I felt compelled to register in order to post after reading this thread with much interest. I'm not an inspector but rather a homeowner who has been poring over information concerning csst and electrical arcing after having two perforated (Counterstrike) gas lines in my basement in the past week. The first leak was detected within 30 minutes of the replacement (by a licensed electrician) of a supposedly bad GFCI breaker with a non-GFCI breaker that was controlling the basement electricity. The perforated csst line (image below) had been in direct contact with a metal duct at the point of perforation. Neither the electrician or the plumber made any connection to the perforation and a potential electrical problem. Click to Enlarge 35.7 KB The second leak (on a different line, this one mounted directly to a metal duct) occurred about a week later. After this (and armed with internet knowledge) we went looking for and found the source of the electricity...a stripped electrical wire pulled tight against a duct. The GFCI breaker wasn't bad, it was tripping because of the electrical short. Our GC (new construction house) still seems incredulous that the gas lines could be perforated by arcing from duct work contacting a live wire. We are still trying to gather information and consult our own inspectors to determine if any codes were violated with the installation. Specifically whether electrical wires and/or gas lines should be contacting the ducts. Am I understanding correctly from reading this thread that contact of a csst line with metal duct is quite probably perfectly acceptable? NY is the only specific example I have foundwhere code prohibits contact of csst with metal ductwork (http://www.dos.state.ny.us/code/csst.htm). Thanks for your consideration. Jody
