some locations...

TopClamp.jpg
 

BlueSkyHigh

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We had the sane issue, I tracked gown the noisy pipes, removed any clamps, and added foam pipe insulation--had to stuff it in in some locations...
So do you think it was the clamp-to-pipe interface that was squeaking or something else? I have the same issue but have learned to not hear it just like some people learn to not hear their wives' harping on the honey-do list.
 

briandm

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Unfortunately mine is not a clamp issue (already removed any relevant ones). It is unfortunately just the pipe slipping through the tight hole in the wood floor plate and there's no room for anything to slip in there. There's no way to open up the space around the pipe without damaging or removing the pipe. The only thing I can think of is to use some sort of lubricant
 

Twowaxhack

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Unfortunately mine is not a clamp issue (already removed any relevant ones). It is unfortunately just the pipe slipping through the tight hole in the wood floor plate and there's no room for anything to slip in there. There's no way to open up the space around the pipe without damaging or removing the pipe. The only thing I can think of is to use some sort of lubricant
Don’t use a lubricant unless you want the pipe to fail and flood your home in a year or two
 

Bird Doo Head

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There's a product on the market called Synco Super Lube Synthetic Grease that is compatible with PVC. Perhaps contact them to see if CPVC is compatible.

I've done the foam that Cliffyk mentioned with success on steel conduits. Spray insulating foam also works, but not the window-door type. It's too soft.

Something that might help is cork insulating tape. It is a rubber-cork mix. Parker-Virginia tape is heavy duty and lasts forever. I use it under all pipes that rub and may squeak. You can stretch it to thin it if desired.

For copper pipes,there's another benefit: It is it's dielectric. Copper 2-hole straps are often plated steel. When the pipe slides & the strap's plating wears off, you have steel against copper which will eventually cause galvanic corrosion. Over the years, my house has had several leaks from these corrosion holes. I put a piece of the cork tape on each existing plated strap's belly. Now, I buy only pure copper straps and band iron & skip the hardware store stuff.

Paul
 

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RonAKA

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I'm the unfortunate owner of a house plumbed with cpvc. Every time someone turns on the hot water after it's been off a while (so water and pipes of the hot water line start off cold), I hear creaking in the walls. I know what it is - thermal expansion of the pipes that's extending the pipe down and through the floor plate inside the wall and it's rubbing in the hole ( I cut out a piece of my garage wall and can see it moving about 1/8". It's not just pressing on one side, but rather is in a hole that it seems has no margin or gap on any side.

I have 2 concerns:
1) just the annoying noise
2) I'm aware of the fragility of cpvc and am concerned that this catching rubbing ain't doing it any favors.

I could cut the pipe out, widen the holes, and then replace - but that would be a non-trivial amount of work as it's in a few locations, one of which is a finished wall that would be more difficult to patch. So I was wondering if maybe I could use some sort of lubricant (silicone?) to help it slip through better without catching. It would be a super simple first option to test out. On the finished wall, I might even be able to get by with just a couple small holes in the finished wall just big enough to get lubricant tube through.

I'm curious to see if anyone knows if the cpvc and silicone would adversely react with each other (don't want to cause my pipes to fail faster), or if anyone has ever tried this and seen it help.

Thanks!
-Brian
CPVC has excellent resistance to silicone and most other oils. See this chart:
 

Twowaxhack

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Twowaxhack

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You would think that modern science could develop something that would not attack CPVC but maybe not.
Bottom line is the original poster has cpvc that wasn’t installed correctly.

So the answer is to rip it out and install a piping of choice correctly.

I assure you strapping the pipe too tight or drilling the holes through the framing too small isn’t the only mistake the installer has made.

Cpvc is “ ok “ if it’s installed correctly. Problem is almost no one, especially DIY installers rarely if ever install it correctly. It’s not as DIY friendly as people think.

Spraying things inside finished wall sounds like something out of a cartoon.

Good day gentlemen……
 

RonAKA

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You would think that modern science could develop something that would not attack CPVC but maybe not.
Silicone will not attack the CPVC but may not stay effective for the longer term. There are cable pulling lubricants that are wax based and may be more suitable. One would have to check on specific compatibility with CPVC though.
 
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