Q. A client wants to install an outdoor gas fireplace. The most logical route for the gas supply extends from a roof-mounted furnace 60 feet along an exterior parapet wall and then down. Are there any requirements for lightning protection in such an exposed installation?

A.Mike Casey, a plumber licensed in Connecticut and California and co-author of Code Check Plumbing, responds: While there may be local requirements for lightning protection, there are none in either the 2006 IRC or the 2006 Uniform Plumbing Code. As always, consult your local building department for specific questions regarding gas piping installation, which will need a plumbing permit and should be performed by a licensed plumbing contractor or gas-fitter.

In general, exterior gas piping should be galvanized steel and installed a minimum of 3 1/2 inches above grade (if buried, the piping must be corrosion-protected). In addition, pipe sizing rules are very specific and depend on the input rating (in Btu/hour) of the appliance. That means there may be limitations on connecting to the existing furnace pipe, depending on the input rating of that appliance, the size of the pipe feeding it, and the input rating of the proposed gas fireplace.