Firestop in Shafts: Common Mistakes & How to Fix Them (Part 1)

May 7, 2021 | Halpert Life Safety Consulting |

Thanks for joining us again for a continued discussion about Firestop in Shafts: Common Mistakes & How to Fix Them. 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
    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 correct gauge or thickness for plastic pipes used in IT differs from the specifications listed above. Even if they are made of PVC, these pipes may not meet the required schedule.
    3. If your field material is cellular core, ensure that the submitted detail accommodates its use.
    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.

          Have a great week, stay productive, and watch for all your plastic pipe installations in the field! Next week we will go over what to verify when you are looking at the Firestop in Shafts installations. Next time you review a firestop submittal with plastic pipes, remember there’s a lot to consider.

          If you need an extra set of eyes on your firestop submittal, please call us.  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.

          To strengthen your team, just one project with us will make your next project even more successful. We have been blogging on firestop since 2015 and that included Firestop in Shafts. We 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 construction begins.
          • know how to resolve common problems 
          • They will have a physical checklist of things to look out for, 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. We can help ensure you’re heading in the right direction. If you need assistance, we hope to hear from you! For the month of July, we’re offering a complimentary review.