I welded mine up using 2" thin walled Square Tubing. Yes you can drive a truck on it, but it looks really sharp. I think it was only $80 worth of steel from the local yard and I had 10' of extra. If I had to do it again, I might go with 1.5" but I would still go with the square tubing. I'd...
If it were me I would stay outside (although, with proper fitting pipe and a pressure test you can be sure of no leaks you would be fine inside). I would measure the trench length and contact the gas company and ask for 2 steel to plastic risers and have them use 3/4" MDPE plastic pipe to...