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Unbonded Corrugated Stainless Steel Tubing (CSST) Gas Lines And     The Risk Of Lightning-Strike Fires

Lightning strike

Image Source:,

 CSST Gas Line   Click On Photo To: View This Product, See Details, or Buy Directly From

This article details a potential hazard related to Flexible, Yellow, Corrugated Stainless Steel Tubing (CSST) Gas Lines within your home.  It also describes a history of house fires associated with CSST when lightning strikes nearby, or worse yet the home itself.

On A Side Note:  We also have an article about Power Surges resulting from lighting striking nearby, or the home itself.

Click Here To Our Power Surges Article: Power Surges — Damage Caused, and Ways To Prevent Damage


The risk is tremendously reduced when CSST flexible gas lines are “bonded“.  BONDED DEFINED:  Connected With Wiring To Take Electrical Current Away From CSST 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 fire or explosion in the home.

Click Here To See A Hole Created In A CSST Gas Line Due To Lightning Strike:

 Hole In Flexible Gas Line Due To Lighting Strike

Texas Building Code has allowed CSST gas lines since the 1990’s.  Building Codes requiring bonding came into practice no earlier than 2007 (in response to damage to flexible gas lines and fires in homes struck by lightning).   That created a multi-year gap in which Building Codes did not require proper bonding of flexible gas lines.  Building Codes were updated based on incidents of house fires.

Homes built with CSST Gas Lines before Building Code required bonding were built correctly to Building Code at the time they were built.  BUT that does not mean they are safe.  They 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 Code.

If you own a home that has flexible yellow gas lines and was built prior to 2007, this fire-risk may exist to your home.  Most homes have gas lines in their attic.  This makes them a prime candidate for damage from lightning strikes if they are not protected with Bonding to ensure electrical energy is carried away from the pope (versus carried by the pipe).   The home needs to be inspected, and proper bonding (if not already present) be installed to yellow flexible gas lines, to help protect the home in the event of a lightning strike.

A north Texas area house had a severe lightning strike to the steel chimney cap, and then into the house.   Lightning entered the house through the metal chimney cap (2 quarter-size holes were melted in the chimney cap).  After striking the metal cap, electrical-energy  was carried along: Corrugated Steel Gas Tubing gas lines, Copper electrical wiring, Copper water piping, and the Wooden structure itself.  The home experienced: broken drywall, burned electrical-wiring insulation, damaged copper water piping, and multiple feet of damaged CSST gas tubing.   **

On Sept. 1, 2015 An Update Occurred To The Texas Home Inspection Report (REI 7–5)

Beginning on Sept. 1, 2015 Home Inspectors became required to notify their clients (in writing & on the 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.  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.

Gas Coming To Your Home

Underground gas lines are polyethylene.  They are engineered and certified for underground gas lines installation.  These lines are made in many sizes, from quite large to residential-service lines going to individual homes.

Beyond The Gas Meter, Metal Gas Lines Are Installed Within The Home

Click Here To See An Image Depicting Flexible Gas Line Bonding For A Home:  CSST Bonding Diagram For Entire Home

Click Here To See An Image Depicting Bonded Gas Pipe:  Diagram Of Bonded Gas Line

Click Here To See A Photo Of A Bonded Gas Pipe: Photo Of Bonded CSST Gas Line

For many years (and still today in some locations) metal gas lines installed were rigid black steel (also known as black iron).  Click Here To See Rigid Metal Gas Pipe: Photo Of Rigid Metal Gas Pipe

Corrugated Stainless Steel Tubing (CSST) for gas lines has been allowed in Texas since the 1990’s.  Flexible gas lines are used to pipe gas throughout the home to gas: furnaces, water heaters and gas appliances in most newer homes.  CSST is found in millions of homes across America.

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.

The dielectric yellow jacket is believed to actually increase the problem.  In response, some manufacturers of flexible gas line now have black coated versions that are more resistant to lightening strikes.

A Newer Version Of CSST That Is Reported To Be More Resistant To Lighting Strike Damage

TracPipe® CounterStrike® is a patented CSST innovation based on our existing TracPipe® CounterStrike® flixible gas line product.  It is engineered to significantly decrease the potential for lightning-induced damage to fuel gas piping systems. **

Click On Photo To: View TracPipe Flexible Gas Line, See Details, or Buy Directly From

This Verbiage Is From The Manufacturer: “TracPipe® CounterStrike® is a patented CSST innovation that is engineered to significantly decrease the potential for lightning induced damage to fuel gas piping systems. TracPipe® CounterStrike®has been designed with a proprietary jacket material in place of the standard yellow jacket. This black jacket has energy dissipating properties that will help protect the TracPipe® CounterStrike® stainless steel pressure liner as well as other fuel gas system components if the TracPipe® CounterStrike® becomes energized due to lightning.”

** NOTE: This is not an endorsement of this product by Al’s Plumbing, Heating & A/C — only because we have no direct knowledge of all flexible gas line products available.  This information is provided only as a courtesy to our readers.

This NBC / DFW Channel 5 Newscast & Article describe homeowners’ first-hand experience with a fire caused by a lightening-strike to their newly-built Lubbock, TX home.  The fire investigation stated the lightning-strike appeared to have caused punctures in the gas lines in the attic — setting the home on fire and resulting in the death of their son.

NBC Channel 5 March 18, 2014 News Article about: A Lightning Strike & Fire In New Home In Lubbock, TX

Click Here To See A Hole In CSST Gas Line Due To An Electrical Strike:  Hole In CSST Due To Lighting Strike

NOTE: In this lawsuit, there may have been unwise building practices that contributed to the fire.  Flexible gas lines should not be installed near electrical wiring, as the wiring is highly prone to carry electrical-energy from a lightning strike.  To a lesser degree, CSST should also not be near copper water pipes.  Most new homes today use plastic water pipes that don’t have capacity to carry electrical-energy.  Also, no water lines are likely to be in an attic due to possible freeze damage.

Click Here to see a Texas home with CSST intermingled with electrical wiring (not the Lubbock home in the article above):  CSST Gas Line Intermingled With Electrical Wiring.

There are many documented fire inspections where it was believed a lightning-strike caused damage to unbonded CSST, resulting in gas-fueled fire damage.  In response, CSST manufacturers developed electrical bonding requirements staring as soon as 2007.  Their testing shows bonding will largely mitigate the risk for only “indirect” lightning strikes (those that do not hit the home).   Yellow flexible gas lines were used in the tests.

CSST has been installed in Texas since the 1990’s. The bonding requirement did not go into effect until 2007 or later.  This leaves a possibility (perhaps probability) that homes without properly bonded flexible gas line can be anywhere in Texas.

Electrical Bonding Must Be Present In Homes With CSST Gas Lines — To Reduce The Risk Of Fire or Explosion Resulting From Damaged Gas Lines In The Event Of A Lightning-Strike 

CSST must be bonded to reduce the risk of damage due to a lightning strike on the home.  The most common issue that home inspectors find is the CSST system is not properly bonded.

When this type of gas-distribution system is installed, without being properly bonded to current standards, there is an increased risk for damage from a lightning strike.  Damaged line can leak gas, causing a fire and / or explosion.  All manufacturers of CSST began implementing Specific Bonding Requirements as soon as 2007.

What about existing homes?  Building-Codes have something called ‘grandfathering’.   This means when something was installed in compliance to Building-Codes at the time of the installation — it is deemed correctly installed moving forward in time, even if Building-Codes change significantly.

If CSST was installed (in compliance to code) before CSST manufacturer had special requirements for bonding, that installation still meets code today.   A Home Inspector will (or must) specify the need for a safety-upgrade based on today’s Building-Codes and Safety-Practices.  **  This Should Not Be Confused With UnBonded CSST Gas Line Being Safe — Only That It Met Building Code At The Time It Was Installed.

** Source:

Proper CSST Bonding ***

Click Here To See An Image Depicting Bonded Gas Pipe:  Diagram Of Bonded Gas Pipe

Click Here To See A Photo Of A Bonded Gas Pipe: Photo Of Bonded CSST Gas Pipe

CSST Bond Wires or Clamps Shall NEVER Be Connected to:  ***

  • Natural gas meters or facilities.
  • A ground that is independent of the electrical service grounding system.
  • The corrugated stainless steel portion of the pipe.  Clamps must be attached to: the brass fitting, steel manifold, or other rigid customer-owned pipe).

CSST bond wires or clamps shall ALWAYS be connected to: ***

  • Customer piping — as close to the natural gas meter as practical.
  • A CSST brass fitting, a customer-owned steel manifold or rigid pipe component connected to a CSST fitting.
  • The electrical service grounding system.  This connection may be made at either: the ground rod, the ground-wire running to the rod, or in the electric service-panel (also known as Circuit-Breaker Box or Panel).

*** Source:


To Further Reduce The Risk Of Lightning Strike Damage To CSST

Separation Between Locations Of CSST & Electrical Wiring.

This Is A Recommended Building Practice.

  • CSST Should Be Properly Bonded  & Grounded. The bonding conductor shall be no smaller than #6 AWG copper or equivalent.  References irc  2006 G 2411.1, IRC 2012 2411.1.1.
  • CSST can be bonded anywhere along the electrical service grounding system.  CSST can be connected to a metallic water piping coming into the home.  Most new homes today do not have metal water lines, they are PEX / plastic and CSST my be grounded to something metal.
  • Care Should Be Taken To Maintain As Much Separation As Possible From All Other Electrically Conductive Systems in a building.


  • electrical wiring
  • metal ductwork
  • metal water pipes *
  • metal chimney liners
  • All continuous Electrically Conductive Systems listed above should also be bonded.  * NOTE: Metal water pipes are grounded.  They are connected to metal pipe running through the earth (ground) into the home.

CSST Gas Lines Versus Flexible Appliance Connectors

There is a difference between CSST Gas Lines and the similar looking yellow Flexible Appliance Connectors (FAC).  While both CSST and FAC are made with stainless steel & carry gas — that’s where their similarities end.  CSST is a Gas-Distribution System.  FAC is a short length of tubing designed to connect the gas-distribution pipe to the gas-burning device.

Click Here To See The Difference Between CSST Gas Line and Flexible Appliance Connectors;  CSST & Flexible Appliance Connector Side By Side

How To Identify FAC:

  • FAC does not require bonding.  This is because they are connected to a bonded (if properly installed) gas-distribution system.
  • It is between 1–6 feet long
  • FAC are commonly found between the home’s gas-supply lines and the gas equipment.
  • FAC have a factory-installed connectors on each end.
  • FAC corrugation is highly visible.  As compared, CSST is sheathed and the corrugation is not highly visible.

A Change To The Property Inspector’s Form In Texas

Effective September 1st, the Texas Real Estate Commission (TREC) adopted a new Property Inspection Report Form   (REI 7–5).  

Language was added to the “Consumer Notice Concerning Hazards or Deficiencies” section of the form — to notify consumers of the potential hazards regarding lack of bonding on gas piping, including corrugated stainless steel tubing (CSST).  This notice is found in the Property Inspection Report on page 2 of the preamble and TREC Form No. OP-I.

TREC (Texas Real Estate Commission) exists to safeguard the public interest and protect consumers of real estate services.  In accord with state and federal laws, the agency oversees real estate brokerage, appraisal, inspection, home warranty, right-of-way services and timeshare interest providers.  Through education, licensing and regulation, the agency ensures the availability of qualified and ethical service providers, thereby facilitating economic growth and opportunity across Texas.

The complete news article about this change can be seen here: New Property Inspection Report For CSST


Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in Richardson, Plano and Garland.  We service all homes in southern Collin and Denton Counties with no travel charges.

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service.