Why is special inspection of firestop now required?

Are these building code changes going to impact your next project?

(Round 2 why the code changed)

Some of you are thinking, “ The building inspectors already look at the firestop.” Or maybe you are thinking, “It’s not that complicated.” If you look at ASTM E2174, which is the standard for third party inspection of firestop through penetrations and talk to an inspector about what is required to comply with an inspection at this level, most building officials will tell you they do not have the time for that. Some will even admit they don’t have the training to look at it adequately. Combine that, with the fact that some jurisdictions with strong local third party inspection firms have reported that the failure rate on most projects the first few inspections is generally around 50%. That is typical, which means of course some project teams are stronger, but it also means that some are failing inspections well over half the time. Now, to understand that better, you have to look at what goes into as ASTM E 2174 inspection.


First the inspector needs to do one of two types of inspection. They either need to witness the inspection on 10% of each type of installation type or they need to conduct destructive testing on 2% of each type. When inspecting a firestop installation the following items must be reviewed by the inspector and they must confirm that each item conforms to the submitted and approved firestop assembly. That assembly must be tested and listed with a third party agency (most commonly Underwriters Laboratories or UL). When conducting an inspection according to this standard all of these elements must be reviewed. Each line here could warrant a series of blog posts because there is so much more information that needs to be known than what is just written here, but this is a decent start at least:rated assembly-to ensure it conforms with what is allowed in firestop details:

  • rated assembly-to ensure it conforms with what is allowed in firestop details
    • stud depth is a critical often overlooked component
  • penetrating item- to ensure they match in material, size etc
    • changes in material or size can have a major impact
  • sleeve- is it allowed, required or optional
  • insulation- to ensure both material and thickness conform
  • type of firestop material – manufacturer and material name
    • not all firestop is the same, even from the same manufacturer
  • annular space- minimum and maximum
    • both are very important and must be conformed to
  • sealant depth and any required bead of sealant
    • this requires an entirely different discussion
  • backing material- type, depth and compression
    • all three can be critical
  • square ducts over a certain size require retaining angle
  • plastic pipe over a certain size it requires a firestop collar
    • collars require washers and anchor type will vary based on substrate
    • plastic pipe over another size requires all that plus foil tape


You want your project being inspected by someone who knows how to look at each of these elements to confirm it conforms to the firestop details. You also want them to know WHY each is critical to the life safety of a building. If they can share this information with the team during the mandatory pre-construction meeting it has a tendency to increase the perceived level of importance for the entire team and may even increase team collaboration.  HLS pre-con meetings have been called “A GAME CHANGER” by some of our project teams.


If your project is hiring a third party inspection firm who does everything under the sun, including firestop and you want to know whether or not you are getting what you are paying for, contact us and we will help you make sure that your project is actually complying with the requirements of the codes and standards. You may be surprised by everything they should be doing.

Stair 4

When people build gypsum walls around stair enclosures there are an array of issues that can arise.  The one that concerns me the most is that you have a head of wall joint and a bottom of wall joint at EVERY floor. 

There is no way to get traditional firestop sealants and sprays behind the stair runner. 

This means you will have about 18 inches at the top and bottom of the wall on every floor, on each side of the stairs where your firestop will not be installed. 

Tomorrow I will explain another reason I don’t like exit shafts made of gypsum board.

#BuildBetter #FirestopCoffeeBreakTraining

Stair 3

Block walls are my second favorite type of walls for an exit shaft. Second to concrete because the block wall sits on the concrete floor and it will need to be firestopped at the top of the wall. 

This is done after the stairs are installed. If it’s not done properly any breach which could mean fire and smoke could enter the exit stairs. 

Here is your weak point ~ When the stair stringer runs against the floor slab, how is anyone going to install firestop in the top of wall joint behind the stair stringer?

If you deal with this, what is your solution?

Tomorrow I will tell you why I hate gypsum walls for exit stair enclosure. In the meantime, let me know what you think.

#BuildBetter #FirestopCoffeeBreakTraining

Stair 2

If you have to design or build an exit stair shaft, what do you build the walls out of and why?

My favorite type of stairs are solid concrete because there are no joints. There is no opportunity for fire or smoke to get through where the wall transitions from one floor to the next. 

What are your thoughts on that? Is that how you design or build? If not, why not?

Tomorrow I will tell you why I’m not a fan of block walls in exit stairs. 

#BuildBetter #FirestopCoffeeBreakTraining

Stair 1

Stairs are a critical element of life safety in any building. Here are three reasons they are so important

  1. It is the way building occupants escape in an emergency. 
  2. It is the way first responders get in to fight a fire and rescue people
  3. It is an area of refuge for those who cant evacuate. Imagine being in a high rise and being immobile. This would be your safe place
  4. They are a safe haven for fire fighters when the world is falling apart

If you build buildings, you MUST build them right. If you design buildings, how do you choose from your various options?  Concrete, block drywall. How do you pick one over the other? If you stay with me this week, you may reconsider your choices.

#BuildBetter #FirestopCoffeeBreakTraining

For a Building Official with some Great Questions

This video is my response to him. I hope it he

In my classes I often invite people to stay in touch and ask questions when they have some. Here is a video I created in response to some questions from a building official. I hope it helps you too. https://youtu.be/VSooTd4rLN0

Why there is no promise that your one hour rated wall will last for one hour in a fire.

Before Covid I did a lot of training classes. One day in class I had a guy get mad at me when I told him there was no promise that a one hour rated wall would survive a fire for one hour. Talk about shoot the messenger! But understanding this is important for anyone who designs builds or inspects. That is the topic of this “Firestop Coffee Break Training”. Please join me.