Unfortunately, for the most part, PEX tubing is susceptible to direct UV light. When exposed to direct UV light, you risk the pipe becoming brittle. Keep in mind, different manufactures of PEX may have different ratings based on the length of time it is exposed to UV light. They do, however, put in UV stabilizers in the tubing to give it some limited protection (in days). It is best to inquire with the manufacture to see what their warranty policy is on their PEX tubing if exposed to UV light.
– Jerry T.
Director of Sales – Plumbing