Had NG plumbed into the garage 6 years ago,nice having a warm garage to work
in!
Do yourself a big,big favour.
Dig a decent trench and lay in 4" conduit or weeping tile FIRST ! Then pull
the approved gas line(yellow palstic up here) through. While your at it
pull some Bell quad,2 or 3 circuits.Good for phone and alarm circuits.
Where the plastic terminates inside, transition to black iron pipe. Put a
Tee here,for future expansion to the gas BBQ and put extras Tees next to the
furnace and the final termination. Again for 'future' uses. You will need
them...glad I did it.

Oh yeah, when you backfill the trench,lots of gravell first, then a layer of
1x6 PT fence boards then dirt.Boards will warn you when you dig in that
area.


Jay