Do You Have Some Potentially Dangerous Gas Lines in Your Home?

If your home was built or remodeled after 1990, then it is possible that there is a potentially-dangerous gas line in your home. Corrugated Stainless Steel Tubing (CSST) is a gas line that has been installed in millions of newly-built homes in the US since the early 1990’s. It has also been installed during remodels in many older homes. CSST has been blamed for several house fires each year throughout the country since the 1990’s. These fires have particularly been in areas that are prone to severe lightning storms.

CSST was invented in Japan in the 1980’s as an alternative to solid gas lines in Japan which has a high degree of seismic activity. CSST’s flexibility allows gas appliances to flex and move during earthquakes without the gas line leaking or rupturing. In the 1990’s, plumbers began using Corrugated Stainless Steel Tubing in the US, and it became more popular due to its ease of installation, which lead to it being installed in more and more homes.

Before too long, several house fires were blamed on the CSST installed in the home. According to investigators, lightning strikes create very small holes in the CSST piping. These holes resulted in gas leaks which in turn caused the fires. Lightning strikes can create high voltages in metallic materials such as CSST even if the lightning does not strike the house.

Mike Morgan, owner of 
Morgan Inspection Services in Abilene, Texas, explained that because CSST is so thin it is much more susceptible to damage than other materials. Also, because the CSST is carrying flammable gas, it can create a very dangerous situation. As the high voltage in the CSST discharges by arcing across to some other nearby piece of metal, the spark produced is very hot and basically melts a hole through the thin tubing. 

Over the years, several things were attempted to protect homes from the risks of CSST. One solution was a complete ban of CSST by some municipalities and states. (Most, if not all, of these bans have been lifted.) Finally, in 2006, a solution was developed that entailed electrically bonding the CSST. The purpose of this solution was to prevent the high voltages from building up in the gas line. Studies have shown that bonding the CSST has lowered the number of house fires caused by lightning, but it has not totally eliminated these fires.

How dangerous is CSST? 

The number of house fires caused by CSST is relatively small, despite the fact that it has been installed in millions of homes. Also, according to the National Fire Protection Association (NFPA), there are between 300,000 and 400,000 house fires in the US each year. Current statistics show that only about 1% of these fires are caused by lightning. Since less than half of lightning-caused fires are blamed on CSST, the facts seem to show that CSST-caused fires are low compared to the total number of house fires. Some studies show that while CSST does present a risk to your home, it is not a big risk. There are many things that put your home at a greater risk of fire than CSST does. 

Studies show that the main causes of house fires in the United States are cooking equipment, heating equipment, smoking in bedrooms, electrical problems, and candles. This does not mean that you shouldn’t worry about CSST. Luckily, improving the safety of CSST in your home is a fairly simple thing to do. Its normally a fairly quick and simple thing for a licensed electrician to bond the CSST gas line in your home.

How do you know if you have CSST in your home? 

Mike Morgan, who has been inspecting homes since 2002, stated that “CSST is a corrugated tubing that is almost an inch in diameter. It almost always has a yellow plastic coating on it.” He said that one of the best places to look for CSST is in your attic, basement, or in the crawlspace underneath your home. He also said that you shouldn’t confuse CSST with the smaller, shorter yellow gas lines that run from the gas valve to your furnace, water heater, and stove. He continued, “these gas lines are not CSST, and they are considered safe.” 

Photo of typical CSST in an attic.

If you are unsure if you have CSST in your home, a licensed plumber should be able to do a quick inspection and let you know if its present. If you do have CSST, don’t panic. All you need to do is to call an electrician and have them determine if it has already been bonded or not. If it hasn’t been bonded, them have them bond it.