I agree with Marc, John and Jim. I would avoid CSST at all costs. Too many fires, deaths and analysis has shown that it was related to CSST. I had a gas line extended in our home a few years ago and our local plumber (long time and well respected in the business) will not touch CSST. He says it has not yet been proven to him to be safe and he does not want to put his clients into a "potential unsafe" situation. He said it might change over time, but he is not ready to bite ... yet. He is staying with black iron. The CSST lobby is alive and well and has the Texas TREC licensing agency wrapped around their fingers as well. TREC has verbiage we have to use that pretty much paints targets on the Texas inspector's back when it relates to CSST. The lobby prevailed with the changes even against other forensic engineering reports and data from Texas Fire Marshals about failures they are very uncomfortable with. One local D/FW inspector is still under a pending $1M lawsuit due to a home fire caused by a lighting strike that had some CSST extensions installed to black iron. Its been ongoing now for nearly 2+ years. For me (as I've noted above) ... I will not have CSST in my home.