PEX water tubing is being stored and installed where it will see direct sunlight for an extended period. What does the code require regarding that exposure?
- APEX may be exposed to sunlight indefinitely, because the chlorine resistance rating printed on the tubing covers ultraviolet exposure as well
- BPEX may be exposed to sunlight if it is coated with a latex primer that blocks ultraviolet light before the wall is closed
- CSunlight has no effect on PEX, and only sustained temperatures above 180 degrees F will shorten the service life of the tubing in a hot water distribution line
- PEX must be protected from ultraviolet exposure, and any exposure is limited to what the manufacturer's installation instructions and listing permit
Where to look it up
https://www.uponor.com/getmedia/3002f54f-d63c-4f3a-807f-70d91f620843/2023-2028-wi-listing-pp-022300004-ptoaafinalp?sitename=USA
Why D is correct
Protect PEX from ultraviolet exposure and follow the limits and installation conditions for the particular product. Chlorine resistance does not establish unlimited sunlight resistance. Do not assume a latex primer alone makes an exposed installation acceptable. Uponor permits certain latex and acrylic paints on AquaPEX as compatible materials, but paint compatibility is not evidence that the coating satisfies UV-exposure requirements. Check the current product instructions, listing and adopted requirements; exposure limits and conditions vary. Source: https://www.uponor.com/getmedia/3002f54f-d63c-4f3a-807f-70d91f620843/2023-2028-wi-listing-pp-022300004-ptoaafinalp?sitename=USA