Is it safe to put a copper gas pipe on the outside of your house?
Interesting - everyone's said No. Regulations are probably different in the USA, but here in the UK it is common practice to use copper piping for gas, both indoors and out. I had a new gas meter fitted by the gas company about 12 years ago, all the new piping is copper, exactly the same as water pipe. Even the pipe that comes out of the ground to the meter is copper.
In the UK copper pipe to EN 1057 is fine for gas installations. Admittedly, most people use something stronger, maybe iron, being less liable to damage than soft copper.
NO copper is to soft, use Black Pipe do not use Galvanized Pipe as the gas could leach out
