Welcome back to our Lessons in Firestop! In our first lesson, you learned the six critical steps to reduce firestop headaches on your projects, and we explained half of them. Hopefully you also spent some time with the firestop coffee break training I shared with you. If you did, you are armed with a secret weapon that only those who know firestop really understand. In our next lesson I will show you a few tricks with which you can use that information. They are kind of like magic tricks, but I will explain later.
In this lesson I want to explain the last three steps of your planning process. If you remember, the steps are:
- Determine your floor assembly or assemblies.
- Determine your wall assemblies.
- Determine your penetrations.
- Find your UL details.
- Determine your annular space.
- Plan your openings.
The first three steps are like a shopping list. Imagine you are having a party or going on a camping trip. You might make a list of things you need. That is steps one, two, and three. Step four is the actual shopping. If you haven’t learned your ABCs and 123s, this next part might get confusing, so feel free to go back and check that out so you can follow along.
Let’s imagine you have a podium-style project with a concrete parking area and shops on the lower levels and wood-framed, or even Hambro style, floors/ceilings above. That takes care of step one. From step two, you determine that you have block stair shafts, gypsum elevator shafts, and two-hour demising walls. In step three you make a chart of all of the different details needed, so in step four you are going to find the firestop details for each different application.
Let’s start with our podium. If you are coring your holes, you probably will use CAJ details for the list of different penetrations through the concrete floor, and you can use those for the block walls as well.
If you are running sleeves for your floors, I highly recommend you consider using cast-in-place devices, because if you are going to take all of that time doing the layout, you might as well save time later and not have to deal with firestop sealants and mineral wool. If you have used those, jump in the comments and let everyone know what you think. They have pros and cons. For example, if you can’t lay out sleeves well, don’t bother with cast-in-place devices, but if you get them in the right spot most of the time, it’s time to take advantage of a better solution. We will get into that in a future segment to help you see the pros and cons and the wide array of products to consider.
Next you have to work through the same process for the floor system that you will have above the podium level. Then you need to do the same process again with all of the different wall types. I will admit there is a lot to this, so if you need help the first time just let me know and I am happy to help.
Steps Five and Six
Once you get a list of all of the different applications that will need firestop and you have a firestop detail for all of the applications, it is time to start planning. You need to know what size holes to make in the different fire-rated assemblies.
If you are running ¾-inch PVC pipe for example, you likely know that the OD of the pipe is just more than 1 inch. Clearly, a 1-inch opening is not going to be quite enough for the pipe to fit.
I was on a project recently that reminded me of Goldilocks and the Three Bears. Do you remember that story? One porridge was too hot, one was too cold, and the other was just right. Well, firestopping plastic pipes can be very much like that. On this project, I assume they had three drills and one pack of drill bits or hole saws. This was a wood-framed project so the firestop details required ¾-inch depth of sealant around the plastic pipes. The first hole was too small; the pipe fit nice and snug, but there was no space for the firestop. Another hole was too big; they could get firestop in the opening, but it was more annular space than what was allowed by the firestop detail. The third opening was just right; there was enough space to get the pipe in easily, they could get the required ¾-inch depth of sealant in, and it was within the parameters of the UL detail they submitted.
For those who have had a project where this happened, in a future lesson we will walk through the solutions for our Goldilocks problem.
So, for step five, I literally print out (or load into my iPad) all of the firestop details. Then I highlight the annular space and put the required opening size in a new line on the chart we made in step three. I give that to the field teams, and if they follow this guide they are going to reduce firestop headaches considerably.
I should also tell you that a code change is coming in the 2021 International Building Code (IBC), and when your jurisdiction adopts it, you might want to be sure you have this planning process working smoothly on every project so you don’t end up in trouble. We will talk about that as well, so keep checking back for more valuable information designed to help you build better.
Remember, our Lessons in Firestop are designed to help you build better, so if there is a topic you want covered, please let me know. If you have photos or examples that you think will help others build better, let’s share them!
Connect with Sharron
A former kindergarten teacher turned firestop expert, Sharron is President of Halpert Life Safety Consulting LLC, a leading provider of firestop-related life-safety and passive fire protection solutions.
If you like what you read here and want to know more, email [email protected] or connect with her on LinkedIn or Twitter to tell her what else you want her to cover in this column. You can also follow her on Instagram. If you find this information valuable, please like, share, comment, repost, retweet, and throw it on IG to help people build better.
The opinions expressed in this article are those of the author and not the American Society of Plumbing Engineers.