Inspecting PEX for potential problems

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mrbob

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My new house uses PEX everywhere. I'm not a plumber and have never dealt with PEX, but I've been reading and learning as much as I can. Unfortunately, the builder is dealing with the plumber, so I can't personally select a good plumber or talk with the plumber.

It would be really helpful if you could give me some advice on inspecting the installation, so I can catch potential problems before they are sealed in the walls. I've read about crimp quality, but so far, it looks like this plumber only uses plastic compression fittings. I haven't seen any crimps yet. I've also read about being wary of pipe damage.

This photo shows a Delta shower/tub valve and a toilet line. From the photo, can you tell anything about this plumbing, either about the pipe used or the fittings? What should I be looking at/for?

bathroom.jpg

I welcome any observations, suggestions, or comments. Thank you very much!
 

SHEPLMBR

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Leave the inspection to the professionals as you do not know what you are looking at. This is expansion pex. It does not use crimp rings. This method gives you full flow. Read up on it.
 

mrbob

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Thank you for the quick reply. That's already a big help. I've read about PEX-A and expansion fittings, but never seen one in the wild. :)

I appreciate your comment about trusting the pros. Most of them are great and most times, they do awesome work. I'm just trying to get the odds a bit further in my favor.

For electrical, they run wires through metal studs with commercial grommets. This plumber is using some sort of expansion foam where pipes go through metal studs. I'm guessing that the pipes will move slightly when the water turns on and off. Is that OK?
 

SHEPLMBR

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Thank you for the quick reply. That's already a big help. I've read about PEX-A and expansion fittings, but never seen one in the wild. :)

I appreciate your comment about trusting the pros. Most of them are great and most times, they do awesome work. I'm just trying to get the odds a bit further in my favor.

For electrical, they run wires through metal studs with commercial grommets. This plumber is using some sort of expansion foam where pipes go through metal studs. I'm guessing that the pipes will move slightly when the water turns on and off. Is that OK?
It should be fine. But in the end it is left to the inspectors.
 

JG plumbing

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I would not recommend the expansion foam as a buffer. Your right the pipe is meant to move. In my opinion the foam isn't great for that. Your picture isn't great. I can't really see the "system" they are using.

But the pex is the best quality of the pex's. Although the fittings aren't the best choice.
 

mrbob

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Yes, this is new single-family construction and the county inspectors will be there a few times.

Where could I learn what is included in a plumbing inspection? Is it reasonable to expect that they will look at every fitting and every place pipe passes through something?
 

FishScreener

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The foam won’t hurt the PEX. But, if I were doing the inspection I would be concerned that the foam didn’t keep the PEX from coming into direct contact with the metal studs. How is it being held off while the foam cures?

Looking at the commercial installation manual I found:
It is possible during commercial construction that metal studs may
be utilized. Protective sleeves or bushings should be used when penetrating metal studs. Sleeves and bushings are not required when penetrating ordinary wood or particle board if the holes are at least 1/8” larger than the tube size and tube movement is not restricted.

It isn’t in the residential installation guide, because residential in the US rarely utilizes metal studs. Based on that I would fail his plumbing inspection, for not complying with the manufacturers installation instructions.

I would contact the County, and ask them about it. You just don’t want to let your builder know.
 
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SHEPLMBR

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The foam won’t hurt the PEX. But, if I were doing the inspection I would be concerned that the foam didn’t keep the PEX from coming into direct contact with the metal studs. How is it being held off while the foam cures?

Looking at the commercial installation manual I found:
It is possible during commercial construction that metal studs may
be utilized. Protective sleeves or bushings should be used when penetrating metal studs. Sleeves and bushings are not required when penetrating ordinary wood or particle board if the holes are at least 1/8” larger than the tube size and tube movement is not restricted.

It isn’t in the residential installation guide, because residential in the US rarely utilizes metal studs. Based on that I would fail his plumbing inspection, for not complying with the manufacturers installation instructions.

I would contact the County, and ask them about it. You just don’t want to let your builder know.
That being said, it does not look like ordinary foam but it appears to be fire protectant foam. I could be wrong.
 

JG plumbing

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It kind of looks like they did use some kind of grommet under the foam. But the picture isn't good.

If they used plastic grommets under the foam and just used the foam as a redundancy its fine. Just get a leak test before they close up the walls.
 

Mitchell-DIY-Guy

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No, but they should ask for a leak test. That doesn't mean they will.
Well I don’t know the specific standards in terms of pressures or how long they leave it there, I do know that a new construction around here what they do upon completion is pressurize the entire supply system, with a gauge attached, and leave it for several days.

They also fill all the fixtures, while the drain system is not yet connected to the city sewers and is capped off at the outside of the house.

In the houses I have seen constructed where this is done this pressurized supply and capped off drain set up is left for many days... then they come back and see if it has passed the test if if it has not find the problem and fix it and do it again.
 

JG plumbing

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Generally you pressurize for 15 min. The inspector should ask to look at the gauge upon arrival, then inspect, then check it when he leaves.
 

TomFOhio

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We use to cap all the drain lines off and then fill the system with water in the pipe going out the roof. I
always like this better than air, but sometimes you don't have water available. We use to put 90lbs
pressure on the water lines with a guage for the plumbing inspector to see.
 

Mitchell-DIY-Guy

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Generally you pressurize for 15 min. The inspector should ask to look at the gauge upon arrival, then inspect, then check it when he leaves.
I suppose that would be possible around here, if the plumbers and the inspectors had free reign on their schedules! Turns out they don't. A plumber waiting on an inspector isn't plumbing, and an inspector has a long list of things to inspect, and has no time or patience to wait around.

Thus these things are left in place for quite some time. How long? Dunno. But way longer than 15 minutes...more like a day or so.

I think it's a coordinated dance with the plumbers and inspectors arranged by the builders.
 

JG plumbing

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I suppose that would be possible around here, if the plumbers and the inspectors had free reign on their schedules! Turns out they don't. A plumber waiting on an inspector isn't plumbing, and an inspector has a long list of things to inspect, and has no time or patience to wait around.

Thus these things are left in place for quite some time. How long? Dunno. But way longer than 15 minutes...more like a day or so.

I think it's a coordinated dance with the plumbers and inspectors arranged by the builders.
Correct.
I guess I'm just saying the code requires 15 min.
 

mrbob

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Thank you all for your comments and help.

The plumbing fixtures won't be installed until long after drywall is up, so it seems that the pressure test has to happen at the end of construction, after all of the pipe is concealed.

If that's the case, then wouldn't any required repair be really difficult, both in finding the issue and ripping open walls to fix it?

For you good plumbers, when installing PEX, how often do you find something that needs fixing with a pressure test?
 
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