Understanding UL Nomenclature for Firestop-Through Penetrations: Part 3

So, you are now armed with an amazing tool that will help you elicit the best out of your firestop installers. If you are worried you won’t remember all these letters and numbers, email me and I will send you a cheat sheet you can print out, keep in your wallet or pocket and refer to it before or during your inspections. At the end of UL Nomenclature: Test Yourself! I will tell you how to get your hands on a few secret tips to get more out of your installers. This is valuable for inspectors, firestop foremen (with trained crews or crews in training to be the best), and anyone with firestop subcontractors (mechanical, electrical, plumbing, fire sprinkler, drywaller, masons, general contractors, architects, building owners, developers, insurance review staff, hospital or other maintenance crews).

I really like food. So, the last step of your lesson on understanding the UL nomenclature is going to be a food analogy. This last step is understanding when you need the 8000 series detail. I like to think of this as a fantastic buffet. If you go to a buffet that has great shrimp but you are allergic to shrimp, that doesn’t mean you can eat at that buffet. It just means you won’t likely be eating the shrimp (unless you are chasing it with shots of Benadryl). However if you want to eat chocolate cake and they don’t have it, you are out of luck. If chocolate cake is what you really want then you have to go to a different buffet.

The same is true with the 8000 series details. If you have a detail that allows the use of cables, metal pipes and insulated pipe; but your field condition only has insulated pipes and cables, can you still use this 8000 series detail? The answer is, YES you may. Just like at the buffet you don’t need to eat the shrimp.

However, if your field condition has plastic pipes and cables then you cannot use this detail. The plastic pipe is like your chocolate cake. You are out of luck and have to look for a different detail.

On our next blog post we will put you to the test and see how much of this you can remember. We will give you some field applications and see if you can identify the correct UL nomenclature. This will help you drill through the firestop submittals so you can identify the correct UL detail to use in various applications. I hope you find this useful. If so, please let me know. If there are other topics you want me to cover then let me know that as well. If you want to review Rated Joints, Nomenclature ABC’s, and 123’s.

Want me to email you a cheat sheet you can keep in your wallet to peek at when you need it? You might need it for the next blog posting!

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Halpert Life Safety Consulting LLC’s

“Saving Lives for the Life of your Building” TM

Our mission is to make a colossal impact on the level of life safety of your building and on the talent of your people. We provide consultation, training, quality control and third party special inspection related to firestop and passive fire protection. We consult for the building industry in the New York/New Jersey (NY/NJ) metropolitan area, as well as across the United States and internationally.

Understanding UL Nomenclature for Firestop-Through Penetrations: Part 2

So, now that you understand the letters a little (see here for review), let’s get into the numbers. You are going to have to just memorize these. The 1000 series details are for metal pipes and conduits. So, with the list below and the information in the previous blog post you now understand how someone could easily tell you that a duct through a gypsum wall would be a WL 7000 series detail (mentioned from a previous blog post).

  • 1xxx- metal pipes
  • 2xxx- plastic pipes
  • 3xxx- cables
  • 4xxx- cable trays
  • 5xxx- insulated pipe
  • 6xxx- electrical busway
  • 7xxx- mechanical
  • 8xxx- combinations

Chew on that list for a while. Maybe pick two or three of the applications you deal with most of the time and focus on that your first week. Add a few other numbers to your repertoire the next week. You might start with 1000, 5000 and 7000, then add in 3000, 4000 and 8000, then tackle 2000 and 6000 in the end (just don’t forget them).


There is a little more information that might be helpful once you have digested the list above. 2000 series will be plastic pipes but it will also be where you will find the details for innerduct or plastic conduits. (Side note: if you have innerduct on your project please email me because there is a strong chance it is being done wrong. I plan to blog on this later, but you need my help now if you have innerduct being firestopped).

The 7000 series details are going to be where you will find details for ductwork but it is also where you will find the detail for miscellaneous metal applications such as threaded rod or uni-strut through a rated assembly. If you are inspecting a firestopped unistrut please check inside the center of the strut to be sure the installer has the proper firestop placement. This is difficult to see, which makes it easy to miss. Another fun one is the seismic bracing for sprinkler pipes. Did you know this needs to be firestopped if it penetrates a rated assembly? It not only needs to be firestopped around the pipe where it penetrates the wall but also INSIDE the pipe because it creates a chimney through which smoke and toxic gas can spread. UL listed details change on a regular basis, and they vary from one manufacturer to the next so it is likely that this will require an EJ (Engineering Judgment). Please review the International Firestop Council’s Guidelines for Evaluating EJ’s at this link. They are an excellent resource for other firestop related information as well.

We have one last thing to cover before we are done talking about the number sequence in the UL nomenclature. We have not yet discussed the 8000 series details. If you have an application that has a copper pipe and an insulated pipe, you can’t use the 1000 series detail because it doesn’t deal with the insulated pipe, which is considered combustible in a fire scenario. You can’t use the 5000 series details because of the bare pipe. You have a lot of information to take in. Now let’s go on to Part 3 and we will go over the 8000 series details!

If you have innerduct on your project, please email me because there is a high chance it is not being installed properly. If it is being done right would love to hear about it. I will give you a high-five, a pat on the back and maybe even buy you a beer if I run into you in the local pub.

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Halpert Life Safety Consulting LLC’s

“Saving Lives for the Life of your Building” TM

Our mission is to make a colossal impact on the level of life safety of your building and on the talent of your people. We provide consultation, training, quality control and third party special inspection related to firestop and passive fire protection. We consult for the building industry in the New York/New Jersey (NY/NJ) metropolitan area, as well as across the United States and internationally.

Understanding UL Nomenclature for Firestop-Through Penetrations: Part 1

(#3 in a Series)

The UL firestop nomenclature, as you saw in Understanding UL Nomenclature for Firestop-Rated Joints  is a series of letters and numbers. It is a sort of ABC’s and 123’s of firestop installation systems. The joints are very much straight forward. The through penetrations are slightly more involved because you are dealing with the various MEPS (Mechanical, Electrical, Plumbing, Fire-Sprinkler) trades and subsequently, a lot more variability than is found with joints. The good news is that the first letter and the first number are the most important things to focus on. This makes it a little easier to understand.

The first letter will be one of 3 letters W, F or C. W stands for wall (I told you it was easy) F stands for floor and C stands for combination. This means that the assembly can be either a floor or a wall. However, if you want to remember that it stands for concrete you will be very close because concrete is the only construction material typically used for both floors and walls and the UL listed details that start with C can be used both for floor applications as well as wall applications. The other letters give you more information about the assembly. For example WL is a framed gypsum wall WJ is a concrete or block wall, FC is for stick built construction and FA would be a concrete floor 8” thick or less.

A, B, C, J and L are the key ones you will deal with. If you want more specifics here is the actual break-down:

A = Concrete floors less than or equal to 5 inches thick
B = Concrete floors greater than 5 inches thick
C = Framed Floors
D = Steel Decks

E = Floor Ceiling assemblies consisting of concrete with membrane penetrations (update 3/2/2019)

F-I = Not Used
J = Concrete or Masonry Wall less than or equal to 8 inches thick
K = Concrete or Masonry Wall less greater than 8 inches thick
L = Framed Walls
M = Bulkheads Marine
N-Z = Not Used

The numbers get a little more in-depth and we will get into that in Part 2.

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Halpert Life Safety Consulting LLC’s

“Saving Lives for the Life of your Building” TM

Our mission is to make a colossal impact on the level of life safety of your building and on the talent of your people. We provide consultation, training, quality control and third party special inspection related to firestop and passive fire protection. We consult for the building industry in the New York/New Jersey (NY/NJ) metropolitan area, as well as across the United States and internationally.

Understanding UL Nomenclature for Firestop-Rated Joints

Welcome back! I’m excited that you believe knowing the UL nomenclature for firestop is important enough to learn about! If you are a firestop inspectors, general contractor or first tier subcontractors who have hired firestoppers, know that by the end of this series you will have a few tips on how to make your job easier and command better quality from your firestop installers. If you are a firestop installer this blog series will help you prepare for an educated inspector or general contractor and help raise you head and shoulders above your competition. These tips we will share are only effective once you know how to identify the details. Let’s get started making your life easier.

I will take it easy on you for the first bit and we will start with the rated joints.

UNDERSTANDING UL NOMENCLATURE FOR FIRESTOP- RATED JOINTS

When you are looking at the UL details for rated joints, there will be a combination of two letters, then a third letter followed by a series of four numbers. Once you are finished reading this blog you will understand the nomenclature or naming system for the UL listed firestop systems for rated firestop joints. You will know what all of the letters and numbers mean, and you will be able to thumb through a firestop submittal easily and find the detail you need for the application you are about to install or inspect (this last step may take a little practice, but if you care enough to read this far then you are smart enough to figure it out quickly.)

Understanding the UL nomenclature for rated joints is easy once someone explains it to you. When you see F think floor, when you see W think wall. This means that an FF system is a floor to floor-joint application, a WW system is for a wall to wall joint application and an FW is for a floor to wall application. HW is a head of wall application and if you need it BW is for a bottom of wall joint. There are also CW or CEJ for Curtain Wall joints but they are tested to a different standard so we won’t really go into it here. Link to category 7-firestopping for glazing industry

Then, there will be a third letter; either a D or an S. D is for a dynamic system; which means the system was tested to allow for movement. We will get into the details of how it is tested, why it is important and much more in a later blog. So lets keep going. If the third letter is an S, then it is a system tested for a static joint system; which means it was not tested for movement. Most all buildings will experience movement, whether it is from live load, dead load, wind load, thermal load, seismic load or who knows what else. Therefore, it is in the best interests of the team to be very careful about when and where they allow the use of static systems.

Next will be a series of numbers, but the first digit will be the most important. If the number series starts with a 1 then the joint will be 2” or less, if it starts with a 1 then it will be more than 2” but less than 6”, if it starts with a 2 then the joint will be more than 6” and less than 12” and so on.

When you understand the UL nomenclature you can easily rifle through the firestop submittal to find the right group of firestop details that should be used to install or inspect the firestop application. Someone well versed in the nomenclature can tell you that a duct through a rated gypsum wall should be installed according to a WL 7000 series detail. They can’t tell you what material, what size duct, if it is insulated or bare, what annular space is allowed or even if retaining angle will be required; without finding the actual detail. However, this basic information will get you to the right group of details much faster and from there you can go over the specifics to make sure the field condition appropriately complies with the UL listed assembly. In a later blog we will actually dissect a few details to help you better understand the layout.

Next we will go over the UL nomenclature for through penetrations.

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Halpert Life Safety Consulting LLC’s

“Saving Lives for the Life of your Building” TM

Our mission is to make a colossal impact on the level of life safety of your building and on the talent of your people. We provide consultation, training, quality control and third party special inspection related to firestop and passive fire protection. We consult for the building industry in the New York/New Jersey (NY/NJ) metropolitan area, as well as across the United States and internationally.

Learning the firestop UL nomenclature will save you time!

Are you an inspector or installer of firestop materials? Do you work with one? If so, I’ve got some information you NEED to know. First, if you are easily offended, then PLEASE stop reading, because I’m about to be brutally honest with you. If you do not understand the firestop industry’s UL nomenclature (the naming system for firestop details), then I would respectfully challenge whether or not you are doing your job to the best of your ability. The good news is, I’m on your side and I want to help. I am passionate about sharing this knowledge because I think it will only serve to improve the construction industry and make safer buildings. An added benefit is that it will help mitigate your construction liability. If you are ready to learn a little more, join me for the next few blog posts discussing how to understand the UL numbering system.

The UL nomenclature is the ABC’s and 123’s of firestop tested assemblies. There are other testing agencies, but UL (Underwriters Laboratories) is the predominantly accepted testing agency for through penetration firestop assemblies, as well as construction rated joints and perimeter containment. Since UL is the biggest name, understanding the naming system they use (the nomenclature) is important. Lucky for you, it is simple too.

But first; let’s discuss why it is important for you to understand the nomenclature. If you are installing the firestop material, you need to know which set of direction to use. This will ensure the installation is going to function as expected and actually stop fire and smoke from spreading prematurely through the building.

If you are inspecting firestop installations, you need to be able to find the correct UL listed assembly in order to conduct any inspection properly, otherwise you are just guessing if it is right. The problem with that, is that if it is done wrong and the inspector doesn’t notice, then the installer assumes they have done a good job and so does everyone else on the project team. This weakens the entire industry because it is accidently promoting poor workmanship and not through laziness, but through lack of knowledge. This blog post is an attempt to change your knowledge level and with your help, ultimately I want to change the industry.

If I have convinced you that you need to know more about the UL nomenclature, then read on. We will start to talk about what the letters and numbers mean and how you can use this knowledge to your advantage.

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Halpert Life Safety Consulting LLC’s

“Saving Lives for the Life of your Building” TM

Our mission is to make a colossal impact on the level of life safety of your building and on the talent of your people. We provide consultation, training, quality control and third party special inspection related to firestop and passive fire protection. We consult for the building industry in the New York/New Jersey (NY/NJ) metropolitan area, as well as across the United States and internationally.