Installing PEX, what constitutes UV exposure which requires protection?

Hi all,

I'm a homeowner & am currently in the planning stages of ripping out my PB plumbing & replacing with Wirsbo Aquapex. Manufacturer states not to expose to direct sunlight for more than 30 days but is vague on what other scenarios require UV protection. I've searched this forum & elsewhere & can't seem to get a definitive answer. So, here are a couple of scenarios that I will encounter in my install.

Piping in basement. This side of the basement is my shop & has two windows & a slew of 2 tube 4ft shoplights. Windows are covered by curtains which completely block the direct sun, but still let light through. These are standard builder grade basement windows at the top of the foundation. The wall they're on is west facing. Most piping will be above the height of the shoplights, but not all of it. Shops lights probably average an hour of use a day. Do I need to UV protect this piping?

Piping, still in basement, but on the other side away from the windows & shoplights. There is some light spillover from the shop side, but not much because there is a wall separating the halves. Currently there is no door in the opening between the two sides but there will be soon. This half is lit by a pair of exposed CFL's in ceiling fixtures. Probably average less than an hour a week use as the space is used for storage. However, this half of the basement will eventually become finished space & the piping will be behind drywall. Let's say I don't get around to finishing it for another year or two. Do I need to UV protect this piping?

Thanks!

-Dave

UV is a "direct light source" so if the sunlight is NOT shining directly on the pipe, it is not being exposed to the rays.

What about all the fluorescent lights? Those are a source of UV as well & some of the pipe will get direct exposure.

I have never heard of them being a strong enough source to require protection, or give a person a tan. Just do not expose it to a tanning booth. As a practical matter, your PB tubing was also affected by UV and if it did not fail because of that, then the PEX will not either if it is installed in the same manner.