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.
There are a number of discussions related to the exterior facades and fire protection. The building codes have, for some time, required that the gap, between the concrete floor and the exterior facade of a building, be filled with something that can prevent the movement of smoke and fire to the upper floors. There is even a test standard developed specific to the unique dynamics of this particular application.
This is the first of a two part challenge to the industry to make something better then what currently exists. If you have any questions about an installation on a project you are on, contact me and I will help you figure out if there are any concerns.
We have the schedule for the next semester of classes at Rutgers.
The first class – Understanding the Requirements of Firestop Special Inspection will be in Vineland on Thursday, March 29th and at Budd Lake Holiday Inn on Tuesday May 8th. This class doesn’t go over what you need to do the actual firestop special inspection. We discuss how the adoption of the 2015 building code changes the responsibility of the jurisdictional inspector who is now responsible for identifying who is qualified to conduct this scope of work.
The second class is on the Installation and Inspection of Grease Duct Wrap. The first date this class will be available will be in Mahwah on Friday April 6th and the second class will be in Monroe on Thursday April 26th. In this class we talk about the test standard for grease duct wrap. We do some quick training on how to install the material, then we let half of the class participants install an actual mock up duct, while the other half of the class conducts the inspection. We discuss the various things to review during an inspection, and common errors. The class wraps up with a discussion about some of the more complicated grease duct wrap installations.
If you are interested in joining the class, please check this site for more details and registration.
If you have been following this blog you know how I love to do a series of posts on a topic. If you have been to one of my classes, you know how often I segue to other topics. This one is going to be a combination of these habits and we will come full circle, eventually (there is A LOT to share with you all).
This is going to be a series dedicated just to shaft walls. Our hope is that after this series you will have a few new tricks up your sleeve when it comes to reviewing firestop submittals in the early stages of a project and knowing better what to look for when you are walking a project during construction. This series is for firestop installers, inspectors, superintendents of any trade, building owners, architects or GC…anyone who ever has to look at that red stuff and wonder if it’s right or not.
Let’s start with looking at the different types of shafts and what purpose they serve from a code perspective.
WHY DO WE HAVE SHAFTS?
The building code basically says you have to firestop any hole in the floor, or you have to stick the hole in a shaft. There are some holes in the floor that you really need, such as the hole that is created for an elevator or stairs. There are other holes that you could firestop, but it’s easier to just protect the hole with a shaft, one such example could be a mechanical shaft.
Generally, when you build a shaft, it will have the same rating as the floors that it runs through, so in most concrete projects we are talking about a 2-hour shaft.
The 2015 IBC section 713 is all about shaft enclosures if you want some light reading. You can find copies on line these days.
WHAT ARE SHAFTS MADE OF?
Here are three basic types of shaft wall assemblies you will see: concrete, block and gypsum. We will discuss all three here and remind you of some common problems with each type. Bear in mind one shaft could potentially be made of all three materials.
Concrete shaft walls are the easiest ones to get right. One reason is because there are fewer rated joints that need to be firestopped. Also, it’s not easy to punch a hole in a solid concrete wall, so penetrations are typically planned for or avoided. Still, you may have penetrations for electrical, sprinkler or ductwork. Please remember that firestop on walls needs to be on BOTH sides of the wall. Let’s think about this for a moment and talk about the problem this creates for installers. If you only have access to one side of the wall, how do you propose protecting both sides of the wall? Hang on, we will get to that in a bit.
Block walls are not so bad to firestop either. That is except when you are talking about a stairwell, because then, the head of wall joint that requires firestop is often blocked by the stair runners. When the joint is not firestopped properly, this can leave the area vulnerable for the passage of fire, smoke and toxic gas. Keep in mind that the stairs are typically your means of egress in an emergency because you won’t be able to use the elevators. This means that getting the fire protection right in these areas is critical to the life safety of a building.
Gypsum shaft walls create the most problems we’ve seen, from a shaft perspective at least. It starts with the basic construction. Does the contractor know that they need to stagger the corners of the wall and not run both layers in the same plane? A typical 2 hour gypsum shaft wall is going to be made with 1” shaft liner and 2 layers of type X drywall. The seams of these two layers of type X should not line up anywhere, including at the corners. Since drywall shrinks during a fire, any seams that line up create an extra risk. The required overlaps allow for the shrinkage without the risk. Corners are critical because too often the drywaller lines up the two layers rather than staggering them making a straight line seam rather than a stair stepped seam.
Remember, regardless of what type of shaft you build, the head of wall joint needs to be firestopped. Remember also that it needs to be firestopped on BOTH sides of the wall. If you have an elevator shaft, then someone will likely have to ride on the top of the car to firestop the joints and penetrations inside the shaft. The same is true for a mechanical shaft except access will be… shall we say… limited, if not impossible.
Next up, let’s look at the penetrations through these shaft walls. They, too, need to be firestopped from both sides. If access is impossible there are a handful of alternate solutions. Many of these will require an Engineering Judgment that should be created following the IFC guidelines found here.
In our next post we will go over what to look for when you are reviewing the firestop submittals specific to shaft walls.
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
Hello again, welcome to part 3 of the series where we explain the difference between fireproof, firestop and fire block. You can get the new post here. If you missed the previous blogs here are part 1 and part 2!
Enjoy and keep learning and share this with the next person who gets here terms confused!
I am excited and proud to announce that I will be teaching at Rutgers in 2017. There will be two classes- one on Grease Duct Wrap Installation and Inspection and the other on Understanding the Requirements of Third Party Special Inspection of Firestop. They did not accept my 2 day class on Firestop Inspection and the Common Mistakes because there are other people who already train on firestop. If you are interested in joining one of the classes, please let me know and I will send you the schedule when it is pulled together. Have a great weekend everyone and when you get back to work Monday, be prepared to make a difference!