Dunno how you folks do it over there cause even though I been there and done some work I still cannot figure out how you folks get things to actually work!!
Down here we run pipes through sleeves or plastic tubes where they pass through concrete to protect the pipe from abrasion and corrosion.
If metal pipes are buried underground we wrape them as well for the full length underground and backfill the trench with clean sand.
Give it a try I am sure it will work properly for you up there as well.
Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians