Click here to look at this report of a successful lawsuit against a manufacturer of corrugated stainless steel tubing (CSST) for damages resulting from an indirect lightning strike: .

If you’ve ever run black pipe to deliver natural gas to a combustion appliance such as a furnace or water heater, you won’t have any trouble seeing the beauty and convenience of a product that installs much like PEX, but that is used for natural gas and propane. Unfortunately, the very flexibility of the CSST product also appears to be its vulnerability.

Since the corrugated stainless steel material gains flexibility by being thin, it is vulnerable to electrical surges such as those created by lightning. The lightning can melt the CSST and release natural gas into the house where the fuel can reach an explosive concentration quickly. Methane becomes potentially explosive when it is 5% of the atmosphere . . . propane at only 2.1%. (For more on this topic look at The Engineering ToolBox.)

I’ve been following the possible problems with CSST since at least 2007, when N.Y. State code added language to the effect that the flexible piping should be electrically bonded.  Only a few houses that I have been in since that regulation was adopted have complied with it, and this has worried me to some extent.  Now it appears that bonding cannot protect the gas delivery system from nearby lightning strikes.

Remodelers and builders need to be aware of the potential problem with this material and to think carefully about using it in their projects.