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The Critical Eye!

Michael Leavitt’s professional inspection related blog.

Firestop Collars on Garage Fire Separation Penetrations

Firestop Collars on Garage Fire Separation Penetrations

On January 21st of this year I composed a lengthy blog entry regarding a question that Sacramento, California Home Inspector Ken Ives had regarding garage fire separation wall penetrations’ Ken asked...

“Maybe I was on Maui for too long (if that is even possible), but I saw this today and it looked odd. PVC exhaust piping thru the ceiling of a garage.  Is this a fire wall compromise issue?” Ken Ives - Sacramento, CA -

Ives Firewall

I did a lot of research and thought I had come up with all of the right answers, until today. So flash forward 10 months and I received a call from another good friend and fellow Utah Home Inspector, Kurt Salomon. Kurt is one of the busiest radon mitigation contractors in Utah and he ran this scenario by me...

“Michael, I was put into the fire when I commented upon another radon mitigator’s work. I commented on the fact that he did not use a fire collar after he had bored a hole through the foundation footing to allow pipe access from the crawlspace to the garage and then again when he ran it out through the ceiling and roof.”

I listened to Kurt’s plight and envisioned what I thought he was talking about. In my ignorance I stated, “What good is one of those cheap metal collars going to do to protect a pipe going through solid concrete?”

Let me take a moment and show you what I thought Kurt was referring to in his description...

Bvent-Collar-4inch4inch B-vent Collar

I had reflected back on 18 years of inspecting homes in Northern Utah and this inappropriately used B-vent collar or some other metal ring is about all I ever see when either plastic radon or plastic 90+ PVC heater venting pipe penetrates the fire separation drywall. More often than not, I usually only see expanding spray foam. But in thruth, I never really gave any of this any thought because I have never heard anybody discuss it at any great length. And that is why researching topics is so much fun for me. I just love the discovery process, and I hope that you enjoy reading this lengthy, but informative blog entry about my findings.


3M-Fireblock-FoamI immediately went online to the Big Orange Box, and figured it would have all of the supplies needed regarding fire separation wall protective collars and/or sealants. I was wrong. They have a couple, but not what is really needed. Here are two products I found that come in easy homeowner applicator forms...

3M Fire Block Foam - $10.97 per can

DESCRIPTION - 3M Fire Block Foam FB-Foam is a ready-to-use foam firelock designed to help prevent the spread of flames and smoke in residential Type V and commercial non-rated construction. This product is intended to resist the free passage of flame and the by-products of combustion within the concealed space of a floor, ceiling or wall cavity by restricting the movement of air, fire and smoke. Also  acts as a draft stop to restrict air infiltration and movement. Meets current fire blocking sealant requirements of the  International Building Code (IBC) and International Residential Code (IRC) and state and local codes based on the IBC and IRC. 3M Fire Block Foam FB-Foam is recognized as a requirement to the methods prescribed by IBC and/or IRC codes for maintaining the  integrity of penetrations of fire blocking and for draft stopping.

    Heat-resistant up to 240° F (115° C)
    Ready-to-use (no mixing required)
    Tack-free in approximately 5 minutes
    Expands to quickly and effectively seal openings
    Sag-resistant formulation
    Minimal shrinkage
    MFG Model # : FB-Foam
    MFG Part # : FB-Foam

After reading the description, and seeing that it “Meets current fireblocking sealant requirements” in the IRC, one would assume this was perfect for the job. But just for fun, let’s keep looking...



DAP Fire Stop -  $29.97 for 2 tubes

The DAP Fire Stop 10.1 oz. Silicone Sealants (2-Pack) resist moisture, mold and mildew. This sealant is approved for sealing fire -rated service penetrations and construction joints in horizontal and vertical fire separations including steel and copper pipe, cables, concrete, gypsum wallboard and fiberglass pipe insulation.


    Water-based filler compound
    Single-component, neutral-cure, gun-grade, silicone fire-stopping sealant
    Classified for sealing fire-rated service penetrations and construction joints in horizontal and vertical fire separations including steel and copper pipe, cables, concrete, gypsum wallboard and fiberglass pipe insulation
    Tested for up to a 4-hour F-Rating at independent laboratories
    Resists fire and high heat
    Resists moisture, mold and mildew
    High-performance, elastomeric sealant remains flexible and is capable of up to 25% movement in fire-rated joints
    Meets ASTM E 814, UL 1479 and UL 2079 specifications
    Subject to or will include a recycling fee in the following states: CA, OR
    MFG Model # : 181244
    MFG Part # : 181244

Whoa, wait a minute. There seems to be an extreme limitation to this type of product. It is only for non-plastic type products. This was something I had never considered before... Is more needed for plastic pipe penetrations than for metal type penetrations?

What are we actually trying to do when we seal the fire separation wall penetrations, anyway? I think I need to re-read the International Residential Code. This time I will review the 2012 edition, because it went into effect here in Utah this past July, whereas my prior January research had my head in the 2009 IRC edition.


R302.5 Dwelling/garage opening/penetration protection.
Openings and penetrations through the walls or ceilings separating the dwelling from the garage shall be in accordance with Sections R302.5.1 through R302.5.3.

R302.5.1 Opening protection.
Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 13/8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 13/8 inches (35 mm) thick, or 20-minute fire-rated doors, equipped with a self-closing device.

R302.5.2 Duct penetration.
Ducts in the garage and ducts penetrating the walls or ceilings separating the dwelling from the garage shall be constructed of a minimum No. 26 gage (0.48 mm) sheet steel or other approved material and shall have no openings into the garage.

R302.5.3 Other penetrations.
Penetrations through the separation required in Section R302.6 shall be protected as required by Section R302.11, Item 4.

R302.6 Dwelling/garage fire separation.
The garage shall be separated as required by Table R302.6. Openings in garage walls shall comply with Section R302.5. This provision does not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.


For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

R302.11 Fireblocking.
In combustible construction, fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier between stories, and between a top story and the roof space.

Fireblocking shall be provided in wood-frame construction in the following locations:

    1. In concealed spaces of stud walls and partitions, including furred spaces and parallel rows of studs or staggered studs, asfollows:

    1.1. Vertically at the ceiling and floor levels.

    1.2. Horizontally at intervals not exceeding 10 feet (3048 mm).

    2. At all interconnections between concealed vertical and horizontal spaces such as occur at soffits, drop ceilings and cove ceilings.

    3. In concealed spaces between stair stringers at the top and bottom of the run. Enclosed spaces under stairs shall comply with Section R302.7.

    4. At openings around vents, pipes, ducts, cables and wires at ceiling and floor level, with an approved material to resist the free passage of flame and products of combustion. The material filling this annular space shall not be required to meet the ASTM E 136 requirements.

    5. For the fireblocking of chimneys and fireplaces, see Section R1003.19.

    6. Fireblocking of cornices of a two-family dwelling is required at the line of dwelling unit separation.

This got me to thinking about the different types of penetrations that I commonly see in garages. Occassionally I see the 90+ furnaces like Ken Ives shared, but much more common are the central vac installations and radon mitigation systems. Central vac systems have their thin walled PVC pipes penetrate the wall, and I rarely even see caulking, let alone anything more. My next researching step was to see what the central vac industry had to say on the topic. I found some great products and some explanations that really shed some great light on the fire separataion wall issue.

Here are some central vac install directions that stated in part...

“...Masonry or concrete walls.
If you have to run tubing through masonry or concrete walls, rent a hammer drill and/or masonry hole saw. Run the tubing through and patch the hole when installation is complete and system is running properly. Before drilling, check local building codes for special firewall penetration regulations. The code should tell you if steel tubing or firestop couplers are required for firewall penetration.”

I have never seen steel pipe used for the central vac or radon mitigation system penetrations, and what in the world are firestop couplers? I did more research and found two recommended methods for sealing the central vac lines where they penetrate the fire separations walls. It is interesting to note that neither option is readily available at your local home center.


  • Fire Barrier Plastic Pipe Tuck-In Wrap Strips 
  • Fire Barrier Plastic Pipe Collars

Let it be known that until today, I had no idea what either of these products were, what they accomplish, and that they are the only two acceptable and viable solutions when plastic piping penetrates fire separation walls. Here is what I stumbled upon and learned...

Fire Barrier Plastic Pipe Tuck-In Wrap Strips

First, I encountered this very informative online Q&A on a central vac site where there was a reported dispute with a Los Angeles, California building inspector who errantly denied the use of a product called, “The FireStop Ring” by STI. The “Tuck-In Wrap Strip” product was used and the inspector failed it by saying it was not a viable option under the current building codes...

STI-RingFireStop Ring by ST

Steel Pipe or Fire Stop?
Question:Hi folks, I was wondering if you know whether or not this particular product or the 3M product part#513F meets code in the city of Los Angeles? We were told by the city's inspector that we needed a metal collar around the PVC pipe fitting where it meets the ceiling of our garage, but this product as well as the 3M product seem superior in design and affect if called upon to protect our home... Thanks, Mark Oki
Answer:Hi Mark, historically it has been steel penetration but they also now accept the firestop method which does provide superior protection.

Here is a reply from STI Fire Stop's jhurley at, "The inspector is wrong.  They are asking for a traditional collar, which obviously works too, but a "wrapstrip tuck-in method" may be used also if there is a UL Classified Design.  Print out and provide the following UL System to the inspector, for STI's Central Vacuum Kit (STI Item# VPK-2) at this link: The local STI Rep is Mike Zanotelli and he can help with the paperwork for the inspector, his number is (310) 433-5398."



KEY POINT:A tuck-in wrap strip installation will barely be visible to the inspector. By the pictures you can see the installation gets tucked in and then covered with a bead of putty or caulk that conceals viewing the actual wrap strip. Take a look...


Vacuum Depot Link

Here are the 3M photos




“Okay”, you say, “But what difference does it make if the tuck-in wrap is installed or not? What does this do anyway? Who cares if it has just a bead of putty, caulk, spray-in foam, or if it has the tuck-in wrap installed? Is that all you are trying to do is just seal the joint between the pipe and the drywall?... I don’t get it!” Since those were my thoughts, I thought that you may have been thinking the same exact thing.

Fire Barrier Plastic Pipe Collars

Anybody who is still reading this finally gets to experience the “Aha Moment” with me as I discuss Plastic Pipe Fire Collars. These are often referred to as “Fire Couplers” and “Fire Collars” while always including the word “intumescent” in their descriptions.

Here is a picture of  a fire collar... Have you ever seen one?



Fire collars have metal cases and some type of rubber ring inside. Here is another view...



Still no “Aha Moment” for me, but I did get a Master Inspector paranoia moment because I had never remembered consciously seeing a firestop collar. If they are required, and I never realized it, then how many have I missed over the years? “Home Inspectors are not required to inspect central vacs anyway”, I reasoned. But we ARE responsible for reporting breeches in fire separation walls, and I could have been missing something important for the last 18 years. I took 2 hours to go through all of the pictures of the homes I have inspected in the last year, and guess what, I found images with firestop collars installed, even though it never actually registered as to what I was looking at in my cursory central vac evaluations. Let’s face it, when I see these systems I take my awl and cross the low voltage spade connections to energize the units to make sure that the motor comes on. I also report whether they vent to the exterior and how many sets of attachments I encounter. All of this greatly exceeds what our scope of inspection dictates, but I have never cared about the firewall penetrations, until now. This should have been of primary importance all along, and from this day forward it will.




Let’s read the information and find out more about Firestop Collars. They really are odd looking. And what is their purpose?...

Fire Barrier Plastic Pipe Collars

The Firestop Collar is a factory-manufactured device designed to protect plastic pipes penetrating fire-rated walls and floors. If  your central vacuum system pipe is going to run through a wall that is fire rated, this pipe could compromise the fire wall. The Firestop Coupler will serve to protect the integrity of the firewall when you are running pipe that penetrates the firewall.

Utilizing a heavy gauge galvanized metal collar to house a molded intumescent (swells when exposed to heat) insert, the Firestop Collar is specifically sized to fit 1-1/2½, 2½, 3½, and 4½ (38mm, 51mm, 76mm and 102 mm) trade sized pipes. When exposed to temperatures in excess of 320°F (160°C), the Collar’s molded insert begins to expand (intumesce) rapidly to form a dense, highly insulative char. Its free expansion ranges from 32-64 times original (pre-expanded) volume. Expansion continues up to 1,000°F (538°C).



    Rapid expansion: Closes off burning pipes quickly.
    Small profile: Use it in all the tight spots!
    Flexible & durable: No loose flakes (eye hazards).
    Water resistant: No water soluble or hygroscopic ingredients.
    Economical: Lower installed cost.
    High Volume Char: Expands up to 60 times!


Are you kidding me? These things expand up to 60 times and literally crush off the plastic pipe and seal it off from any smoke and/or fire flow. How cool is that? I never knew these existed. Look at the following photo...

UnexposedfirecollarLINK TO BLOG


Flashing back to my January discussion, fellow Home Inspector Darryll Piatt wrote...

Michael : Wow nice blog, very very informative. You‘re the man. So with Ken's question of the pvc exhaust and intake pipe, the below statement gives the answer.  So when the Brokers ask what the heck is approved material the only thing I have heard out of the whole disscussion and your blog is.....
..put an intumescent fire collar on it and you're done

R309.1.2 Other penetrations.
Penetrations through the separation required in Section R309.2 shall be protected by filling the opening around the penetrating item with approved material to resist the free passage of flame and products of combustion.

Darryl Piatt - Coos Bay, Oregon

Daryl is absolutely right, and he probably knew what an intumescent fire collar was when he responded. In my mind all I envisioned was a metal collar to help seal the penetrations.


  • 1) There is a big difference between the needs of metal piping and plastic piping as they penetrate fire separation walls.
  • 2) When metal pipe penetrates, then the 3M “3M Fire Block Foam” is a perfect $10.97 solution as it can be sprayed to fill the surrounding voids and there is no fear of the metal pipe melting down in a fire.
  • 3) When plastic piping penetrates a fire separation wall, then you need a device that will swell when heated and completely seal the pipe and prevent the spread of fire and smoke through an open melted pipe.
  • 4) This would include any plastic pipe that would allow the spread of fire and smoke if it melted open in a fire. I discussed the plastic heater vent pipes and radon mitigation systems, but also think about garage wash basin sink drains and laundry drains. Am I missing anything else?
  • 5) 2” pipe models of the fire collar or the fire ring run about $10-15 each.
  • 6) The 4” PVC pipe models of the fire collar that would need to be installed on radon mitigation systems run about $55. This means that if you installed them on both sides of the wall, then that would add $110 to the cost of a typical radon mitigation system. Is it any wonder why I never see them on radon systems?

    This is where YouTube can be so much fun. Here is a promotional video of a firestop collar in action. When you are done, you should type “fire collar” into the YouTube search engine and then sit back and enjoy...

    And if you want to go through a 6:31 training video... Enjoy!


  • I have once again been humbled to learn how much I don’t know, yet excited to learn about a “new to me” product. I have no idea whether I am alone in my prior ignorance, or if the majority of my fellow home inspectors are also unaware of how an intumescent fire collar or tuck-in wrap strip works. I will be very interested in the feedback I receive here in this blog regarding the topic. I would love for you to shoot straight with me and share your prior level of understanding or ignorance. My fear is that most will read, gleen, and then act as though they already knew the information all along.



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