The horror story I shared with you last month is something that has left some people with sleepless nights and budgets that are completely shot. On the other hand, for some people this is a common occurrence, so they may not have any issues whatsoever. However, if there was ever a fire in that building and the insurance investigators know to take a closer look at the construction, it wouldn’t be difficult for an educated individual to see that the fire made it through floors and walls prematurely.
Don’t think that your statute of limitations will save you after a certain date on the calendar, because if you think about the Surfside condo that collapsed in Miami one year ago, everyone is getting dragged back into that legal battle now.
Thus, the goal of this firestop lesson is not to scare you into submission. If you have been joining us here for the last few months, then I assume you are the sort of person who wants to build right. It doesn’t matter if your team installs the firestop or if you leave that to the firestop specialty contractors—either way, you as the plumbing engineer are responsible for providing the firestop installer with an application that can be properly firestopped. Don’t think that because you bid out the firestop, you are off the hook.
In this lesson I want to autopsy this horror story so you understand what really went into resolving the firestop issue.
The first version is when the birds are singing, the sun is shining, and all is well with the world. We have a 2-inch hole created for a 1-inch plastic pipe that has an outside diameter of roughly 1¼ inches. If the field team made a 2-inch opening, they will have 3/8 inch if the pipe is centered and a bit more and a bit less if it is not centered. The firestop detail requires a minimum ¼-inch/maximum ¾-inch annular space. It also requires ¾ inch depth of sealant at the floor, which is also called the sole plate. Then it requires 5/8 inch depth of sealant at the top plate, which is the top of the framing for the wall below the floor.
If the firestop installer is on the third floor, they are typically going to firestop the floor of the floor ceiling assembly on the third floor as well as the ceiling of the fourth floor’s floor ceiling assembly, so this is what it will look like: The installer will find the 1-inch plastic pipe, then go down on one knee and work from that position on the floor to install the firestop at the subfloor. If they have just under ½ inch of annular space, it will be easy to get the required ¾ inch of sealant. Then they grab a ladder and put sealant on the top side of the top plate at the ceiling level, and they are done.
On the other hand, if no annular space is available for the sealant because the hole was cut too tight, then there are two choices.
The wrong choice is that the installer just smears sealant around the opening to make it look like it is firestopped. Just because someone smears firestop material around, that doesn’t mean you have met the requirements of the code even if the inspector doesn’t call you out on it. If this happens on your project, you have a massive liability. In our second Lessons in Firestop, I hinted that code changes are coming that you need to know about, and we will tackle that in our very next Lessons in Firestop segment. For now, however, DO NOT let your teams do this.
Let’s assume the inspector caught your installers and called them out on not being able to properly firestop the application with this small opening and no annular space.
Now What Do You Do?
First, reach out to your firestop manufacturer to find out what they propose as a solution. That means you will need to get an engineering judgement, otherwise known as an EJ. This will show the installers how to install the collars I previously mentioned in the last lesson. That will need to be approved by the building official as well as the architect.
Then it will be time to install this tiny firestop collar. The field crews will have to spend some time fabricating the collars. Then they have to install a collar on the underside of the top plate where the ceiling will go, but they will have to get a ladder tall enough to get them to the underside of the subfloor so they can install a collar on the underside. This will ensure that if a fire occurs, the opening that the pipe is going through will close down when the plastic pipe burns away. This collar will need to be fastened with screws and maybe even washers, so all of this comes together to cost you considerably more money if you are going to build right. If you chose to not build right, it will cause considerably more liability.
Some of you may think that a small pipe is just causing a small problem, but take a moment and listen to a discussion about properly installed firestop where Bruce Johnson of UL (who tests firestop installations) tells us that “even the smallest void that is not protected with proper firestopping almost acts like a blow torch.”
Please remember that even when you hire a firestop specialty contractor, you are still responsible for the openings that your pipes run through. Now with the information in the last few lessons, you know how to plan your project for success, and you know one horror story to avoid. However, there are so many more things that are important if you want to get this right, and we will get to all of them in time.
In our next Lessons in Firestop, I want to talk to you about a few building code changes that could be impacting you. I’d also love to hear from you to know what else you’d like to hear about. If there is a particular topic you want us to discuss, please email your favorite ASPE staff, or you can reach out to me directly at [email protected]. Either way, see you there!
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.