Direct sunlight is the problem. Do not let the Sun shine directly on the PEX for extended periods. Light through a window that does not strike the piping directly should not be a problem. UV damage to PEX, if it occurs, is permament.

I submit that rather than asking opinions, which may or may not be based on experience or fact since you didn't name the EXACT product, on an internet forum you should be in contact with the manufacturer of that specific PEX and asking then for their position on the subject.

Quote: "Direct sunlight is the problem. Do not let the Sun shine directly on the PEX for extended periods. Light through a window that does not strike the piping directly should not be a problem"

That is not true!!!!!

All sources of UV light whether direct or reflected indirect sunlight, incandescent light or even a flashlight or the arc from a welder are detrimental to PEX.

As our local inspector likes to put it, "If you can see the pipe without opening a door, removing a cover, or turning a light on, the PEX is not installed correctly, and does not pass code".

When transporting PEX tubing to a jobsite it must remain in the cardboard box and only be taken out of the box at the actual time of installation. If an inspector comes on a jobsite and sees PEX out of the box and not being used he/she has the right to insist that all of that PEX be cut into 3ft lenghts and discarded as damaged pipe.

When PEX us run through open stub bays in a basement the idividual PEX tubes should be covered with a vinyl sleeve, or the underside of the stud bay should be covered with black plastic. Some codes require that the basement windows be covered with a UV protectant film.

Quoting directly from the Zurn Pipe Products PEX installation handbook..PG 16-

Doors are usually used to cover the manifolds. These may be made by a carpenter to match the other cabinets in the house or Zurn sells a plastic access panel that can be used. Zurn access panels come with a frame that can be fastened to the sheetrock with adhesive or screws for easy installation. The panels snap into place and are essentially flush with the sheetrock.

Over the last two years or so many ppl have ridiculed me for saying that PEX is more difficult to run than other materials because it requires much more attention to detail, and no doubt many of you are ready to jump on me here as well, but then I have to be more cautious because when I install it, it is warranted...on the other hand, there is a disclaimer in the manufacturers warranties that says that all warranties whether written or implied are null and void unless the PEX is installed by a licenced plumber.

So what do I do about all the PEX in the basement which was installed at the modular factory (above the floor joists), transported here, lifted on a crane and set on the foundation?

I can replace the couple inches that were sticking out of the wall in the back of the (uncovered) vanity, and I can throw out the two 5-ft pieces I cut off my cousin's spool but I can't replace all the PEX in the house. If the damage is instantaneous, then any PEX in the 2 upstairs modules that might have been exposed during build/transport/set would have to be replaced too. How can the modular home companies use PEX if it can't be exposed to sunlight at all? Even if they covered it during transport (I don't remember), any covering was stripped off once they lifted it up and before they set the modules in place - I have pictures of the back half of my house (master bathroom and general bath) on a bright June day with exposed PEX on the underside of the module.

Home Depot displays their PEX on open shelves - not in direct sunlight (in my local store) but fluorescent lighting.

First off, let me calm your fears a bit. The effects of UV light are not immediate. All plastic pipe is deteriorated to some degree by continued exposure to UV light at all levels. The extent of the damage is proportional to both the intensity and the duration of the exposure. The more pronounced the exposure the more it tends to shorten the anticipated service life of the products, however even in a worst case scenario it would probably be 10 to 15 yrs before any real problems start to manifest themselves. One of the first signs that the pipe has been compromised by exposure to UV light is a dull chalky appearance on the exterior of the pipe.

Now in regards to Home Depot displaying the product open on the shelves. If one were to diligently go through a Home Depot, Lowes or any other home supply center he/she could write a book about how materials are handled improperly, but then it goes back to what my daddy used to say. If the ppl handling that stock knew the trades they would not be working in a hardware store, and if you pay peanuts you have to expect to hire monkeys.

OK, I just checked the basement - I remembered that most of the pipe down there was white semi-transparent since I had to trace out the toilet line to the powder room to determine which stub out under there was cold and which hot. The trunk runs along the east wall, right along the sill plate, and I thought that was installed at the factory. Goes up to kitchen sink, over the top of the small window in the foundation, and over to the SE corner where it goes to the upper story modules.

Manufacturer is WIRSBO, at least if it's the same as what local plumber ran to our hot water heater. DH says the same plumber did *all* the PEX in the basement, including that running along the sill plate, not just the lines running to PR and water heater, well. DH had covered the hot water line (and some of the cold) running along the perimeter walls with gray split insulation.

So, as long as the red and blue PEX used in the upstairs bathroom wasn't exposed to UV for more than 30 days or so at the modular factory, it should be OK.

I will go buy new for the PR and throw out what I got from my cousin since I don't know where that was stored or how it was handled. He says it was stored in the basement, I guess I do remember him pulling it out of a corner, forget what he went in the garage for the other day, he was grabbing stuff for me as we were leaving.

And how much do I have to worry about the little bit that was exposed in the master bath vanity with no countertop across the room from an east-facing window (not directly, offset with end of vanity just to side of window)? Also might have gotten a little sun from south window in BR since we leave the bathroom door open all the time, but indirect since sun doesn't really get high enough to shine directly into the top of the 34" high vanity.

But where can I buy 5 ft of each color that I know was stored correctly? I only mentioned HD b/c they must be storing it improperly, don't want to buy it there (in clear plastic, not cardboard boxes) even if they sell it by the foot.

I will call the plumber who did the onsite work about the broken clips in the basement, ask about covering the stuff he installed, maybe he has some color-coded stuff that's been stored properly. I wanted to hire someone to run the lines for the PR when we finished the master bath, but cousin had this stuff and DH really wanted to get a sink in the PR right away (of course *he's* not the one doing any home improvements), so I figured I could do this for him NOW and not wait til I'm done with tiling in the master bath.

How long does it take to develop the chalky appearance?

Thanks for all your help.

Just found a large roll of PEX for my current remodel sitting outside uncovered. It's been there since yesterday morning...On North side of house which is better than nothing...there is plenty of "reflected" UV light though...I just discovered it late this afternoon (does get a small amount of direct evening sun....Was delivered yesterday for plumber who was intending to start today....but plans changed. From what I gather here, I don't need to be overly concerned? It would truly su*k if the pipe failed any sooner than it's typical life-span as it will be buried in concrete.