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Building codes guy
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40 Posts
Discussion Starter · #1 ·
Here's something that might bear mentioning.

Many plumbers (and inspectors) are unaware of the PEX manufacturers' requirement that their pipes not be installed in close proximity to sources of heat. Over time, exposure to high heat will make PEX brittle.

I often see PEX right next to can lights, furnace and water heater flues, fireplace vents, B-wall vents, etc. The manufacturers require 6" of clearance to any source of heat, and the manufacturers' association literature requires 6" horizontal clearance and 12" vertical clearance.

You won't find this in the code. But, inspectors are supposed to enforce manufacturers' requirements as well.

It is usually easy to fix, but who wants the hassle!
 

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Master Plumber
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1,069 Posts
From Uponor:
Recessed Lighting
There are two types of recessed lights: Type I.C. (Insulated Ceiling) —
direct contact with thermal insulation and Type Non-I.C. (Non-insulated
Ceiling) — 3-inch minimal clearance with thermal insulation.
• If there is not enough room in the joist cavity to meet the 12-inch
restriction stated by Wirsbo, then insulation is required.
• The insulation must be rated to withstand the temperatures
generated by the fixture.
• All tubing that is within 12 inches of the recessed light must be
insulated with closed-cell polyethylene, polyolefin or other suitable
pipe insulation for 12 inches on either side of the light.
• Insulation is required anytime a UV light source is used; tubing
must be protected for direct UV exposure.
 

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Master Plumber
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1,069 Posts
From Uponor again:

Do not install AQUAPEX tubing within 6 inches of any gas appliance
vents, with the exception of double-wall B-vents (with a minimum
clearance of 1 inch).
I appreciate the heads up OP, but please be careful about promulgating incorrect information on here. Not saying you were. I just hate to see bad info given out.
 

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Plumber Manhattan Beach
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828 Posts
How do you figure that it calls for 18" of hard pipe?

UPC 604.13.2 WATER HEATER CONNECTIONS

PEX-AL-PEX OR PE-AL-PE tubing shall not be installed within the first 18" of of piping connected tot he water heater.

so, in my book, and inspectors minds, pex needs to be installed min 18" from the water heater, so I run my 18" water flex, then 18" in thge wall, tie in with pex. I use hard pipe to make the connection ridgid, I perfer work that last many years, not a wobbly hack job coming out of the wall.

should have just said 18", rather then the way I put it. I added my personal needs
 

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Banned
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8,808 Posts
UPC 604.13.2 WATER HEATER CONNECTIONS

PEX-AL-PEX OR PE-AL-PE tubing shall not be installed within the first 18" of of piping connected tot he water heater.

so, in my book, and inspectors minds, pex needs to be installed min 18" from the water heater, so I run my 18" water flex, then 18" in thge wall, tie in with pex. I use hard pipe to make the connection ridgid, I perfer work that last many years, not a wobbly hack job coming out of the wall.

should have just said 18", rather then the way I put it. I added my personal needs
Thats what mine code tells me also, check it out via code link in my signature,.
 

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Master Plumber
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1,069 Posts
Also for anyone reading this, the amount of heat is relative. Keep in mind that PEX is rated for PRESSURE application at up to 200 degrees.

I cannot find any reference that PEX actually becomes brittle with exposure to higher heat. It may, but unless the OP can source his claim I tend to be fairly skeptical of such a claim.

Running next to furnace duct is perfectly acceptable and no one should worry about it at all.

Here's what Zurn PEX says:

Zurn PEX may be connected directly to
electric water heaters for residential
plumbing applications. Zurn PEX has brass
male and female threaded adapters and
swivel adapters that can be used for this
application.
Zurn PEX must be kept at least 6" away
from the exhaust vent of a gas-fired water
heater. This is easily accomplished by
using flexible water heater connectors.
When the inlet and outlet connections are
well away from the exhaust vent, such
as most heaters with side connections,
Zurn PEX may be connected directly to
the water heater.
Please note that they allow for direct connection to a water heater. No supply connector needed. Uponor has removed all reference to the 18" requirement from their manual. So unless the code requires it, you may be allowed to connect directly to the water heater.
 

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Master Plumber
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1,069 Posts
UPC 604.13.2 WATER HEATER CONNECTIONS

PEX-AL-PEX OR PE-AL-PE tubing shall not be installed within the first 18" of of piping connected tot he water heater.

so, in my book, and inspectors minds, pex needs to be installed min 18" from the water heater, so I run my 18" water flex, then 18" in thge wall, tie in with pex. I use hard pipe to make the connection ridgid, I perfer work that last many years, not a wobbly hack job coming out of the wall.

should have just said 18", rather then the way I put it. I added my personal needs
Gotcha.

My PEX stub outs aren't wobbly but each to his own.
 

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378 Posts
I believe pex has a requirement that it cannot be exposed to sunlight for more than 6 months as well.But it's too late to look it up so don't kill me here.And I believe that includes indirect light say ,from windows .
 

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Master Plumber
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1,069 Posts
Zurn:

IMPORTANT – Zurn PEX:
• should not be stored or installed where it will be exposed to direct or
indirect ultraviolet light (i.e. sunlight).
Question. Do UV rays fill a room that is lit with sunlight? Or are they only present in the direct rays of the sun?
 

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Plumber Manhattan Beach
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828 Posts
Gotcha.

My PEX stub outs aren't wobbly but each to his own.

As we build a forum friendship here, you will find I can be overkill. but I sleep well at night:thumbsup:

Pex is still not allowed here, unless by variance, until 2009, jan.

I installed alot of it in new mexico, many years back. I like solid connections and would never run it right to a fixture, for sure, not right to a water heater. my own deal. like I said, overkill......:) :) :)
 

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Banned
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8,808 Posts
I could be wrong, but I think it has to be direct sunlight, UV rays is what gives you a sunburn, if your in a room with sunlight filled in it, as long as your not directly in it, you won't get a burn, just my theory, so no UV in a indirect way..
 

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Master Plumber
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1,069 Posts
As we build a forum friendship here, you will find I can be overkill. but I sleep well at night:thumbsup:

Pex is still not allowed here, unless by variance, until 2009, jan.

I installed alot of it in new mexico, many years back. I like solid connections and would never run it right to a fixture, for sure, not right to a water heater. my own deal. like I said, overkill......:) :) :)
I sure wasn't trying to bust on ya. The sleeping well at night is a good point.

Tonight on the way home from the job I was talking to my lovely wife on the phone. I was a bit discouraged and asked her "Why do I think every aspect of every job has to be perfect and overkill? Man, why can't I just be like everyone else out there? Just do a decent job and let it go? But no, not me. I can't leave until it's perfect and until I have gone completely overboard with everything I do."

Her answer? "Because you are the best." Made me feel a bit better.

(I had been running T-Stat wires. I don't like fastening T-Stats to sheetrock so I cut some blocking, screwed it in place, and drilled a hole at the right spot for my wire. Each wire is 60" off the floor and 15 1/2" from the door way or the edge of the wall. Anal ain't I?)

So I completely relate to your statement. I just happen to believe I can make my PEX stub outs adequately solid. I usually use 2 USBs from Sioux Chief for my WH stub outs. One on the vertical about 4" down from the 90 and one on the horizontal where it exits the wall. Squeeze 'em down tight and they are rock solid.
 

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Building codes guy
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40 Posts
Discussion Starter · #16 ·
I appreciate the heads up OP, but please be careful about promulgating incorrect information on here. Not saying you were. I just hate to see bad info given out.
The only bad information I gave was not providing proof that PEX can become brittle after long-term exposure to high heat. Brittle might not be the best descriptor. I'm digging for a disc that has a picture that I took a couple years ago of an installation by a woodburning chimney flue pipe...If I can find it I'll post it. The walls were opened up during a remodel, which presented the photo op. Perhaps "brittle" isn't the best word, but it didn't look good, even though the pipe was still holding water.

Per the Plastic Pipe and Fittings Association's PEX Installation Handbook (www.ppfahome.org), the aforementioned 18" water heater rule is correct. Their handbook also gives the 12" vertical/6" horizontal clearance requirement from sources of heat.
 

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Master Plumber
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1,069 Posts
The only bad information I gave was not providing proof that PEX can become brittle after long-term exposure to high heat. Brittle might not be the best descriptor. I'm digging for a disc that has a picture that I took a couple years ago of an installation by a woodburning chimney flue pipe...If I can find it I'll post it. The walls were opened up during a remodel, which presented the photo op. Perhaps "brittle" isn't the best word, but it didn't look good, even though the pipe was still holding water.

Per the Plastic Pipe and Fittings Association's PEX Installation Handbook (www.ppfahome.org), the aforementioned 18" water heater rule is correct. Their handbook also gives the 12" vertical/6" horizontal clearance requirement from sources of heat.
Note that I did not say you gave bad advice. I just warned against it.

Your over all point was very valid. There were some flaws in what you posted. One was the mention of furnaces being a problem, another was your comments were too generalized and incomplete, and the last thing was your claims of it making PEX brittle.

Hey we all make mistakes so don't sweat it man. All I wanted to do was make sure anyone reading this gets their facts straight.

As far as that industry handbook, that's great. But no inspector better turn down my job because of something said in that book. Ever. It better be in the code book or by extension the manufacturer's instructions. But my job will not be turned down over deviance from a relatively obscure third party's materials with wift consequences.

Having said that, the information in that manual is valuable and we should all take a look at it.

BTW, I never said the 18" rule for water heater connections was not valid. I was only saying that at least one manufacturer took out all references to it and at least one other specifically stated it does not apply.

So if one's local code allows it, and if one is using Zurn PEX, you are allowed to connect PEX directly to the water heater if you wish. Doesn't matter what the PPFA says about it. They have no jurisdiction on the matter.

If I am wrong on anything I post feel free to correct me. This ain't about ego for me. It's about accurate information being promulgated.
 

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Building codes guy
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40 Posts
Discussion Starter · #19 ·
There were some flaws in what you posted. One was the mention of furnaces being a problem
I didn't say furnaces were a problem. I said furnace flues, a source of heat that PEX cannot be installed up against. I simply provided the plastic pipe association handbook as a resource, not a be-all, end-all that would override specific manufacturers' installation guidelines.

22, I hope you're as comfortable and understanding when someone passive-aggressively nitpicks your every word as you expect everyone else to be.
 
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