PVC in fire rated assembly.

[mtlogcabin]

Depending on both the material being penetrated and the penetrating material, simple "fire caulk" alone may or may not (probably not) be enough

Lubrizol (Orange) PVC fire sprinkler pipe is an example of where incompatible materials in contact with each other may cause pipe failure years down the road.

Incompatible Products - Lubrizol

Lubrizol recommends that the compatibility of ancillary products be confirmed with that product’s manufacturer prior to use. The following products have been found to be incompatible with FlowGuard, BlazeMaster, Corzan, and products made with TempRite® Technology.

www.lubrizol.com

To avoid damage to the pipe and fittings, ancillary construction products coming into direct contact with FlowGuard®, BlazeMaster®, Corzan®, or products made with TempRite® Technology must be chemically compatible. Lubrizol recommends that the compatibility of ancillary products be confirmed with that product’s manufacturer prior to use.

The following products have been found to be incompatible with FlowGuard, BlazeMaster, Corzan, and products made with TempRite Technology. Please note: a product’s absence from this list does not mean that it is compatible. Products in this list are designated with numerals to clarify the reason they are listed as incompatible. The numerical designations are defined as follows:

 

[steveray]

Sorry, thinking like a tinner again. Duct penetrations only need protection if they are full through penetrations or penetrate the ceiling membrane of the assembly, not at the floor.

I'm going to say incorrect....it is a membrane penetration of a listed assembly and needs to be treated as such....We all know fire does not burn down, but...A listed assembly is a listed assembly...

 

[klarenbeek]

I'm going to say incorrect....it is a membrane penetration of a listed assembly and needs to be treated as such....We all know fire does not burn down, but...A listed assembly is a listed assembly...

2021 IMC 607.6.2 Membrane Penetrations. Ducts and air transfer openings constructed of approved materials, in accordance with Section 603, that penetrate the ceiling membrane of a fire-resistance-rated floor/ceiling or roof/ceiling assembly shall be protected with one of the following: .........

Through penetrations are covered in 607.6.1. Nowhere does it say duct that penetrates the floor membrane only needs to be protected. There's no damper or other assembly that I know of that's listed for that application. I see this all the time in apartments with a downflow air handler with the duct running through the trusses of the floor/ ceiling assembly then turning back up to floor registers.

 

[steveray]

714.5.2 Membrane Penetrations​

Diagram
Penetrations of membranes that are part of a horizontal assembly shall comply with Section 714.5.1.1 or 714.5.1.2. Where floor/ceiling assemblies are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.
Exceptions:

1. Membrane penetrations by steel, ferrous or copper conduits, pipes, tubes or vents, or concrete or masonry items where the annular space is protected either in accordance with Section 714.5.1 or to prevent the free passage of flame and the products of combustion. The aggregate area of the openings through the membrane shall not exceed 100 square inches (64 500 mm2) in any 100 square feet (9.3 m2) of ceiling area in assemblies tested without penetrations.

714.5.1.1 Fire-Resistance-Rated Assemblies​

Through penetrations shall be protected using systems installed as tested in the approved fire-resistance-rated assembly.

714.5.1.2 Through-Penetration Firestop System​

Through penetrations shall be protected by an approved through-penetration firestop system installed and tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch of water (2.49 Pa). The system shall have an F rating/T rating of not less than 1 hour but not less than the required rating of the floor penetrated.

 

[mtlogcabin]

Floor/ceiling and roof/ceiling assemblies are rated from below at the ceiling.

722.6.2.1 Fire-resistance rating of wood frame assemblies.
The fire-resistance rating of a wood frame assembly is equal to the sum of the time assigned to the membrane on the fire-exposed side, the time assigned to the framing members and the time assigned for additional contribution by other protective measures such as insulation. The membrane on the unexposed side shall not be included in determining the fire resistance of the assembly.

722.6.2.4 Floors and roofs.
In the case of a floor or roof, the standard test provides only for testing for fire exposure from below. Except as noted in Section 703.3, Item 5, floor or roof assemblies wood framing shall have an upper membrane consisting of a subfloor and finished floor conforming to Table 722.6.2(4) or any other membrane that has a contribution to fire resistance of not less than 15 minutes in Table 722.6.2(1).

 

[klarenbeek]

714.5.2 Membrane Penetrations​

Diagram
Penetrations of membranes that are part of a horizontal assembly shall comply with Section 714.5.1.1 or 714.5.1.2. Where floor/ceiling assemblies are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.
Exceptions:

1. Membrane penetrations by steel, ferrous or copper conduits, pipes, tubes or vents, or concrete or masonry items where the annular space is protected either in accordance with Section 714.5.1 or to prevent the free passage of flame and the products of combustion. The aggregate area of the openings through the membrane shall not exceed 100 square inches (64 500 mm2) in any 100 square feet (9.3 m2) of ceiling area in assemblies tested without penetrations.

714.5.1.1 Fire-Resistance-Rated Assemblies​

Through penetrations shall be protected using systems installed as tested in the approved fire-resistance-rated assembly.

714.5.1.2 Through-Penetration Firestop System​

Through penetrations shall be protected by an approved through-penetration firestop system installed and tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch of water (2.49 Pa). The system shall have an F rating/T rating of not less than 1 hour but not less than the required rating of the floor penetrated.

Ducts are not covered by this section. In the IBC they are covered in section 717. Through penetrations of horizontal assemblies are covered in 717.6 which reads the exact same as IMC 607.6. IBC 717 and IMC 607 are basically identical for a reason.

 

[Penguin87]

No. This is a gross over-simplification. The closure must be a listed penetration seal assembly. Depending on both the material being penetrated and the penetrating material, simple "fire caulk" alone may or may not (probably not) be enough. IBC 2021:

Its not "fire caulk," HILTI and other manufacturers have testing reports that you can submit for your assembly type. These are UL tested firestop systems, if installed as per the directions of the manufacturer.

 

[Penguin87]

Floor/ceiling and roof/ceiling assemblies are rated from below at the ceiling.

722.6.2.1 Fire-resistance rating of wood frame assemblies.
The fire-resistance rating of a wood frame assembly is equal to the sum of the time assigned to the membrane on the fire-exposed side, the time assigned to the framing members and the time assigned for additional contribution by other protective measures such as insulation. The membrane on the unexposed side shall not be included in determining the fire resistance of the assembly.

722.6.2.4 Floors and roofs.
In the case of a floor or roof, the standard test provides only for testing for fire exposure from below. Except as noted in Section 703.3, Item 5, floor or roof assemblies wood framing shall have an upper membrane consisting of a subfloor and finished floor conforming to Table 722.6.2(4) or any other membrane that has a contribution to fire resistance of not less than 15 minutes in Table 722.6.2(1).

While true, many tested horizontal assemblies derive their fire resistance in the char rate of the wood joists. Ie, UL L501.
In my experience most jurisdictions won't accept a fire rating unless its either a tested assembly or one you calculate using table 722.6.2(1)

 

[Yankee Chronicler]

Its not "fire caulk," HILTI and other manufacturers have testing reports that you can submit for your assembly type. These are UL tested firestop systems, if installed as per the directions of the manufacturer.

Then it has to be drawn and specified exactly as required by the manufacturer's directions, and it must be shown somewhere on the drawings or in the specifications that it is a listed assembly. You can't just specify Hilti XYZ123 and leave it to the worker in the field to decide how much annular space to leave, and how much good to squeeze into the annular space.

Many penetration seals, including many using Hilti products, require a mineral wool backer. Others require a metal sleeve. Some require both a sleeve and a mineral wool backer. That's why I said your original statement was an oversimplification. As written, it suggests is that all you need as some Hilti goop and you're good to go.

 

[steveray]

Ducts are not covered by this section. In the IBC they are covered in section 717. Through penetrations of horizontal assemblies are covered in 717.6 which reads the exact same as IMC 607.6. IBC 717 and IMC 607 are basically identical for a reason.

And 717 sends you back to 714....? And maybe we are agreeing but looking at different requirements relating to shafts or dampers or whatever?​

717.1.2 Ducts That Penetrate Fire-Resistance-Rated Assemblies Without Dampers​

Ducts that penetrate fire-resistance-rated walls and are not required by this section to have fire dampers shall comply with the requirements of Sections 714.3 through 714.4.3. Ducts that penetrate horizontal assemblies not required to be contained within a shaft and not required by this section to have fire dampers shall comply with the requirements of Sections 714.5 through 714.6.2.

 

[klarenbeek]

So what would protection of a duct penetration of a floor-membrane-only consist of? The drywall on the bottom is never penetrated so its not a full through penetration. This design is used extensively in wood frame apartment buildings. There are no listed products that I know of for this application. The other problem is most of 714.5 through 714.6.2 covers very specific types of penetrations, none of which are ducts.

Its a stretch, but maybe register flanges at the individual runs and the air handler itself at that location meet this exception to 714.5.2??
"Membrane penetrations by steel, ferrous or copper conduits, pipes, tubes or vents, or concrete or masonry items where the annular space is protected either in accordance with Section 714.5.1 or to prevent the free passage of flame and the products of combustion."

Problem with this is again specific items are listed, none of which are duct.

Maybe getting off track here from the OP.... sorry

 

[Penguin87]

So what would protection of a duct penetration of a floor-membrane-only consist of? The drywall on the bottom is never penetrated so its not a full through penetration. This design is used extensively in wood frame apartment buildings. There are no listed products that I know of for this application. The other problem is most of 714.5 through 714.6.2 covers very specific types of penetrations, none of which are ducts.

Its a stretch, but maybe register flanges at the individual runs and the air handler itself at that location meet this exception to 714.5.2??
"Membrane penetrations by steel, ferrous or copper conduits, pipes, tubes or vents, or concrete or masonry items where the annular space is protected either in accordance with Section 714.5.1 or to prevent the free passage of flame and the products of combustion."

Problem with this is again specific items are listed, none of which are duct.

Maybe getting off track here from the OP.... sorry

You would need a design professional to review the project specifics, as-built condition and applicable codes.

 

[Yankee Chronicler]

So what would protection of a duct penetration of a floor-membrane-only consist of? The drywall on the bottom is never penetrated so its not a full through penetration. This design is used extensively in wood frame apartment buildings. There are no listed products that I know of for this application. The other problem is most of 714.5 through 714.6.2 covers very specific types of penetrations, none of which are ducts.

Its a stretch, but maybe register flanges at the individual runs and the air handler itself at that location meet this exception to 714.5.2??
"Membrane penetrations by steel, ferrous or copper conduits, pipes, tubes or vents, or concrete or masonry items where the annular space is protected either in accordance with Section 714.5.1 or to prevent the free passage of flame and the products of combustion."

Problem with this is again specific items are listed, none of which are duct.

Maybe getting off track here from the OP.... sorry

IBC 714.5.1 addresses through penetrations, so there's no pint in even looking at that for an answer to your question about penetrating only the upper membrane of a horizontal assembly. You need to be looking at 714.5.2.

See 714.5.2, Exception #1. I would consider a steel duct with a floor register to be a "vent."

 

[klarenbeek]

See 714.5.2, Exception #1. I would consider a steel duct with a floor register to be a "vent."

A duct is NOT a vent. Both the IMC and IFGC have a very specific definition of "vent":
"A pipe or other conduit composed of factory-made components, containing a passageway for conveying combustion products and air to the atmosphere, listed and labeled for use with a specific type or class of appliance."

Both codes have an entire chapter dedicated specifically to "vents". Ducts are covered in a separate chapter in the IMC, so no, the heat run with a floor register is NOT a vent.

 

[Yankee Chronicler]

A duct is NOT a vent. Both the IMC and IFGC have a very specific definition of "vent":
"A pipe or other conduit composed of factory-made components, containing a passageway for conveying combustion products and air to the atmosphere, listed and labeled for use with a specific type or class of appliance."

Both codes have an entire chapter dedicated specifically to "vents". Ducts are covered in a separate chapter in the IMC, so no, the heat run with a floor register is NOT a vent.

I sit corrected.

IMC 2021:

VENT. A pipe or other conduit composed of factory-made
components, containing a passageway for conveying
combustion products and air to the atmosphere, listed and
labeled for use with a specific type or class of appliance