Corrugated Stainless Steel Tubing (CSST) - Know What You're Dealing With

Corrugated stainless steel tubing (CSST) is not a new product and has been installed in natural gas systems for quite some time. Although I have always been familiar with it, I've never specified it on project that I have designed. It's primarily used in residential construction and doesn't suit the commercial projects that I work on. I was not aware of any issues with this tubing from the engineering side and was surprised when I became aware of the hazards associated with CSST from the firefighting side.

Brothers Gone Too Soon

Sadly, I became aware of the issues with CSST following two LODD's. Both tragedies took place in a neighboring state and one of the lives lost was known by firefighters that I know from training and/or social media. If you are not familiar with the circumstances around their final calls, I encourage you to honor their memory by reading the reports and educating yourself. Their stories prompted me to do some research as a designer and as a firefighter. I was quite surprised at what I learned.

For those that are not familiar with CSST, it is a flexible, thin wall tubing used to distribute natural gas or propane typically in residential occupancies. Most people associate CSST with yellow, corrugated tubing because that is probably what is most commonly found. The shape and color of the tubing can vary based on the age of the tubing and whether it is meant for distribution or as an appliance connector. It is preferred because it typically results in less joints that can leak and is easier to install than more traditional steel piping. However, it can be damaged easier and is more susceptible to failure from contact with electricity which is a serious liability to firefighters.

Newer versions have a black coating and are provided with arc shielding. The coating does has a flame and smoke spread rating. Although the newest versions are ANSI and Lighting Code rated, there are concerns that the testing is not sufficient because the tested ratings do not reach a high enough current level to match what is experienced in common lighting strikes. This is what has caused the most recent LODD's.

It does seem to be relatively safe if it’s installed properly, but that's the problem. It's only as good as it was installed and it can be installed by the weekend warrior. There is a difference between distribution tubing and appliance connectors which may not be understood. They are not the same and not meant for the same application. There may be improvements to be made in its construction and some companies are proactive. Gastite has been improving its product over the years to make it safer and even tries to work with the fire service to make a safer product. 

The bottom line is that fire departments need to be educated. CSST is not flawless, but it's critical that the correct material is used and installed correctly. Some of the newer products are better, but still need to be improved. Firefighters need to beware of legacy installations as they will be less safe than newer installations and materials. Home owners should be encouraged to update older systems that aren’t as safe as newer systems. Local authorities having jurisdiction should mandate that installers submit certifications with permits to show that they are qualified to the latest standards and are installing the latest material technologies. Making sure that installations and the materials used are the best possible to ensure firefighter safety is crucial.

Resources

•Lightning Fire Research Google Form

•CSST Info

Be Smart - Stay Safe!

The Importance of the 360 Size-Up

The importance of performing a 360 size up makes a huge difference in the operation of a structure. Keep in mind size up can be performed by simply walking around your first due area and checking out new construction. Let’s look at some simple factors I came across in a new residential community.

Picture #1

• Two story wood frame single family home

• Appears it could be balloon frame (although weird for new construction)

• Only one door is in plain sight

• Bottom window of the 1/2 corner is a bit raised appearing there may be a basement level or storage area below

Picture #2

• House is actually a three story residential

• Basement is designed to be fully furnished

• Basement level could possibly be used as an apartment (could cause a hazard if the stairway between the basement and first floor is illegally blocked for privacy)

• Two additional means of egress located off the first floor balcony on the #2 side and the basement level door

• From the rear it’s clear it’s not balloon frame

Again, just a few small factors to hit on. Do you notice anything else?

Outside the Box 360

Performing a 360 upon arrival of a residential structure fire is crucial. Everyone always hits on building construction, type of occupancy, number of floors, and visible fire or smoke.

Did you notice a vehicle in the driveway, indicating someone may be home?

Did you see that the vehicle has a handicap placard on the license plate, indicating the owner may have a disability of some sort?

You walk up to the front door and notice children’s toys in the yard. Do kids live here?

Remember to look at the roof, utility lines connecting the house, solar panels, and satellite dishes. All these things could cause a hazard for crews operating on the scene.

You may arrive on scene and find a lot of clutter in the yard, leading to you assuming there may be hoarding conditions in the residence. We often find ourselves in tunnel vision and not looking at smaller aspects of the scene.

We want to hear from our followers. What are you looking for when you arrive on the scene?

Until next time - work hard, stay safe & live inspired.

Cloud Ceilings

Cloud ceilings are not new and have been around for a while. They are, however, becoming more common and more complex. I’ve noticed a trend over the last few years where clouds have increasingly become a regular part of the interior design and the architectural ceilings in spaces where aesthetics are important or it's a "community" space where occupants will gather on a regular basis. These ceilings are also taking many different shapes and sizes and come in a variety of materials. I have, on multiple occasions, had to design sprinkler protection around floating panels of ceiling tiles, sheet rock, open grid ceilings, fabric panels, wood slats, and geodesic patterns. Designing around these ceilings has always been a challenge but the NFPA is providing guidance with the last few versions of Chapter 13.

Historically, the issue was whether or not you had to sprinkler above and below the cloud ceiling. The ceiling was considered an obstruction and guidance was found in the code sections dealing with obstructions that were either less than or greater than 18" from the face of the deflector. Some instances may have required applying the open grid ceiling section as well. In 2016, the NFPA began to address cloud ceilings in Chapter 13 and then again made further, more beneficial, updates in 2019. Cloud ceilings became defined and the rules for determining when the space above the cloud can be considered a concealed space were provided. These sections determine when sprinklers are only required at the cloud ceiling level, and not above the cloud. Basically, the code provides guidance to determine whether or not the cloud is a sufficient heat collector to initiate sprinkler head operation. This decision is based on the size of the cloud, the size of the gaps around adjacent clouds, and the height of the ceiling. There are additional factors such as sprinkler types and construction materials that play into the decision matrix. The NFPA has even provided some suggestions with respect to seismic concerns. Depending on how the cloud is supported and secured to the structure above, you may need to provide some flexibility in your piping system by utilizing elements such as flexible sprinkler drops in order to accommodate the shifting of the clouds in a seismic event.

A sprinkler designer has many challenges and factors to consider when designing around cloud ceilings. The bottom line is that the design must be code compliant to ensure optimum life safety for the building arguments. There are other factors that must be considered such as aesthetics, constructability, and cost. A designer can't just design a system with sprinklers above and below the cloud ceiling instead of doing the work to interpret the code. It's not the correct design and it drives up the cost for the owner. Working with the architect can also be a struggle. They spend time developing a unique design element of the building and the fire protection designer wants to put an ugly sprinkler head right in the middle of it! Both sides have to work together to find a resolution that not only works but is aesthetically pleasing as well. Although this isn't a fire protection designer's priority, it's providing a quality design that keeps clients coming back.

As firefighters, we need to pay attention when we find ceilings like these. We all know the importance of air movement in an active fire and recognizing the flow path is critical to firefighter tactics and safety. These ceilings may mask heat or smoke and delay the identification of the flow path resulting in us working below heated air or smoke (unburned fuel). It is important to know how the clouds are suspended. Are the clouds hung from rods/cables or are they secured to a rigid structure attached to the deck above? The clouds could move around when hit with a hose stream making your attack difficult or could possibly become a hazard if they fall. They could carry significant weight or become an obstacle when advancing the hose line. The clouds may even be an illusion. For example, in the picture on the right, is that a cloud ceiling or are the doors attached to a sheetrock ceiling that has been painted black?

The bottom line is that success starts early. We need to get into buildings and find out what's in them. When we find an atypical element like a cloud ceiling, we have to investigate to find out why it's there, and how it can impact our tactics and safety. Then we must share this info with our crews. Keep your eyes open, ask questions, and talk. Don’t wait until you're involved in a fire event to figure this out.

Be Smart - Stay Safe!

Building Firefighter Development (buildingfirefighters.com)

About the Author
E.J. Henninger has been designing building systems for more than 20 years. He is currently a Senior Engineering Operations Manager working with a team to deliver plumbing and fire protection designs for a wide range of projects. He has also been a volunteer firefighter for more than 10 years and is currently the captain at a rural Fire & Rescue Company with an active role in the training program. E.J. actively supports the fight against cancer through the International Association of Fire Chiefs and his annual Firefighter Relay Challenge. He is happily married to his beautiful wife of 25 years and has three wonderful sons.