Short sections of non-oxygen barrier PEX okay in baseboard system?

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Radio Flyer

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I have water baseboard heat, and the wife has had enough of the PEX in the second-story floors popping and ticking as it expands each time there's a call for heat. We’re planning for new carpet, so I think I’ll bite the bullet and replace all the PEX with PEX-AL-PEX by cutting access channels in the subfloor. Hoping I won’t regret this. Any advice is appreciated.

The end of each baseboard radiator is connected with a sweated elbow and a crimped-on 10-inch vertical section of non-oxygen barrier PEX. (The tubing below the floors is oxygen barrier, which is what I’m planning to replace with PEX-AL-PEX.) So in a total run of 200 ft., about 12 ft. is currently non-oxygen barrier.

Question: Do I need to replace those short pieces to avoid oxygen in the system, or will that little amount not matter? If I need to replace it, I would want to use a short section of standard oxygen barrier PEX to avoid sweating on new fittings, right? I would then connect to the PEX-AL-PEX below the floor with compression (PEX-AL-PEX side) and clamped barb fittings (PEX side). Thanks!
 

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Here's a photo of one of the radiator ends with the non-oxygen barrier PEX coming down from the elbow. (Beside the point, but I'll be shortening this one.)

PXL_20210101_200241647.jpg
 

Radio Flyer

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Hold the phone. Maybe it is oxygen barrier after all. I'll have to study the label.

In other news, I just discovered I have open joists. Maybe that will simplify changing to PEX-AL-PEX?

PXL_20210101_222200928.jpg
PXL_20210101_220134124.jpg
PXL_20210101_220154261.jpg
 
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Radio Flyer

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Just a quick follow-up.

All the PEX for the baseboard heat was indeed oxygen-barrier. It was just two slightly different colors, and one type wasn't as shiny.

As shown in the photos, the PEX is strapped directly to the floor trusses, which is COMPLETELY WRONG. This is the source of all the squeaking. In fact, my entire floor squeaks, both in summer and winter, not because of loose nails or tight gaps, but because of wood-to-PEX contact below the subfloor.

My plan is to remove the yellow plastic strapping and install short pieces of foam pipe insulation wherever the PEX rests on wood in order to isolate the movement and prevent the squeaking. (I've also heard that short sheet metal sleeves can be used, but that sounds more difficult and costly.)

This is going to involve cutting and repairing lots of access holes in the subfloor, so I'm not especially happy about it. It's got to be done, though. The squeaking is driving us crazy!
 

Reach4

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In fact, my entire floor squeaks, both in summer and winter, not because of loose nails or tight gaps, but because of wood-to-PEX contact below the subfloor.
That sounds weird to me. Are you pretty sure about that? Maybe try your plan on a small area to see if that gets rid of one squeak point.

I have no relevant experience.
 

Tuttles Revenge

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Oxygen barrier is required if you have any steel in your heating system.

But it appears you've found your problem and solution.

I would insulate every inch of that tubing too, or you're loosing a lot of heat in spaces that aren't necesarily needing it.
 

Radio Flyer

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That sounds weird to me. Are you pretty sure about that? Maybe try your plan on a small area to see if that gets rid of one squeak point.

I have no relevant experience.
Yeah, it seemed strange to me, too. I have cut some access holes already, and if you reach in and hold on to the PEX, the squeaks in the floor go away. Crazy!
 

Radio Flyer

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Oxygen barrier is required if you have any steel in your heating system.

But it appears you've found your problem and solution.

I would insulate every inch of that tubing too, or you're loosing a lot of heat in spaces that aren't necesarily needing it.
Thanks. Do I need to insulate the PEX between the first and second floors? I kind of assumed that having the hot PEX between floors was sort of like a heated floor element and that the heat would just make its way into the level above. Does that sound right? Insulating all of it would be a much bigger job, I fear.
 

Dustbunny

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Plastic wire loom or spiral wrap would make the pipe quiet if you don't want to use insulation. If your heat works well then I wouldn't insulate all of it.
 

jadnashua

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Leaking heat from the PEX between floors may not need to be insulated as it's going into the structure. If it was going through areas that didn't have any insulation to the outside, that would be a different story.
 
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Tuttles Revenge

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I agree with the above 2 posts.. No need to insulate if the heat is just heating the house.. It could adversely affect zones if you had them, or it can mess with thermostats if the verticals pass through the wall where the T-stat is.. Ask me how I know this! UGH. i didint
 

Fitter30

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Look like the subfloor to joists doesn't have have any construction adhesive to cut down on floor squeaks. Pex tubing on wood not to sure that it would squeak. Noisy baseboards a expansion joint would help.
 

John Gayewski

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I don't think adding a scrap of insulation about 3 inches long at the fastening points you have pictured would hurt anything and I do think it would help with the sound.

Make sure what your describing is actually being caused by the pex. The way they have it fastened to the wood does look like an odd method that could cause noise. Not really sure how that happens when the heat is off in the summer.
 

Radio Flyer

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I don't think adding a scrap of insulation about 3 inches long at the fastening points you have pictured would hurt anything and I do think it would help with the sound.

Make sure what your describing is actually being caused by the pex. The way they have it fastened to the wood does look like an odd method that could cause noise. Not really sure how that happens when the heat is off in the summer.
Thanks, everyone!

I think the squeaks when the heat is off are coming from very minor flexing in the floor joists. It's tiny, but enough to create a squeak between the PEX and wood.

I like dustbunny's idea of using wire loom rather than foam pipe insulation. That might be cheaper and easier to install in place. It might also be more durable, right?

I wonder, though, Could wire loom create new squeaks, or popping or "bumping" sounds when the zone calls for heat?
 

Dustbunny

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I just installed half a mile of pex for heat and the wire loom and spiral wrap Do Not make noise. The only noises I'm having are where the pex touches wood or itsself.

I bought a bulk roll...a hundred feet or so to get the price down. Have old vehicles to use it on.
 
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