[masraum]

PEX can certainly be buried. I guess the only question then is PVC > PEX > PVC, which I assume is "OK" but not ideal.


https://www.sharkbite.com/us/en/resources/blog/new-build-remodels/piping-systems-comparison-education/10-facts-about-pex-pipe-you-need-to-know

Can you bury PEX?

Yes, you can bury SharkBite PEX-a and PEX-b pipe in most applications, as it’s approved to AWWA C904, which covers PEX pipe in regard to burial. Be sure to check with local, city or state codes to see if the pipe needs to have sleeves or any type of protective burial for your area. PEX pipe can be used as a service line based on its corrosion resistance to soil and water, its long life and its oxidative resistance.

Our PEX pipe is not suitable for use in areas where the soil is or may become contaminated, including soil used for backfilling. Soil used for backfilling must be free of rocks, debris or any sharp object that may cause damage to the fitting or pipe through impact or abrasion.

It's also important to note certain fittings must be wrapped for underground burial, so if you’re installing any PEX connections underground, check to see if you’ll need silicone tape to wrap the fitting.