Welcome back everyone. On Monday I left you with a bit of a challenge. I asked you if you could use WL1222 for a firestop application for a metal pipe going through a gypsum shaft wall. Then, I told you that the answer to that first question was NOPE, but I asked you to look closer at the detail to find the reason, and then I LEFT YOU.
The suspense is over, keep reading and you will find not only why you can’t use that detail, but we will share a detail that is applicable and a few cautions about the proper use of this detail.
Were you able to identify WHY you can’t use the WL1222 for a shaft wall application? If not, look at the detail once more, but this time focus on item 1A. Please click on the link above and open the detail so you can look at it.
Did you find the answer this time?
How many shaft wall assemblies have a stud that is 3-1/2” wide?
If you are thinking that the gap doesn’t matter, you need to tune in to a future blog post about T ratings. That discussion will take me into several different directions; so, I will side bar that discussion for a later date, but hopefully some time this year.
For now let’s just say that if your field conditions don’t match your paperwork then you are non-conformant. If you are non-conformant then you are creating a position of liability for your company and whatever company you are working for regardless of whether you are an installer, inspector, GC or owners representative.
For now, let’s get back to identifying the right solution. In this case, our contractor is using STI firestop. We know this because item 3 of WL1222 lists LCI and also because the firestop detail has the STI logo on it. Again, I don’t have a favorite firestop manufacturer. I have favorite sales people and favorite products but not a single favorite manufacturer. My stance is, if they have the tested and listed details to support whatever project I am working on, then they are good for my project! Even if I am stuck with a sales guy I don’t like, I still have resources within the various companies to get what I need. That said, it has been a while since I have run into a sales person who has not been capable, qualified, professional and helpful. They are out there, but I have been lucky enough to not run into them.
Since our installer is using STI, let’s try to stick with this manufacturer as we look for a detail. In this case when we go to their website, or contact the sale rep, the search for me ended with WL1251. Please click on the link and have a look at this detail. Take a moment to think about the things you want to be sure the installer does right.
Item 1 in this detail allows for C-H or C-T studs that are min 2-1/2” wide and 1-1/2” deep (item 1A). Item 1C offers a caution that the circular cut out cannot be larger than 10”.
Item 2 notes a sleeve. It does not say OPTIONAL so this means the sleeve is a requirement. If you don’t have one of these fun toys I suggest you get one because it will help you verify that the sheet metal is the proper gauge. This detail says you must have a min 30 gauge galvanized sheet metal sleeve.
Item 3 is the penetration and the annular space. Obviously a larger pipe or different type of pipe than what is listed will not be acceptable for use with this detail.
Item 4 is where you will find the information about how to install the firestop material and what is required
If you have a 6” pipe centered in an opening that is 3” larger than the pipe, you will be okay. However if you have an 8” pipe in the same scenario you would not be able to use this detail because in 1C it says the opening can’t be larger than 10”. This means that despite the fact that the detail allows for a max 2” annular space you cant have more than 1” all the way around if you have an 8” pipe.
- The sleeve is a requirement and not optional:
- If you don’t use a sleeve then the mineral wool and sealant will not stay in place during installation.
- If you tell me that the wall cavity is already filled with mineral wool so you don’t need the sleeve, then you are not thinking about what will happen in a fire scenario after the shaft liner has burned away and the mineral wool falls out along with the burnt gypsum board. The sleeve is a requirement for a reason, don’t let the installer skip this part.
- You need to ensure the gauge of the sleeve is accurate.
- The overlap on the sleeve needs to be 2” minimum in order for it to:
- Comply with the detail
- Be expected to maintain its integrity in a fire scenario when we remember the fire side of the wall is going to be gone as the fire rages
- The sleeve has to be long enough to be captured both by the shaft liner as well as the outer layers of the shaft wall. If it is too short you may have a problem in an actual fire scenario.
The only caution I have to share with you here is to be sure that the annular space is sufficient to allow for the installation of the mineral wool and the required sealant.
- If you are on a stick built project and the roofers are using 2pound density mineral wool on the roof, DO NOT ALLOW THIS TO BE USED FOR FIRESTOP. Installers may tell you, “it’s the same stuff….it’s rotten cotton” What they are missing is that the detail calls for a minimum 4pcf and I have yet to find a firestop detail that allows the use of 2pcf. It is probably fine for roofers, but it is not okay for firestoppers.
- If you have the chance to watch the installation, you need to be sure the mineral wool is recessed 1” into the wall so there is enough space to install the 1” of firestop sealant.
- If annular space is tight, installing 1” of sealant will be tough, if not impossible
That was with a gypsum wall. Below is a detail for a concrete or block wall. Take a look at the detail. What are the critical items you will verify if you are doing an inspection?
Is your head spinning yet? I will go easy on you with the next post. I promise! But if you are wondering how to firestop shaft applications, this is valuable information and we have only addressed the 1000 series details. These are the EASIEST details to deal with in our mechanical shaft application.
Thanks for reading this all the way to the end. I know there was a lot here. See you next time for more firestop information.
Welcome back to our discussion about firestopping shaft penetrations. With this post we are looking into the question of how do you properly firestop penetrations in a shaft wall assembly. First we will look at block wall assemblies. For the sake of this discussion we will assume these are shafts where we have no reasonable access to the inside of the shaft. Clearly, this will exclude stair shafts because in this condition typically we have access to the inside of the stairwell as well as the outside where the rooms would be located. For the sake of this discussion let’s say we are talking about a mechanical shaft so the penetrations might be 1) bare metal pipe 2) plastic pipe 5) insulated 7) ductwork. If you think my numbers are not in the right order please look at this post so you understand why the numbers are in perfect order. Looking at these different penetrations will help you maneuver through firestop submittals much faster, so please become familiar with the UL nomenclature.
If you have any questions or comments about the importance of knowing the nomenclature or asking for submittals feel free to contact me.
So let’s start with the easy stuff first. We know that wall applications have to be protected on both sides for the simple fact that we do not know which side of the wall the fire could start on. This makes it complicated because we don’t have access to both side of the wall in this case. If you have been following this blog post or if you have just now reviewed the link above, then you know the UL listed details we need to look at in the submittal will be either CAJ1000 or WJ1000 details.
My guess is, that what you need will be found in the WJ details because the CAJ details (as you know) can be used both for floor applications and for wall applications.
I’m a dinosaur in this industry (almost 20 years yup I’m a dinosaur- and yes I started when I was 12…LOL) and since I no longer work for a firestop manufacturer I don’t get updated on the new wiz bang details. I had to do a little digging to find you some examples of relatively new details that are perfect for this type of application.
You may have heard me say “I don’t have a favorite firestop manufacturer” so don’t think that because I should you use brand A that means they are the best. The best solution for any application is one with a third-party testing agency standing behind the applications as opposed to 1) the guy in the field “wingin’ it” 2) an engineering judgment.
That said, here is a perfect detail for your metal pipe through a concrete or block shaft wall: 3M’s WJ1108. This is not the only detail, other manufactures have a similar test, but since this tested system exists; I would suggest that jurisdictions not allow the use of an EJ for the simple fact that tested and listed details should trump EJ’s any day of the week for the simple fact that it that has not been tested.
Can you use this for a wall where you have access to both sides? Certainly, but whether you have access or you don’t, be very careful that this is installed properly. Both of these details require 1” of sealant. If you don’t have sufficient annular space then this installation will be difficult to properly install. If you are responsible for special inspection (or even the standard AHJ inspection) you may want to ask to be on site for several installations so you can be sure they install the mineral wool in a way that it is recessed 1” from the outside edge of the concrete. Clearly, if they don’t do this then they cannot install the required 1” depth of sealant.
Imagine you have ¼” annular space. Now, picture trying to install 1” of sealant in that space. It will be easy to make it look good when the installation is complete but it will be a challenge to do this right. As an inspector or part of the QC team, it’s your job to be sure its right. If you have any questions, contact us.
So, let ‘s move on to the gypsum shaft walls. In this case you know that we are looking at a WL1000 series detail. So first take a look at this detail, WL 1222
If we are going to install the firestop in stages as the drywall is installed, this means we will firestop the shaft liner before the outer layer of drywall goes up. So, does WL1222 work for this? Please take a moment to look at the detail and think about this question.
Have you looked at the detail and considered the question? If you think you can use this WL1222 for a shaft wall, I will tell you that you can’t. Go back to the detail and see if you can find out why? Tune in Wednesday to this blog post and I will share the answer with you.
Here is the second part of the post earlier this week. Hope this gets your creative minds whirling and if you come up with anything good I am happy to connect you with a firestop manufacturer or even a test lab to make something amazing happen. Check out the challenge here.
If you want to learn more about protecting commercial kitchen exhaust or the new requirements for AHJ’s with the need for firestop special inspection or when they are required we have some classes for you to consider. If you want information on other classes provided by DCA please see this brochure. Sharron is excited to be teaching these two classes again this year. I know we will be talking about codes and standards but we actually manage to have a bit of fun.
In our last blog post we talked a little about shaft walls, what they are made of and some things to keep an eye out for. We will build on that as we go.
Today we are going to look at firestop submittals as they relate to shaft wall assemblies, so the next time you are reviewing project documents you will have a better idea if something is missing. The easiest way to understand this discussion is to quickly review the UL nomenclature post found here so this will be easier to follow. If you do not know this nomenclature its much more difficult to conduct this exercise.
First let’s think about the RATED JOINTS. Let’s assume that the project has both block shafts and gypsum shafts. As you look at the firestop submittals pull out the HW (head of wall) details and look for the types of shaft walls you have on your project. For this discussion we will assume you have both gypsum and block shaft walls.
You will likely have a handful of HW details but if you have gypsum shafts you need to be sure the project has a detail for firestopping this gypsum shaft. When you look at the WL details for gypsum walls, you will notice it is not like the standard gypsum wall details, namely because the shaft walls are built differently so they need to be firestopped differently as well. This will require sealant at the shaft liner as well as on the outer layers of drywall. If you allow this wall type to be firestopped when the wall construction is complete, you will not have a compliant system because you will only have protection from one side of the wall. This would create a major liability for the installer as well as the GC, building owner and building occupants. If you are looking at a WL2000 series detail for plastic pipes, be sure to take a closer look, but do the same for all your penetration types.
If you have access to both sides of the wall, as you would in an elevator shaft, then it is easy to firestop the head of wall joint on a block wall from either side of the wall. Likewise you can firestop your through penetrations with either a CAJ or WJ detail. If you only have access to one side of the wall, you will need what is commonly referred to as a sandwiched detail and my guess is that it will likely be a WJ detail or possibly an engineering judgement. This would allow for firestop to be installed in four steps. Typically there would be installation of mineral wool recessed maybe 4-1/2” into the joint, then firestop sealant (let’s say it calls for ½” of sealant) then another layer of 3-1/2” of mineral wool followed by another ½” of sealant. There are 4 steps to this installation, which means 4 steps to any firestop inspection as well, unless the inspector wants to try to cut into this kind of joint application, which is going to be a challenge in and of itself. This also means that the firestop detail needs to show installation from one side if this is what the installers are doing.
That is what you expect to see when you are in the field, but when looking at the firestop submittals you need to be sure that the block wall detail that is provided can actually be installed on the project. Is it physically possible? You need to be sure there is a head of wall, bottom of wall and possibly a wall to wall detail for the gypsum assembly. It is not uncommon for a contractor to miss these details, so be on the lookout for them.
Next, think about what penetrations will be going through your shaft walls. The block and concrete walls often will not have access from the inside of the shaft so a sandwiched application needs to be used in many cases, though there are devices that can be used and installed from one side. If we are working on a project with you then we can help you determine which different manufacturers products would be best for various scenarios. Let’s say your stairwell walls are block or concrete. This means the firestop details you will need will start with either a CAJ or a WJ (potentially WK for thicker walls). You will need a 1000 series detail for your sprinkler pipes and conduits, unless you have plastic sprinkler pipes then you will need a 2000 series detail as well as a 3000 series for your MC cables. You won’t need a 7000 series detail for your ducts because they are going through a 2 hour wall and will require dampers. Pull out these details and be sure that if you only have one side access that the details will allow one sided access for the installation requirements. If not, you will need an Engineering Judgment. If you are in NJ, remember DCA does not allow EJ’s- sorry NJ.
Typically firestop installers will submit details for the various penetrations through a standard wall. These may be okay if the shaft wall type is included in what is allowed in the listed detail. If it is included, then you are fine, and if not then they need to submit a new detail. This will be found in item 1 of all details. These details will start with WL for gypsum framed walls and if it is a mechanical shaft you will likely have WL 1000 for metal pipes, WL 5000 for insulated pipes, maybe WL 2000 for plastic pipes. When doing the installation or inspection of these walls you will want to be sure to check annular space and sealant depth to be sure it conforms with the details. You will also want to be sure the installer firestops the shaft liner side before the outer two layers of drywall go up as you will see in one of the later posts.
We have given you a few things to be cautious about, but in our next post we will dig deeper into this and the building code. If you have questions about a recent firestop submittal please contact us for help.
Would you like to know how to make use of a firestop submittal in a way that will help you hold your installers accountable in a whole new way? If you are even thinking “maybe”, then you should join us for the 25th Fire Facts! It is put on by City Fire as an educational forum and is well attended every year.
We have a new session coming up Feb 2nd in Princeton. If you join us, you will leave with a new set of skills that you can put to use the very next day (or at least the following Monday). This is hands down my favorite class to teach. Don’t get me wrong, I have fun with all of my classes, but this one is packed with valuable information…and it’s free! Come for the CEU’s, come for the information and you will get some good food, great company and valuable information about firestop, hot works and carbon monoxide.
If you want to join us, please contact Melissa Palmisano for more details and to register. She can be reached at firstname.lastname@example.org.
HOPE TO SEE YOU IN PRINCETON!