Is it OK to use copper line instead of cast iron around a base board when extending a gas line for a stove? I am very concerned about this passing inspection in Denton Co. in Texas.

Actually it's not "cast iron" that's used for gas lines. It's "black iron". Home Depot will cut and thread custom lengths.

Corragated flexible gas line is available.

Typically copper tubing for gas has to be "tin lined", but it does depend on the impurities in the fuel. The fittings need to be compression.

Copper has a problem, in that it can easily be mistaken for a water line and that would not be good.

You never really mentioned how far the extension is goiing to be. I believe the National Fuel Gas code can be read online. See the Sticky in the electrical section.

Since everyone has specific requirements, it's best to take this up with the AHJ (Authority Having Jurisdiction).

Hi confused...

Are you on natural gas or propane? If natural gas stick with black iron pipe as KISS mentioned. If it is propane (LP gas) gas then can stick with copper tubing as long as you use a flaring tool and flare fittings.

Otherwise, as mentioned above, you might also use a corrugated flexible gas line, but I would call and ask the local gas inspector before doing that as some states/towns/cities do not approve of these connectors.

Let us know if need more info. It is probably best in this case to call local inspector. They don't want to come back to reinspect any more than you want them, too... :)

Good luck...

MARK