Firestop in Shafts is Often Done Wrong, so Someone Asked, “How do We do it Right?” (part 4)

How did you do with the questions?  Hopefully, they made you think a little about this firestop detail, the product, the various field conditions you might encounter and firestop details in general.  Let me start by saying the answer to every single question is NOPE!  Even question 2 and 7.


Let’s take another look at the questions as we provide the answers.


If you want to review the product cut sheet is here


The firestop detail is here


Question 1: My field condition has a sleeve in a block wall. I can still use this detail because the firestop device is a sleeve, right?

No. The tested and listed detail (WJ2274) did not allow for a sleeve or say that a sleeve was optional.  That means that if there is a sleeve in your field condition you have to get a different detail.  Maybe one exists, but if it is not in the submittal package it doesn’t count for this project.

Question 2: What kind of anchors do I need to use to secure this to the wall?

You don’t need any anchors, that is one of the selling features of this new product.


Question 3: My field condition is using Aquatherm SDR 11.  It’s the same brand, so I can still use this, right?

It may be the same brand, but this detail calls for blue and Aquatherm SDR 11 is green.  Blue is not green so you cannot use this detail with green pipe.


Question 4:  The sleeve I am using is 10” long and I don’t want to see it on the occupied side. Is it okay to push it in flush with the outside of the wall?

The last line in 3A before listing the product says that the device shall be centered within the wall and extend equally beyond each surface of the wall.


Question 5: We are using brand X firestop sealant and we don’t want to have another sealant on site to confuse people with, so its okay if we use brand X firestop with this new sleeve thing, right?

Sure, go ahead and use brand X .BUT know that you are installing a detail that is non-conformant and you are accepting all liability if this installation should fail. In other words, NO you can’t, unless you can get documentation to support this and that is not likely.


Question 6: The aquatherm pipe is insulated but I got sleeves that are big enough to go around the outside of the insulation so this is fine, right?

There are details for insulated PP pipes, but this is not one of them.  The interesting thing is, that if you need an insulated pipe you look in the 5000 series details. When you do this, some of the insulated plastic pipes can be found here. Alternately some of the can be found in the 2000 series detail. It is an odd thing, but at the moment this is the way the details are laid out.


Question 7: I am using 3” Aquatherm green. My hole is 5” and my pipe is centered in the wall with the same annular space all the way around.  Can I still use this detail and this product?

See this chart for product information


The chart shows you that the 3” pipe has an OD of 90 mm (which is 3.543 inches- thank you Google unit converter)  That means that the annular space of our perfectly centered pipe will be .73” all the way around.  The detail manufacturers installation instruction require a minimum ¼” annular space (see installation date item 7). We have that covered no problem. The detail allows for a maximum annular space of 7/8” which is .875. With a 5” opening, 3.54 OD of the pipe, leaves 1.46 around the pipe but its centered so we takehalf of that which is .73.  We are allowed 7/8” annular space and .875 is less than .73 so….HA..this one is right..  Sharron was wrong…we can use this detail…except that, as we went though all of this math we forgot one little thing.


Take a second look at 2A. 

2 A. Polypropylene (PP-R) Pipe – Nom 6 in dia…. It does not say maximum 6 in dia. If it did say max then you would be fine and you could use this detail.  However this detail is only for use with a 6” pipe and only the type and brand of pipe listed.


If you are thinking this is a trick question its not.  It is something that is easily overlooked and I wanted to point out how quickly a contractor may be able to convince you that this system is okay.  I also wanted to remind you that you have to take a closer look.

Remember we are talking about shaft walls. These are integral to the life safety of the building. HLS is here to help those who want to get it right.  To quote the wonderful Dr. Maya Angelou “Do the best you can, until you know better. Then when you know better, do better. “  You may have missed this, or other things we have blogged about on past projects.  There is nothing I can do to help you with that, but I certainly can help make sure you get it right from here on out.


If you want us to walk a site with you (in the NY/NJ area) so you can see what you might do better, give us a call.

Firestop in Shafts is Often Done Wrong, so Someone Asked, “How do We do it Right?” (part 3)


If you were with us for the last two blog posts you saw that there is a lot to look at when dealing with plastic pipes, and even more to deal with when those plastic pipes are going through a gypsum shaft assembly. Today we are going to tackle the concrete or block wall applications.  The shaft walls were not so bad, as long as it was staged/planned/schedule appropriately. Concrete or block walls however don’t have this same luxury and often have to be firestopped from one side.


When we were talking about the WJ1000 series details for our metal pipes I was able to share with you some relatively newer tests that were tested for a one sided installation.  Before those were available the typical option was to use an engineering judgment that often required mineral wool recessed well into the wall, maybe ½” depth of the firestop sealant, followed by more mineral wool and another layer of ½” depth of firestop sealant.  This was providing the same basic installation materials in a slightly different order and from one side of the wall.


Plastic pipes are tougher because they are combustible. If you remember the time temperature curve, then you remember that the temperature inside the test furnace must be 1000F at the 5 minute mark. Plastic pipes melt between 200F and 500F, which means in no time flat the plastic pipes will be gone. Insert time temp curve


This means that firestopping from one side is going to be more of a challenge and the larger the pipe, the greater the challenge. One great way to tackle this challenge is with another one of my favorite problem solving products that you can see here.


This is a metal sleeve with sheets of intumescent material. It comes flat, so if you are installing it say on a 4” pipe, its best to grab a 2” pipe. Wrap the sheet metal and the wrap strip around the smaller pipe, then uncoil it and it snaps easily around the 4” pipe and you can slide it into the opening.  I do not normally suggest the use of an EJ but as we walk through the detail you will see why it is needed. (but with any luck Metacaulk will test this as a one-sided application so you don’t even need an EJ)


For this review let’s look at WJ2274.  This particular detail is for Aquatherm Blue Pipe.  We mentioned a little bit about this polypropylene pipe and others in previous blog posts. We just want to remind you that this is a unique product and since this detail is for Aquatherm blue, SDR 17.6 then it is limited to this material and this material only.


I am going to throw out a handful of questions for you and Wednesday I will share the answers with you.  The questions don’t all relate to the same field application.


Question 1: My field condition has a sleeve in a block wall. I can still use WJ2274 because the firestop device is a sleeve, right?


Question 2: What kind of anchors do I need to use to secure this to the wall?


Question 3: My field condition is using Aquatherm SDR 11.  It’s the same brand, so I can still use this, right?


Question 4:  The sleeve I am using is 10” long and I don’t want to see it on the occupied side. Is it okay to push it in flush with the outside of the wall?


Question 5: We are using brand X firestop sealant and we don’t want to have another sealant on site to confuse people with, so its okay if we use brand X firestop with this new sleeve thing, right?


Question 6: The aquatherm pipe is insulated but I got sleeves that are big enough to go around the outside of the insulation so this is fine, right?


Question 7: I am using 3” Aquatherm green. My hole is 5” and I have ¼” annular space on one side around 3 o’clock. Can I still use this detail and this product?

See this chart for product information

Firestop in Shafts is Often Done Wrong, so Someone Asked, “How do We do it Right?” (part 2)

Okay, so I am hoping that in this last week you have walked around your projects that have plastic pipe and identified the sizes of plastic pipes you have on your jobsites. What type of plastic they are, if they are solid or cellular core, if they are open or vented and that you have firestop submittals for each and every one of your field applications whether they are going through a shaft or not.  I know our discussion is about shafts but the information I am sharing is not restricted to shaft wall assemblies.


Now we are going to look at what the firestop detail tells us we need to verify when we do the field inspection.  Here is the link to the detail, so you can follow along with

WL 2217

At this point you will have already verified that field installation conforms with everything we discussed in the last blog post and everything we discussed above.

The first step of the installation comes with the plastic pipe coming through the shaft liner.  Pay particular attention to this because its going to be tricky.


3B says that the collar needs to be friction fit. This means that if the outside diameter (OD) of the collar is 5” then the hole needs to be 5” and the collar needs to slide into the opening touching the cut edge of the drywall. If this is not cut tight, if the person with the drywall saw made jagged cuts, then it doesn’t conform with this detail.


But wait that is not the only issue here.  This detail requires the collar be secured to the shaft liner with toggle bolts.  If that is the case then those are the only types of anchors that can be used.  This means that drywall screws are NOT acceptable.  I could side bar for a while on why and I will get to that another time, but for now just know it needs to be mechanically fastened and drywall screws are not considered mechanical fastening.


Did you notice that there is another requirement?  The anchors need to include a ¾” washer.  Other details may call for 1” or even 1-1/4” washers.  If these are not used then there is a risk that the anchors can pull out of the wall as the intumescent material expands.  There will be a great deal of potential for movement and pressure applied on this collar so it needs to be secured strongly to the wall and all of these are requirements, not suggestions.



No joke: I was doing a training session with a field installer team and I went into a local Home Depot and asked where they had their fender washers. They guy looked me straight in the eye and said, “Ma’am we don’t sell car parts here at Home Depot. “  I walked away in shock and asked the next person, “Where are your nuts and bolts?”


Okay, so back to our firestop detail:

You may have noticed that there is no requirement for sealant on the shaft liner.  That is because the collar is friction fit into the opening and this will limit any air movement that would be stopped by sealant.


The outer layer of drywall will allow for a gap, but how much of a gap?  The detail says that the maximum size of the opening in the outer layers shall be 5”. That annular space shall be filled with FS One which is an intumescent firestop sealant. Then the collar shall be installed on the outside of the outer layer of the shaft wall assembly with the same anchor tabs, toggle bolts and washers.  One thing we didn’t mention is that the collar comes with anchor hooks and you will need to use 2 hooks for pipes 1-1/2” to 2” and three anchor hooks for pipes three and four inches in diameter.


As you can see, there is a LOT to look at!  There are a lot of steps to this as well. Now imagine how to do this same type of installation on a block or concrete wall. Clearly you cant, so how will you address that type of shaft wall assembly?  Check in next week and we will go over this and introduce you to a great problems solving product.  If your contractors forgot to install the collar on the shaft liner side, you may be able to use this solution as long as the hole in the shaft liner is not a mess.


Remember, if you want us to take a look at your project to be sure you are on the right track, we are offering a complimentary review through the month of July.  Contact us for more information.

Firestop in Shafts is Often Done Wrong, so Someone Asked, “How do We do it Right?” (part 1)

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).


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
    1. 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….
    2. 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.
    3. If your field material is cellular core, you need to be sure the submitted detail allows that material to be used.
    4. If the submitted detail only lists closed or supply lines you can not use that detail for a vent or drain line.
    5. 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.


Insulate your AEC firm from Terrorism Liability

We are so excited to be able to bring this new opportunity to the construction industry. This is a revolutionary way to protect your firm and your clients from. It is a new way to differentiate your company from your competitors with a new SAFETY Act protection.

There are an array of SAFETY Act protections. Typically they protect the developer of the anti-terrorism device, as well as the owner of the building who deploys it.

That changed last fall with the development of a new Qualified Anti Terrorism Technology that is the first to have implications for the architectural firms, their consultants, the general contractor and their subcontractors as well as the building owner.  This is a pretty exciting change for the AEC industry. It is a way for an architect or general contractor to differentiate itself from others. Read more about it here.  If you would like to take advantage of this new opportunity, contact us. We will be limited to the number of projects we can take on in the first few years.

Fire Moves Faster in Modern Construction- Wanna See?

You may have heard that modern house furnishings allow a fire to grow faster than in days gone by, but have you ever seen the difference? This video shows you just how much faster. It’s a shocking reminder that if there is a fire in a building you need to get out IMMEDIATELY. There is no time. Close your doors and get out.  Test your smoke alarms so they will work if you ever need them.

Watch the video here

This really hammers home the importance of both active and passive fire protection methods such as sprinklers and firestop.  If you need help getting your firestop right, give us a call. We can offer a great deal of support and we have been told that we save more money than our contract value. Making us more of an investment than an expense. Whether you are a developer, architect, GC, CM or even a sub who does their own firestop installation, Give us a call and see how we can help! 201-250-4193


Have a fantastic week everyone!

Isoclima HVAC Line Sets- If it’s used on your project you must read this!

Okay, I am going to vent for a moment.  I think this is the first time I have done this on my blog and this has been going since 2015. I am really frustrated with a certain company’s inability to respond to multiple requests to share information on thier product.  At this point, I can only assume that they are not sending me the requested information because it would incriminate them.  I could be wrong, but I am very suspicious at this point.

Have you ever seen this material on your jobsite?  I’m talking about the white foam that is going through the wall in the picture here.

This is an HVAC line set called Isoclima or Isopolar. You can check it out here.  During a recent site walk, we ran into this.  I had never seen it before, so obviously I had heaps of questions.   I figured it would be simple, contact the manufacturer and get the information we need.

What information do we need?

Well, we know there is a small copper tube inside the insulation, but since it is not clear what type of foam material the insulation is made of; it is not possible to identify what UL Listed detail we can use. The scary part is that whatever insulation this is, may have never been tested in the first place.  Even worse, there are some types of insulation that can not be firestopped at all because they won’t survive the fire test. (ASTM E814).


So, I thought it would be easy, simply email the company and ask what material is used for the insulation?….Has it been tested for flame spread and smoke development? Has it been tested to ASTM E814?  Three simple questions that let me know how to move forward.


The problem, is that the manufacturer has not responded. I have emailed them once a week for the last four weeks and I receive an automated email response thanking me for my query. I have four of them sitting in my in-box but not a single response to the questions I posed.


That can only lead me to believe that they have not tested it to ASTM E814, which means there are no firestop details. That’s not a HUGE deal, we just need to get the proper paperwork from the firestop manufacturer, except they are going to want to know what the insulation material is and we can’t share that information with them because the company who knows has been utterly non-responsive.


If you find this material submitted for use on your jobsite I would not allow the use until you can confirm it is possible to firestop it when it passes through rated assembly.   Bear in mind I am not saying that you CAN’T use this.  I’m just saying, without the proper documentation, you are creating a tremendous position liability.  As you make this choice you should also be aware that some of these foam insulations are incredibly flammable. Which makes me want to snag a scrap and see what happens when you try to light it.   If I manage to get sample and do my test, I will keep you posted.  If you decide to do this, be sure to have a fire extinguisher and/or a bucket of water and remove anything combustible from the test area.  Be safe, but let me know what the results are.


In the meantime if you encounter anything new on your jobsite and you want to know more about how to firestop it properly…please send me photos and information so we can share it with others who are interested.


All the best and thanks for checking in with us!

Firestopping Penetrations Through Shafts- Are you getting it right? Part 4


Welcome to a new week. Last week I threw a lot at you for a seemingly simple topic.   I hope that now, you understand a little more about how easy it is to get these installations wrong and what to look for on your next field walk.


Today I want to tell you why shafts are so important. I work mostly in concrete and steel structures. The bigger the project the happier I am.   The total dollar value of projects I have been on in the last 12 years has just broken $18 billion. Yes, that’s a B. This is a testament to how much I love BIG projects.


It doesn’t matter if you have a shaft that cuts through 2 floors or 30 floors, shafts are critical to the life safety of the building.


The floor is going to have a 2-hour rating. This means that if there is a fire, we expect the fire to stay on the floor of origin for at least 2 hours giving the occupants time to escape and in the US, giving the first responders time to do their job a little more safely. The penetrations through this two-hour floor must all be closed up and more often then not this should done with some firestop assembly. One exception to this rule is when we take the rating of the floor and run it up a shaft wall and connect it to the floor above. This means that if a fire starts inside the shaft, that fire, smoke, toxic gas and heat can access all the floors the shaft cuts through. In my mind the firestop in shafts is a critical factor to the level of life safety in a building. If these firestop applications are not done correctly the occupants of every floor the shaft passes through are at risk.


If firestop contractors are allowed to install firestop using methods that have not been tested, they are putting the building occupants and our first responders at risk.


Firestopping the 1000 series details are the simplest applications out there. In the last two blogs we have shown you that the proper installation for these simple applications entails a number of critical steps.


Now you understand why the IBC Chapter 17 on special inspections is in the codes. If you have a project with a special inspector, I challenge you to show them any WL1000 series detail with a 3-1/2 shaft wall and ask them if they can use THAT detail for a shaft application and see what they say. If you have a firestop specialty contractor, ask them the same question. If you have a plumber, mechanical contractor or electrician doing their own firestop scope of work please know that (with absolutely no disrespect to those trades) they are trained to work in their trade. Their trade does not include firestop. If you have a project that requires special inspection you probably want to be sure to hire a GOOD specialty contractor for a handful of reasons:

  1. You have one point of contact for all things firestop
  2. You probably have one firestop manufacturer on the job
  3. You are more likely to have someone who has some level of training and experience- both of which are going to be invaluable


If you want to take your project to a whole different level, consider hiring us to consult on your project. We will review your firestop submittals to be sure everything you need is documented – or at least if it is not, we can give you a list of what is missing. We will hold a preconstruction meeting that will help hold all the players accountable. We will share a list of best practices and we will help resolve conflicts before they happen (as much as we can, there is always that hairy monster that sneaks up on you at some point.) We are a single point of contact for all of your firestop problems.


If you have a project in the NY/NJ area and you wonder what it might be like to have us on your project, give me a call and I’d be happy to show you. From now until the end of June I will offer a complimentary site walk so you can get an idea of what your project’s weak points are (if there area any) and whether or not having us on your team will be a help. On projects with great contractors who want to do things right but maybe don’t have the knowledge, we can make a dramatic change for less than $20,000 and support you through the entire project. If you get resistance from your contractors but still want them to do it right it might cost you a bit more, but we can still give you the support you need to get it done right.


If you are not in the NY/NJ area and you think you are missing out, call me anyhow. We can offer you a complimentary review of your firestop submittals. It is amazing what those little pieces of paper help me tell you about your project.

Firestopping Penetrations Through Shafts- Are you getting it right? Part 3

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.


  1. The sleeve is a requirement and not optional:
    1. If you don’t use a sleeve then the mineral wool and sealant will not stay in place during installation.
    2. 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.
  2. You need to ensure the gauge of the sleeve is accurate.
  3. The overlap on the sleeve needs to be 2” minimum in order for it to:
    1. Comply with the detail
    2. 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
  4. 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.



  1. 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.
  2. 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.
  3. 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.

Firestopping Penetrations in Rated Shaft Walls- Are You Getting it Right? Part 2

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.