PEX (cross-linked polyethylene) pipe should not be installed outside for two reasons: 1) it is not rated by manufacturers for exterior exposure, and 2) the pipe degrades with sunlight exposure. The installation manual for Zurn® PEX pipe states that it “should not be stored or installed where it will be exposed to direct or indirect ultraviolet light (i.e. sunlight).”

    Sunlight deteriorates the molecular structure of PEX, making it brittle and prone to rupture. It should be in a covered location when installed, and even storing the pipe in indirect sunlight until installation is not recommended. The PEX pipe shown above is at an exterior wall of an older home that has been re-piped. The spray-paint coating of the pipe provides some UV-protection, as long as it remains intact, but exterior installation is not approved. 

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Here’s links to a collection of our other blog posts about PLUMBING PIPES:

• Can PEX pipe be connected to a water heater?

• Can I get insurance with PEX piping? 

• How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?

• Can galvanized steel pipe still be used for new water lines in a house? 

• How can I tell if I have cast iron pipes in my house? 

• Why can't a sanitary tee be used for a horizontal-to-horizontal drain pipe connection? 

• What is the difference between green and white sewer drain pipes?

• Is a washing machine drain hose required to be secured at the standpipe?

• What are the abandoned pipes sticking out of the wall in my house?  

• What are the code requirements for plumbing vent terminations?

• What is the difference between water pipe and sewage (waste) pipe? 

• Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water? 

• Is a hot water faucet handle required to be on the left? 

• What is the difference between PVC and ABS plumbing pipe?

• What is the difference between water service pipe and water supply pipe? 

• What are the pipes on my roof? 

• How can I find out what type of water pipe runs underground from the water meter to the house (service pipe)?

• What is a P-trap?

• Why is old galvanized steel water pipe a problem for homebuyers?

• What does polybutylene pipe look like? Why is it a problem? 

• Which water pipes are an insurance problem and possibly uninsurable?

• Can you connect CPVC pipe directly to a gas water heater?  

     Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.