Use of PEX and Push-On Fittings in Unheated Area

[voyager72]

For my summer house - which is unheated and has water pipes that must be drained every year - I want to possibly replace the 60-year old copper lines with PEX and ProBite or SharkBite push-on fittings. Are these materials suitable for an unheated crawl space under the house where the lines are drained in winter and where temperatures might reach zero degrees or below on occasion?

 

[phishfood]

I don't recommend push on type fittings for permanent installations. The Orings can eventually wear and leak, especially when they experience extreme pressure fluctuations.

For your particular situation, I would suggest Uponor PEX with crimp fittings if you intend to DIY, expansion fittings if you will have a professional plumber install the system. The Uponor pipe can handle some expansion from freezing, because it is made to expand and then contract back onto it's expansion fittings. I would install it with a slight pitch toward a drainage point that is then piped to a conveniently located drainage valve. If you also fabricate an attachment to which you can attach an air compressor to charge the system with air, and then quickly release the air pressure through the drain valve, you should be able to achieve a pretty thorough evacuation of the piping.

 

[dino]

You can also heat trace pex