Welcome back to the series where we talk about “stuff we see wrong in the field.” This blog is going to discuss a few challenges we have found with PEX lines in wood framed buildings. If you are working on a concrete project that is using PEX, you should still read this just in case you are making the same mistake. We hope it is useful.
Here is our field condition:
The plumber drilled a hole through the two by fours that are sitting on the plywood floor to frame the wall that will be built. The hole is less than ½” larger than the pex line they are running. This gives them just enough space for the bracket the plumber is using. In the field, they call them mickey mouse ears. I’m not sure what they call them in your area but here is an example of one.
The firestop installer simply smeared firestop around the pex line and covered the mickey mouse ears. It wasn’t until we did destructive testing that we discovered the problem. So, if you are an inspector on a project that is not going to require special inspection, please walk the site before the firestop is installed to see if they are using these things. If they are, you may want to ask a few questions. If you need some help give us a call.
The mickey mouse ears use up all the annular space that you need for the installation of the firestop material. With plastic pipes you typically need to have an intumescent firestop material. This is one that is capable of expanding to fill the void created when the plastic pipe melts away during a fire. The intumescent material can close down the opening and prevent the passage of fire.
Intumescent materials act like most things in nature. That is to say that they move in the area of least resistance. That means if it is sitting on the top of the two by four and adjacent to the pex pipe, when it starts to expand its going to move in the area of least resistance. This will be away from the pipe.
For this reason, the intumescent material needs to be forced into the opening so that the two by four, the concrete or the drywall can contain the sealant as it expands so it is forced into the center of the opening. This enables the material to close down the opening as the plastic pipe softens in a fire and yields to the expanding intumescent sealant.
This is also why, when a plastic pipe touches the side of the opening, its required to have a bead of sealant, which is a build-up of material along the edge of the penetrant and against the rated assembly.
However, when a detail allows for annular space to be 0-1” for example it does not mean that you can have 0 annular space all the way around the opening. If this is allowed the detail should say “continual point contact” and few details do.
There are a few ways to handle this. One would be to not use the Mickey Mouse ears. Another would be to install the firestop first and then force the sealant into the opening as you push the bracket into place. Inspection would be difficult and ensuring proper sealant depth during installation would be imperative.
If you run into this issue, let us know how you handle it.
Thanks for taking the time to read this. We hope you found it valuable. If you did, please leave comments and let us know what other topics you would like to see us address in future blogs. Share this with anyone who can benefit and keep learning. Check back for more in this blog series as we discuss other field issues we encounter.
Thanks for joining us yet again for a continued discussion about firestopping shaft wall assemblies. The discussion today will continue along the question asked during the start of this never-ending series of “how do you properly firestop penetrations in a shaft wall”. If you remember a few weeks ago I told you, that 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.
The last few posts were talking about the bare metal pipes- aka the 1000 series firestop details. Today we will talk about the 2000 series details, which as you know are the plastic pipes. Plastic pipes provide a whole array of challenges. This means they are easy to do wrong. They are combustible and depending on the chemical composition of the material they will melt between 200F and 500F. If you want to know more about how they are tested please check out the past post (be sure to read the amendment before watching the video). https://halpertlifesafety.com/how-rated-assemblies-are-tested/
First let’s tackle the gypsum wall applications. It will be critical that this be done in stages. For this discussion, we are going to look at a Hilti detail. The detail we are going to look at for this application is WL 2217.
Item 1: It allows for a shaft wall with 1-5/8” studs.
Item 2: It allows for maximum 4” PVC or CPVC. I spoke with a contractor one time who said, “It lists plastic pipe, so its fine.” NOOO. This is not true. When you are dealing with plastic pipes there is SO MUCH to look at.
- the size
- the material
- it must list the proper material if it only lists PVC then you can not use CPVC or any other type of plastic, pex, polypropylene, sprinkler pipes and the list goes on…and on….
- The right gauge or thickness- for example the plastic pipes used for IT are not the same as what is listed above, even if they are made of PVC hey are not likely the right schedule.
- If your field material is cellular core, you need to be sure the submitted detail allows that material to be used.
- If the submitted detail only lists closed or supply lines you can not use that detail for a vent or drain line.
- If your submitted detail is for a specific brand name of pipe, you can only use that detail with that brand of pipe. For example if the detail calls for a polypropylene pipe called Aquatherm, you may not use that detail with a different manufacturer.
- The annular space MUST be adhered to and in some cases, it can be very restrictive. The larger the pipe, the more critical the annular space will be, except for polypropylene pipes, which are really combustible and require unique applications even on smaller pipes. By unique I mean more restrictive annular space and aluminium foil tape around the pipe prior to the installation of the collar.
That is a lot to take in and we have not even gotten to the firestop installation yet. I am going to let you sit on this and throw any questions my way. We will tackle the firestop installation next week, because there is a lot to share with you on that as well.
So have a great week, be productive and keep an eye out in the field for all of your plastic pipe installations. Next week we will go over what to verify when you are looking at the firestop installations. For now, the next time you are looking at a firestop submittal that includes plastic pipes, you now know there is a LOT to deal with.
If you want an extra set of eyes to look over a firestop submittal on your project, please give us a call. We are offering free review and follow up phone call for your project. You just have to send us your firestop submittals and we can schedule a time for a phone conference.
It’s completely complimentary because we want to shed some light on how to do this right. There is of course one catch. This offer is only for contractors who have a desire to do things the right way. If you want to cut corners, you don’t want us on your team.
If you want to build a strong team, we promise after just one project with us, your team will be stronger on their next project. We have been bloging on firestop since 2015. Wee have been sharing information, in hopes of improving this industry. If you have a team of people who want to do this right, we guarantee that after one project with us they will be better able to:
- identify problems before they are built
- know how to resolve common problems
- they will have a list of things to look out for (yes a physical list to check off- but that is only for our clients)
- understand the codes related to firestop
- know the requirements of special inspection
- understand the handful of standards related to firestop
- understand how to troubleshoot common problems
- when to call for help, and who to call (it’s not always HLS)
If you need help, give us a call. If you want to be sure you are heading in the right direction we can help you with that also. We hope to hear from you if we can help. We are offering a complimentary review for the month of July.
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 a recent blog on Adhesives.org that poses a challenge to the industry to come up with a better solution for this edge of slab firestop. It’s a two part series and the first segment can be found here. If you have any ideas and want to get connected to a manufacturer, I’m happy to help make connections for you. If you have problems or questions on a project don’t hesitate to contact us for help.
Thanks for reading along so far. We have covered a lot in this series on shafts and hopefully you have been able to put some of this to use in the field. Next up, let’s look at what you should see when you are walking in the field looking at all that firestop stuff. Let’s put all this information to work for you.
First, you need to have the firestop submittals that show the firestop requirements for all of these shaft applications. If you don’t have the details, you can’t properly evaluate the installations.
Let’s walk a site together (You will need to use your imagination here). Say we are on the 5th floor of a hotel project. We are looking at a mechanical shaft. We have bare pipes and insulated pipes stubbing out of the wall to provide water to the bathroom. The shaft liner is up, but there is no firestop on the pipes. We go up to the 6th floor, the drywall is on the outer layer of all the shafts, but they have firestopped only about half of them. As you walk down the hall you see an area where they have not yet firestopped the penetrations into the shaft wall and you can see that they have not firestopped the shaft liner side. This is a problem. Firestop is required on both sides of a wall, even a shaft wall.
Let’s take the same scenario, but this time they did have firestop on the shaft liner side on the 6th floor. However, when you were on the 5th floor you noticed that the hole that was cut for the small insulated copper pipe is just big enough to get the pipe and the insulation through. The insulation was almost touching the cut edge of the drywall all the way around. You don’t have firestop submittals for the project so you can’t tell that the detail requires annular space of 0-1/2” and what you have in your field condition is continual point contact. The other thing you can’t see is that the firestop detail calls for 5/8” of firestop in the annular space. Since there is no annular space there is no way to achieve this depth requirement. You have some problems. The first problem is that you don’t have your firestop submittals so you can’t reference what is required when you talk to the installer. Second, they have created an installation that can not be finished correctly. Remember those blogs where we talked about continual point contact and the importance of proper annular space?
Please also remember, if you are looking at a block wall, they will have to firestop both sides of the wall, or one side but do it two times. This is true both for joints and for through penetrations. If it is a shaft, you likely can’t get to the inside to check on the installations so you may need to go to the bottom of the shaft before it is closed off to get a look, or you can conduct destructive testing to confirm that it was done right. Please also remember that the firestop details have to match the field installations. If they don’t, it is non conformant.
If you are working on a project and you have questions about your firestop submittals, or installations please do not hesitate to give us a call. We are happy to help when we can and if you are close enough we might even swing by to help out if our schedule is open.
The 2015 IBC code section …don’t worry, it will be painless and its SUPER useful information. Stick with me please!
Section 713 is on shaft enclosures and there are a few things you really need to know. I’m going to generalize and just tell you to go online for the specifics when you really need them (or hire me and I can give them to you).
Generally a shaft has 4 sides, a top and a bottom. Your shaft may have 3 sides or it may have 10 sides, but for simplicity we will assume it is like most shafts and has 4 sides. It MUST have a top and a bottom because remember your floors are required to have a 2 hour rating (in most concrete buildings) and the shaft has to match the floor’s rating so that you can have an unprotected hole in the floor that could potentially run the height of the building.
It has to have a bottom, which could be the ground floor, or it could be a horizontal rated assembly made of concrete, gypsum or in some cases firestop materials.
It also has to have a top. That can be the roof or again it could be one of the rated assemblies we talked about. If you have a penetration through the top or bottom of the shaft you will have to firestop those penetrations.
Guess what! If you use a horizontal gypsum assembly then there are no UL listed details for penetrations through a horizontal shaft wall assembly. You automatically have to get an EJ. Is that included in your firestop submittals? It should be!
Now the top or bottom of your shaft could be part of a room, for example if you have a trash chute or linen chute then the bottom of the shaft can be the laundry or trash room provided the surrounding walls are rated and you have no prohibited penetrations.
More on prohibited penetrations in our next post! If you have shafts on your project or are concerned that your firestop submittals might be missing something, as always contact us here.
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.
Firestop can serve a number of unique features that are not directly related to STOPPING FIRE. A properly firestopped residential property can reduce the noise from a loud neighbor. It can reduce the wandering smells from a bad cook. In hospitals it can reduce nosocomial infections. This is the idea that you go into a hospital with a broken arm and leave with a cast and the worst case of the flu you’ve ever had. It can also save your life, even when there isn’t a fire.
There was a case in Orlando FL where residents were very lucky. They were lucky that one family was smart enough to recognize something was wrong and go to the hospital. The neighbors were lucky that a nurse was alert enough to notify emergency responders to ensure other neighbors were not in danger.
So, what happened?
Construction workers left a generator running and the residents suffered carbon monoxide poisoning. According to NJSHAD around 500 people die every year in the US as a result of accidental carbon monoxide poisoning. There was another case where a man decided to commit suicide by leaving his car running in his garage. His garage was attached to his house and his house was attached to the neighbor’s house. His attempt to end his life also cost the life of his entire family and his neighbors young family.
The same way that a properly constructed and properly firestopped building can reduce the transfer of both sounds and odors, it can also reduce the transmission of deadly gases not only during a fire but also in a case such as these.
So, make sure your firestop is done right, install detectors and check the batteries regularly.
If you have any questions about your property and whether or not the firestop is being installed properly, don’t hesitate to contact us.