Membrane Penetration Firestop Part One

Firestop applications that only breach one side of a rated assembly are called membrane penetrations. They are often poorly reviewed. This is true of wall penetrations but even more true of floor penetrations.   If you have been following this blog for a while, you know we are big on offering information in multi-part series and this topic will be NO DIFFERENT. We will start with two different documents one from UL and the other from the IFC and we will build on those documents in hopes of helping you see what to look for on job sites. This doesn’t matter if you are an AHJ part of a QA/QC team or a special inspector. You need to know the information in this series to help increase the level of life safety and reduce liability. So please read and challenge yourself to apply this information on your projects.

We will start you on this UL document.

Here are a few key takeaways-

Plastic Electrical outlets-

  • Look for the UL logo
    • be sure it is listed for use in a rated floor/wall/ceiling that it is installed in
    • if you don’t find it, the box is not tested to be used in a fire rated assembly. You can’t just throw a putty pad on the non-rated boxes to fix the problem. It’s not that simple.
  • Check the size of the boxes, because even if it is UL listed it can only be up to a certain size before it requires a putty pad, regardless of its proximity to any other boxes. Metal boxes cant exceed 16 sq in, plastic boxes may vary by manufacturer depending on what was tested (and what passes) so look at the paperwork
  • When you are reading the firestop detail (because that’s everyones favorite thing to do RIGHT?!) pay attention to whether or not the application requires
    • a metal cover plate
    • a ball of putty  inside the box (I have never seen anyone do this unless they get called out- and I rarely see people called out even when it is a requirement)

Metal Outlet Boxes-

  • don’t assume that you can throw a putty pad on any sized box. Refer to the CLIV (the tested detail) for the limitations
  • depth of box is a big deal. We will get into this in a future discussion, but if you recall our conversation about shaft wall assemblies it is related too that. If you didn’t see that you can review here. 
  • Again if you install a box in a wall/floor/ceiling you have to be sure it is rated for that use. If it is rated for use in a wall, it can automatically be used in a ceiling or floor.

I know the firestop details for putty pads are cumbersome and painfully boring so if you have any questions, ask your electrician or your firestop installer for the CLIV document, email it to me and then let’s have a chat. I can help get you on the right track to ensure these are done right.


How One Jurisdiction deals with Patching Rated Walls (part 3)

You have all heard the whole, “What Happens in Vegas, Stays in Vegas” line from way back when?  Even before that, you have likely heard of the fire at the MGM Grand in 1980 where 85 people died and over 600 were injured. Well, the changes made to the building department in the years since, are lessons that shouldn’t be part of what stays in Vegas. They should spread to other jurisdictions and today I will discuss just one of these points, since it is in line with the discussion about patching rated walls.

Clark County Building Department covers the Las Vegas Strip and they take life safety seriously. I know you all do, but they take it to a different level and one that some of you may want to consider taking a closer look at. They actually have a FIELD INSPECTION GUIDELINE that tells, not only field inspectors, but also builders and facilities maintenance teams how they should be repairing walls if they want to pass inspections.

Have a look at it and let me know what you think. Are you doing something similar to this?  If you aren’t do you think it might be time to revisit how patches are made and if so, what do you think should change?  If you have any questions, don’t hesitate to reach out to us. If we can help we are happy to.


More on patching rated walls (part 2)

Thanks for the great response on the last post related to patching rated walls. There is a lot more I want to share with you in the future but I have to find time to create the content. I heard back from so many of you that you liked the post I thought I would at least share some more information  that is already created so you can take it a step further.

Three key reasons the California patch will fail in a fire test scenario:

  1. It will fail at the hose stream test. For more information on this, check out this series we did a while back on Hose Stream and imagine that patch, or any patch you accept being able to pass the hose stream test as it is described in these posts from 2016.
  2. It will fail when you try to achieve the T rating- which is required of all rated walls and floors. There is a bit of information in this article here.
  3. As the drywall patch (or GOD FORBID drywall tape and mud excuse for a patch) heats up in a fire it will shrink. As the existing wall dries up it shrinks as well. When this happens the gap between the existing wall and the patch material grows. This makes it easier for the patch to dislodge during the hose stream test and this gap will allow hot gasses through and that is how the T rating segment of the test will fail.

So, the next time you see a patch in a rated wall, please take a second look to ensure it is not creating a liability for your project and the community of people who will live work and play in the building when you are gone.

As always, thanks for taking the time to learn more about the industry I love. If we can help you on any project you are working on, don’t hesitate to reach out to us.


Are you patching rated walls properly?

I have seen some creative ways of patching walls. Some are UGLY and some are invisible. Here is a great video of how to make an invisible patch BUT you can’t do this on a fire rated wall. This California patch or butterfly patch will not survive the rigors of the ASTM E119 fire test.

If you have been in one of our training classes where we discuss how rated assemblies are tested then you know the two biggest ways bad patch assemblies may fail are either because the fail at the hose stream test segment or even before that as the wall tries to maintain a T rating and the growing gap between the original wall and the patch material shrinks as the fire consumes its mass and the growing gap allows for hot gas to pass through and it will fail at this point.

So, how do you properly patch a rated wall? Check out this guide from US Gypsum association to see if you are doing it right. USGyp repair of wall

If you are looking at a repair of a one hour wall that is relatively easy. Properly patching a two hour wall is a whole different story all together. If you have any questions don’t hesitate to reach out to us. We are happy to help if we are able.


Tall Timber Construction- tests codes and future projects

If you are looking for more information on tall timber construction check out this slide deck (yes another offering from UL/FDNY/IAFF forum back in January) This presentation shows more information about how the tests were conducted, discusses a handful of projects and then building code information. This presentation was delivered by Cleveland’s former Battalion Chief, Sean DeCrane and you are missing a lot just getting a peek, but even this peek offers a lot of valuable information if you are interested in learning more check it out.


Thank you to UL for allowing me to share this information.


Questions about tall timber construction?

Questions about CLT?

Here is another presentation from the UL/FDNY/IAFF forum  Meeting the Challenges of the Future Built Environment at the New York City Fire Training Academy Randall’s Island, New York City. This presentation was delivered by Raymond O’Brocki and discussed things such as the ICC Ad Hoc Committee on Tall Wood Buildings, their objectives, the tests and their findings. There is some great information in this slide deck and it was even more valuable when it was presented in person.

Thank you to UL for allowing me to share this information.


What the fire services need to know about CLT

Tall Timber buildings are now a code requirement. How is this going to impact your jurisdiction?  There will be a number of variables and one certainly should be the opinion of the men and women who will be responsible for fighting fires in such structures. In honor of these individuals here is a FIREHOUSE article on the topic so you can see what fire fighters think about tall timber construction.


A discussion of Cross Laminate Timber construction at UL Future Built Forum- Jan 2019

Thank you to UL, FDNY & IAFF for hosting the future build forum last winter. Today I would like to share with you a slide deck from a presentation by Susan Jones of AtelierJones Architects. While this is nothing more than the slide deck that she used for the presentation, it is nothing compared to what you would have heard if you were in the audience with me. She is passionate about the use to CLT (Cross Laminate Timber) as a way to build high rise structures and preserve the forests.

In this presentation you will see the home that she built with this material. She shared her passion and her story on this chilly January day earlier in the year and I hope you find value in getting a glimpse of what she share with us that day. You can view the presentation here. You will see photos CLT projects as well as of the fire tests where you will see “cribs” of wood to simulate additional fuel sources and explanations of the codes we will see in the 2021 IBC.

If you have any questions about CLT, I would love to be a resource for you but I am still learning about it myself and I am still on the fence in several ways. I hope to be able to share a stronger stance one way or another with you as things unfold more.

For now however, if you have questions about firestop on a project you are involved with do not hesitate to reach out to me. I am happy to support you if I am able.




UL Future Built Forum Intro

January 2019 in the middle of a “Polar Vortex” I attended an event that was worth braving the cold for.

I wish I could take you back to the event so you could sit in the room and hear the presentations. The speakers were fantastic and the presentations were PACKED with information. I want to thank Underwriters Laboratories, Fire Department City of New York  and International Association of Fire Fighters for sponsoring such a great event and I hope to be able to attend the next one. I learned not only from the presentations but from conversations with others in attendance who were all eager to learn and share. Can you tell I was in fire geek heaven for two days?

I can’t wait to share all of this with you. UL has generously allowed me to share the slides. Here is what they covered int he two days

There were several discussions about Tall Timber construction. they were presented by architects and fire officials. You likely know that the 2021 code will allow Tall Timber, or cross laminate timber up to 18 stories. Many people think, “WOOD BURNS that is a horrible idea!”  Well, wood does burn, that is a fact. Lets look at a few there facts.

  • ICC has reviewed extensive fire test data provided by the industry and approved it.
  • These buildings are going up all over the world. A quick google search will give you an idea of where and how tall.
  • Steel is strong, but according to this article in Fire Engineers it will lose its structural stability at 1100F. The time temperature curve used by US fire tests will require the temperature to be 1000F at the five minute mark and 1300F at the ten minute mark. Without properly applied protection, steel is very weak in a fire.
  • Wood burns, yes. As it burns that char that is created insulates the inner layer of wood and the structural stability of wood is lost in stages rather than all together upon hitting a critical temperature.

Before you dismiss this  idea of tall timber buildings as crazy,  I encourage you to learn more about it. If you are curious about my personal opinion (or even if you aren’t, you are about to get it) I like what I have seen in the fire data that has been presented. It is impressive, but not yet extensive. I am still on the fence, but I am eager to be involved with a CLT project so I can learn more. One thing I have learned is that QA/QC will be CRITICAL. Not that it is unimportant in concrete buildings or wood framed buildings, but it could prove a greater liability to those contractors who are not completely educated or worse willing to cut corners. If you work on a CLT project you can NOT have someone with the “we have always done it this way” mentality, because this is all new.  If you are working on a CLT project and want help with the QA/QC please call me.

The second discussion was on battery storage inside buildings. I did not attend this segment because of other obligations. I was able to return in time for the discussions on exterior facades and high rise fire fighting challenges.

I will share all the slides and I may share some of my thoughts along the way.

I want to again thank all of those involved in this event, the sponsors, the speakers, the organizers and the attendees. I was honored to be among you all and grateful for all you shared with everyone.  I hope to be able to attend any future events you have.




New Building Codes

Get ready NJ! The 2018 IBC will be adopted Sept 3rd.  That is just next week!  You can find a link to the IBC here  the copy with the changes for NJ are not yet available. If you are not in NJ you can always check out the ICC code adoption map at this link.

When an area adopts the 2021 we will see Cross Laminate Timber allowed up to 18 stories. It will be interesting to see where that takes us. If any of you are working a CLT project and want a consultant, I cant wait to be invited to support a CLT project.

In the meantime however, if you have any questions about firestop however please let me know. I am happy to help if I am able.

In closing I want to welcome a whole new crew from Utah to our blog posts. I was invited to do a class this past weekend. It was a great crew of guys and I had a lot of fun. I hope they learned a lot since they gave up their Saturday to hang out with me.  Welcome Utah crew!


All the best,