04/21/2022
This article details a potential hazard related to Flexible, Yellow, Corrugated Stainless Steel Tubing (CSST) Gas Lines within your home. It also describes a safety hazard and code changes due to the history of house fires associated with CSST when lightning strikes nearby, or worse yet, the home itself.
The risk is tremendously reduced when CSST flexible gas lines are “bonded “ (BONDED DEFINED: Connected with wiring to take electrical current away from CSST flexible gas lines in the event of a lightening-strike on or near the home). Lightning-strikes have a documented history of creating holes in CSST gas lines, allowing the gas to escape and dramatically increasing the risk of gas-fueled fires in the home. Confined gas fumes that are in a closed room or an unoccupied home can lead to an explosion.
Connecticut Building Code has allowed CSST gas lines since the 1990’s. Building Codes requiring bonding of CSST flexible gas lines came into practice no earlier than 2007. This code came in as a response to damage to flexible gas lines and fires in homes struck by lightning. As you can see, there is a significant multi-year gap in which Building Codes did not require proper bonding of flexible gas lines. Building Codes, including Plumbing & Electrical Codes were updated based on the growing incidents of house fires.
Homes built with CSST flexible gas Lines before the Building Code required bonding were built correctly to the Building Code at the time they were built. BUT that does not mean they are safe. These homes may, or may not have bonded gas lines. Only an inspection will determine if the gas lines are safely bonded as required by today’s Building, Plumbing & Electrical Codes.
If you own a home that has CSST flexible yellow gas lines and was built prior to 2007, this fire-risk may exist in your home. Most homes have gas lines in their attic, walls & basements. CSST flexible gas lines in the attic are a prime candidate for damage from lightning strikes. Especially if they are not protected with Bonding to ensure electrical energy is carried away from the pipe (versus carried by the pipe). The home needs to be inspected, and proper bonding (if not already present) must be installed to yellow flexible gas lines to help protect the home in the event of a lightning strike. Many fire experts are confident that a lightning strike’s electrical-energy can run through the electrical wiring in a house, then jump (or arc) onto CSST gas lines where it creates holes into the tubes, releasing gas & possibly creating a gas-fueled fire and / or explosion.
There are documented incidents where severe lightning has struck homes. A lightning strike to a steel chimney cap, can extend into the house. For instance; Lightning can enter the home through a metal chimney cap extending the electrical-energy through copper electrical wiring, copper water piping, the wooden structure itself and, if available and not protected, the flexible CSST gas line. Electricity will take the easiest path or the path of least resistance. If a lightning strike is large or close enough, the electrical current can jump between products in search of the ground.
In some areas, as of 2015 Home Inspectors became required to notify their clients (in writing & on the inspection form) of the presence of CSST gas lines that do not have proper bonding.
If you own a home built since 1990, your home may have unbonded flexible gas lines. Many homes have gas lines in their attic and buried in walls. If your concerned, the home needs to be inspected, and (if not present) proper bonding must be installed to CSST gas lines, to help protect the home in the event of a lightning strike.
Example pictures of damage CSST piping caused by lightning.
