If properly installed, your chance of a fire from CSST is as rare as a lightning strike
Many homeowners scratch their heads when they see bending yellow gas lines in their homes instead of the traditional black steel pipes. If your house was built in the United States between the early ’90s and mid-2000s, you likely have natural gas piping made from corrugated stainless steel tubing—a popular, flexible replacement for black steel pipes. While the upgrade is less likely to leak gas, corrugated stainless-steel tubing can lead to major house fires—if struck by lightning.
If you’re wondering what the hype is with flexible gas lines, let’s clear some things up. Flexible gas lines are made from corrugated stainless-steel tubing (CSST). These extremely flexible pipes are made from stainless steel and often come coated in a trademark yellow casing, though they can sometimes be black. This clever revamp of the traditional black steel pipes allows natural gas to travel to your fireplace, furnace, stovetop, and any other appliances that use natural gas.
In short, flexible gas lines are perfectly safe as long as they’re properly installed. A CSST that is not correctly grounded or bonded can leak natural gas or become ignited, leading to a major fire hazard.
Let’s look at exactly why that happens: CSST is extremely thin compared to the traditional 4 mm black pipe. At about 0.2 mm, or the thickness of two sheets of paper, the odds of lightning surging through improperly grounded and bonded CSST rise. If this happens, the electricity from the lightning can arc, puncture a hole in the line, ignite the gas inside, and cause a fire.
When it comes to house fires, you shouldn’t worry—obsessively at least—about your CSST. According to the U.S. Fire Administration, cooking is by far the number one cause of house fires nationwide, making up 50.2% of residential fires. Lightning strikes are much rarer, accounting for only a portion of the 1.8% of residential fires caused by natural disasters. Those odds are even lower if you look at how many lightning strikes lead to fires via CSST.
That said, when CSST pipes burst, the pipe turns into a potential giant lightning rod. If the CSST isn’t properly bonded electrically, this can lead to a disaster.
It’s important that you have your home inspected by a local pro, especially if you aren’t sure about the status of your gas lines.
Speaking of the status of your gas lines, knowing which kind you have is key to determining whether or not your home is at risk of a gas line fire or leak.
To see if you have CSST, look for long stretches of yellow-jacketed, flexible tubing in your basement, crawlspace, or attic. The short flexible connector to your gas-fired stove, furnace, or hot water heater is not CSST.
Flexible gas lines bring many benefits compared to their traditional counterparts. Consider the following advantages to determine whether they’re right for your home.
Improved safety: Flexible gas lines are generally more resistant to damage and leaks than traditional gas lines, making them a safer alternative in many ways.
Durable: These gas lines are also quite durable and able to withstand many environmental conditions and temperatures.
Installation ease: Since flexible gas lines have fewer fittings and connections, they’re usually easier and less expensive to install than other types.
Versatility: The flexibility of these gas lines allows them to work for many different applications, ranging from connecting fixtures and appliances to reaching through tight and challenging spaces.
Expansion ease: Most flexible gas lines use a multiport manifold system that allows for easy expansion should you add new appliances or rooms to your home.
Reduced leak risk: Flexible gas lines usually have fewer joints and connections than other types, thanks to their flexibility, which reduces the risk of gas leaks.
Lower maintenance: Flexible gas lines don’t require chemical injections to prevent corrosion, unlike many of their traditional counterparts, making them a lower maintenance option.
The cost to replace flexible gas lines usually falls between $2 and $4 per linear foot. Correcting an existing installation can cost as little as $100 while replacing CSST with black pipe can cost several thousands of dollars. In general, expect to pay around $250 to correct the existing CSST and about $4,000 to replace it.
To get a quote, contact a local home inspector or licensed electrician near you to inspect your gas lines. Tell them you think you have CSST and that you want to make sure it's been properly grounded.
Keep in mind running, installing, or repairing a gas line often involves two different fields of expertise. You may very well need to hire a local gas plumber to install the actual gas line and hire an electrician to handle the electrical circuit if any repairs are necessary.
