How Fire Rated Assemblies Are Tested

It’s a New Year, so I thought I would play around with a new medium. I have pulled up a few old videos from various training segments I’ve recorded in the past 5 years. Here is a brief general discussion about how rated assemblies are tested. There is so much more I want you to know about this, but this is not a bad start and it segues into some of the older blog posts we have shared.

In order to make this information practical, so you can use it in the field, please remember that knowing how assemblies are tested helps you understand how they fail when not properly installed. Think about the hose stream test when you are looking at applications with large annular space, with insufficient annular space or installations with just a smear of sealant. These are both critical to the performance of a firestop installation.  The various hyperlinks will bring you to different segments for further discussion if you are interested in learning more.

Please share this with anyone you think might benefit from this information.

As always, if you have any questions or even topics for future blog posts, don’t hesitate to reach out to us.  We are happy to help when we can.

 

UPDATE: Jan 6

I want to give a HUGE shout out to RICK BARONE for making  a correction for me. This video clip was edited from one of the first classes I did when I started teaching again, and as with most things we are new at, there were errors.  I noticed it during editing a few months ago but forgot to comment on it when I posted it.  Rick says it better than I could so I will just include his comments here and say THANK YOU RICK.  I love when people support others to do better.

“You have some inaccuracies in the video…The time temperature curve is controlled by the test facility….If your test specimens furnace isn’t at 1000f at 5 minutes it will be because the lab tech didn’t maintain the time temp curve within the prescribe tolerance. The customer doesn’t fail, the lab must abort the test and rerun..usually at their own cost if they are a credible lab…but a nice start with a new communication vehicle..” Rick Barone 1/5/2017

Firestop Classes in New Jersey

Hi everyone,

I am excited to announce the schedule for Rutgers Fall classes.  There are  heaps of great classes available in this program, but the ones I am teaching are:

Understanding the Requirements of Firestop Special Inspection- 1705.17

Special inspection (SI) of firestop is a requirement in NJ and since there is no licensing process the local jurisdictions (AHJ) are responsible for ensuring that the contracted inspector is actually qualified.  This class goes over the reporting requirements and a few ways to identify if your SI is up for the job.  Participants will even walk away with a few inspection tricks up their sleeve to try out on their next project.  This class is designed to help the AHJ’s keep the hacks out of their jurisdiction. While there are three slides specific to the NJ building codes, most of the information relates to ASTM E2174, ASTM E2393 and ASTM E3038 and the Chapter of the IBC as it relates to special inspection of firestop.

My favorite comment about this class last semester: “That changes everything!”

Classes will be on Friday, Nov 6 in Parsippany NJ & Thursday, Nov 16 in Cape May NJ


Inspecting Grease Duct Wrap-

We have a bit of fun in this class and do a hands on installation of grease duct wrap on an actual duct.  Okay, so its not a “real” grease duct, because I have to schlep it into the class room and screw it together.  It would fail the light test with your back turned. But the installation is real, the installers and inspectors are real, and the other materials are exactly what is used in the field.  We do an inspection and learn how the mock field installation would fail the required lab tests.  This helps the participants be able to take the technical information into the field more effectively.  Then we talk about some more complication installations, what to look for during inspections.  We end with a discussion of the various materials that are found in the field and this semester we hope to have samples of the factory insulated materials so we can add this to the discussion.

My favorite comment about this class last semester: (at our first break about 90 minutes into a 5 hour class) “I only signed up for the class because I needed the credits for my license.  I didn’t think there was really anything for me to learn here.  My class yesterday was great.  I expected to learn a lot, and I did.  I gotta say though, I’ve learned more in this class already, than I did all day yesterday. “

Tuesday, Nov 28 in Evesham NJ & Tursday, Dec 14 in Sayreville NJ

 

If you are interested in joining any of these classes, or having us present the class in your area,  please email us.

What Exactly is a BEAD of FIRESTOP?

If you have been following this blog, then at this point you are well aware that the annular space is the gap between the penetrating item and the rated assembly. We have also mentioned several times that when there is NO gap it is considered point of contact. Did you know that the firestop needs to be installed differently when there is no annular space than when there is? It makes sense if you think about it. If there is annular space, many firestop details will require 5/8” of sealant be installed INTO the annular space. If there is NO space in which to install the firestop, many installers simply smear the firestop sealant over the top of the rated assembly. When they do this, it is not always obvious that there is point of contact. The installation can easily appear compliant if destructive testing is not conducted. The reality is, however; that the installation does not conform to a tested and listed assembly and in a fire scenario it there is a risk it may fail prematurely. Unfortunately, many installers are not even aware of the liability they create when they do this. It is a bit of a catch 22, if you will. If the inspectors do not catch this mistake, the installers assume that they are doing it right. The jurisdictional inspectors bear no liability for missing this during an inspection, however the new building code requirement calls for third party special inspectors in high-rise and risk category III and IV buildings. These inspectors would likely be liable for missing this during an inspection. The firestop installers certainly would be liable, because they are the ones who are supposed to assess the firestop assembly before the installation. They are the ones who are supposed to know the details they themselves submit.

So, if you are installing or inspecting these firestop installations, what should these point contact locations look like?

First of all let’s be VERY clear that point contact and continual point contact are two different things. An example of continual point contact is when a 1” pipe or conduit is put through a 1” opening. There are very few firestop details that allow for continual point contact. When a firestop detail says annular space can be 0”-1” that generally means that a 1” pipe can easily be installed in a 2” opening. If the pipe is concentrically installed (centered in the opening) then the 1” pipe in a 2” opening would give you apx ½” annular space all the way around the pipe. If it is off center then the annular space would be different on either side. If it is all the way to one side of the opening then the annular space is 0”-1”. The firestop detail will typically call for a bead of firestop at the point of contact. It will also define the size of that bead, so lets take a closer look at what is expected in this case.

Most of the penetrants will pass through the rated assembly at a 90-degree angle. If we remember our geometry classes from way back in middle school, the hypotenuse is the face of the triangle immediately opposite the 90-degree angle. In the diagram below, it is marked as C. When the firestop detail says that the bead of sealant needs to be ½” it means that the hypotenuse must measure ½”.

Now, at what point is the bead supposed to start or stop? This is not clearly detailed in any requirements but my personal opinion is that if the firestop installation calls for ½” of sealant to be installed INTO the annular space, the bead should be required in any space that the required ½” of sealant cannot be installed. This is not a standard. This is not a requirement. This is just Sharron’s opinion, so take it as that. Adopt it as your own if it makes sense. If you disagree, please let me know your argument against it.

On the other hand I have seen inspectors that require that if a bead is installed, it shall be installed all the way around the penetrant. I disagree with this because I feel it encourages installers to complete continual point contact installations and just throw the bead around the entire penetrant.

If there is no tested and listed application for continual point of contact, it should not be allowed. Here are a few examples of continual point contact details. These are the only times it is acceptable to have continual point contact. You will note they are all 1000 series details, meaning metal pipes. WL1054 is an example of a metal pip through a gypsum wall and CAJ1673is an example of a metal pipe in a concrete or block assembly. Please look at item 3, where you will see it allows for continual point contact and will require respectively a ½” or ¼” bead of sealant. Now you know what a bead of sealant should look like and how to measure it properly. Remember it must be tooled to ensure it sticks both to the substrate and to the penetrant. In the case of these two details, please also know that these two manufacturers likely have details that could utilize a more cost effecting non-intumescent material. It should be noted that BOTH of these details need to be done with intumescent firestop and not the less expensive products.

So with that, let me know what you think. Do you agree? Do you disagree? What do you see in the field?

Thank you for taking the time to learn a little bit about the industry in which I work. If you have questions about any of this don’t hesitate to reach out to me. In the meantime, keep learning and continue to make projects better.

 

 

Understanding the Hose Stream Test- part 2

Hose Stream

Last post you read an excellent article from Chad Stroike of HIlti and this week I want to add a bit to it.

 

Imagine a room on fire. As the temperature mounts, the pressure inside the room will increase. We want to know that the integrity of the firestop system will be able to withstand the impact of this pressure increase. As the temperature grows metal elements through the walls and floors will expand and contract, twist and contort. They will be hot on one end and not on the other. Thin wires holding lights can snap, leaving the fixture to swing and slam into a rated wall. Furniture or heavy duct assemblies can crash into rated walls.   We want to know that the firestop installed in these rated assemblies will have the integrity to withstand these potential hazards without becoming dislodged. This is one more reason for this hose stream test on top of everything Chad mentioned in his article. If you haven’t read it yet, you can get it here.

 

Something I found interesting when I first learned about the hose stream test, is that it is done half way through the test. This means that a wall or floor is taken off the furnace half way through the duration of the test and immediately subjected to the hose stream test. Picture a concrete floor with pipes or ducts that are red hot. Now picture a 30-PSI stream of water hitting the red-hot pipes and smoking hot concrete assembly. You can imagine the steam engulfing the room and shrouding your vision, the steam hissing in your ear and the smell of smoke choking you. Then, after this segment of the test is completed, you would walk to the “non-fire” side of the assembly and look for signs of water breaching the concrete floor. If there is light coming through the assembly or any sign of water that may have penetrated the floor, then the test assembly has failed. If the assembly passes, this is just one step in the process because the assembly must be burned for the entire duration. This means that many rated wall, rated floor or floor ceiling assemblies are likely tested twice; once for the full duration of the fire test and then often a second time for the hose stream test. This may not be the case for concrete or block assemblies because they don’t degrade as rapidly in a fire and may survive the hose stream test even after the full duration on the furnace. Certainly for gypsum assemblies, the fire side is basically sacrificial. It won’t last long in a fire test, so UL’s requirement is that the hose stream test is conducted at the half way mark of the test (but not more than 1 hour). This means that a 1-hour fire test will have a hose stream test conducted after 30 minutes. A 2-hour test will have a hose stream test conducted after 60 minutes, as would a 3 or 4 hour test.

 

If you ever get the opportunity to witness the hose stream test, you should. If you are at all a geek like me, you will appreciate the impact it makes on the test assembly.

 

Next week, we talk more about scenarios where the hose stream can cause a test sample to fail.   Now that you have a better understanding of how firestop is tested, you can better understand why certain elements of the tested and listed details are critical to the performance of the assembly and critical elements to be inspected.

Understanding the why behind whats important when inspecting firestop?- Part 1

When you look at a UL listed detail that has a 1-hour F rating, what does that tell you? At a very basic level you can expect the assembly was tested and didn’t let fire through for one hour. There is so much more to it than that and once you understand, it might change how you inspect firestop. Keep reading and let me know if it does.

 

F RATING- as defined on UL website

The F-rating criteria prohibits flame passage through the system and requires acceptable hose-stream test performance. Lets break this into two parts. First it is saying that fire doesn’t breach the assembly during the test period. Obviously, with firestop, we are trying to contain a fire; so we want to know that the rated assemblies will keep a fire at bay for the designated time period which is known as the F rating. A 1-hour rated wall is expected to contain a fire for 1 hour. F ratings for firestop are 1, 2, 3, and 4 hours. The temperature inside the furnace during the test will increase as the duration of the fire increases. For example in a 1 hour test the temperature will be at least 1700F (538C) at the 1-hour mark and 2000F at the 4-hour mark (1093C). Surviving these temperatures is still not enough to obtain an F rating for a rated assembly. There is one more critical element involved in the test procedure called the hose stream test.

 

HOSE STREAM TEST- what it is and isn’t

I have sat through too many classes on firestop, codes and what not, only to cringe when I hear the instructor tell the class that the hose stream test replicates impact of the fire fighting methods on the fire rated assembly. It is like nails on a chalkboard to me and I can feel it running down my spine. (Yes I am that much of a geek, that it bugs me to the core) By the time the fire fighters are on the scene with their hoses, any loss of life in that area has likely occurred. Property damage is done. Firestop serves no purpose at this point, because the integrity of the assembly has failed and fire has breached the wall or floor. Fire fighting methods are not part of the firestop test. I believe that understanding this critical element of the firestop testing process is integral to the proper inspection of firestop. We will get into this more shortly. In fact, a lot more, because this is a 5-part discussion about why the hose stream test needs to be better understood in order to improve firestop inspections. For now however, I would like to share this article by Chad Stroike of Hilti. Chad does an excellent job explaining the hose stream test, why it is part of the fire test standard and what it is intended to replicate.

Thanks to Chad and to the IFC for this great article.