PVC in fire rated assembly.

[Fast_Edd1e]

I have a mixed use project in michigan using MBC 2015. Lower level is business, upper is R-2 apartments. V5 construction with wood floor trusses. With full fire suppression we only need a 1/2 hour separating. We are getting told that we are not allowed to use pvc in the rated floor/ceiling assembly. This would be all of our sanitary lines and such for the apartments. Our floor/ceiling is 1.5" gyp crete, 3/4" sheathing, 24" deep wood truss, rc channel and 5/8" gpp on underside.

We have done this numerous time and just used fire caulk or such where pipe penetrates thru. But we are being told that any penetration has to be metal pipe.

Is there a code section i can reference to allow this? Everything im being told is its never been flagged at other jurisdictions and no one does metal pipe anymore.

Im hoping to use section 722 for Calculated Fire resistance and say that the 1.5" gypcrete works as a separation from the apartment and the 5/8" gyp on the underside as well. Instead of calling it an "assembly" since its only needed to be 1/2 hour rating.

To add to this. I believe it is possible because im seeing details on Hilti website for "plastic pipe thru gypsum". But im being told i need to show a code section to allow it.

 

[steveray]

Horizontal assemblies/ penetrations is like 714.5 (2021) ...If someone is actually insisting that you can't have combustible pipes in a combustible rated floor, they need to be fired.....

 

[Fast_Edd1e]

Horizontal assemblies/ penetrations is like 714.5 (2021) ...If someone is actually insisting that you can't have combustible pipes in a combustible rated floor, they need to be fired.....

For example. The attached picture. This passed another jurisdiction. They are saying that all of these pipes need to be steel. Or where they pass thru the floor or ceiling membrane need to be steel. Which would mean your floor flanges for your toilet would need to be steel since it wont extend 6" above the floor membrane.

Could you possibly explain 714.5 a bit more. Because that is for penetrations thru Non-fire resistance rated assemblys. Where our floor is a ul L521.

 

[Fast_Edd1e]

Horizontal assemblies/ penetrations is like 714.5 (2021) ...If someone is actually insisting that you can't have combustible pipes in a combustible rated floor, they need to be fired.....

To add to this. He is referencing section 714.4 (2015) horizontal assemblies. Saying that we have to use exception #1 requiring them to be metal.

 

[steveray]

A penetration, by definition, runs through the assembly.....(If it is a through penetration anyway)....and there are several ways to allow and protect them.....

714.5 Horizontal Assemblies​

Diagram
Penetrations of a fire-resistance-rated floor, floor/ceiling assembly or the ceiling membrane of a roof/ceiling assembly not required to be enclosed in a shaft by Section 712.1 shall be protected in accordance with Sections 714.5.1 through 714.5.4.

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.

 

[Fast_Edd1e]

A penetration, by definition, runs through the assembly.....(If it is a through penetration anyway)....and there are several ways to allow and protect them.....​

​

714.5 Horizontal Assemblies​

Diagram
Penetrations of a fire-resistance-rated floor, floor/ceiling assembly or the ceiling membrane of a roof/ceiling assembly not required to be enclosed in a shaft by Section 712.1 shall be protected in accordance with Sections 714.5.1 through 714.5.4.

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.

Perfect.
That is what I had just researched. That these HILTI systems have the UL 1479 testing. So PVC is required, it just has to have the appropriate firestop system.

 

[Yankee Chronicler]

Keep in mind the distinction between through penetrations and membrane penetrations.

Where a vertical pipe passes straight through the top and the bottom iof a floor/ceiling assembly (or horizontally all the way through a wall assembly), that's a through penetration, and those require penetration seal assemblies tested and listed for through penetrations.

Where a pipe passes through the top or bottom of a floor/ceiling assembly (or one face of a wall) and then turns 90 degrees to run within the assembly, that's a membrane penetration and requires penetration seals tested and listed for penetration seals.

714.4.2 Membrane penetrations. Membrane penetrations
shall comply with Section 714.4.1. Where walls or partitions
are required to have a fire-resistance rating, recessed fixtures
shall be installed such that the required fire resistance will not
be reduced.

There's a lengthy list of exceptions under 714.4.2. I won't reproduce them all -- but be sure to read them. The Commentary for 714.4.2 is also lengthy, so I'll only reproduce the opening paragraph:

“Membrane penetration” is defined in Section 202 as
“a breach in one side of a floor/ceiling, roof/ceiling or
wall assembly to accommodate an item installed into
or passing through the breach.” Therefore, they are
different from a through penetration in that they do not
pass through the entire assembly. Membrane penetrations
are treated similarly to through penetrations.
Specifically, noncombustible conduits, pipes and tubes
that penetrate only one membrane of a fire-resistancerated
wall assembly are required to have the annular
space protected in accordance with Section 714.4.1 or
comply with the exception of that section. Combustible
penetrations through only one membrane of a wall
assembly would require either a tested assembly (see
Section 714.4.1.1) or a through-penetration firestop
system that complies with Section 714.4.1.2 for the
penetrated membrane.

 

[ICE]

I,m confused (no surprise) I looked at the pictures and did not see any membrane or through penetrations. I did see plenty of PVC. Hilti in-tumescent rings solve issues.

I take it back, I found one:

 

[Yankee Chronicler]

I,m confused (no surprise) I looked at the pictures and did not see any membrane or through penetrations. I did see plenty of PVC. Hilti in-tumescent rings solve issues.

I take it back, I found one:

View attachment 14042

Looks like a couple of PEX lines also run up through the floor just to the right of the clip you reproduced.

 

[Fast_Edd1e]

Keep in mind the distinction between through penetrations and membrane penetrations.

Where a vertical pipe passes straight through the top and the bottom iof a floor/ceiling assembly (or horizontally all the way through a wall assembly), that's a through penetration, and those require penetration seal assemblies tested and listed for through penetrations.

Where a pipe passes through the top or bottom of a floor/ceiling assembly (or one face of a wall) and then turns 90 degrees to run within the assembly, that's a membrane penetration and requires penetration seals tested and listed for penetration seals.



There's a lengthy list of exceptions under 714.4.2. I won't reproduce them all -- but be sure to read them. The Commentary for 714.4.2 is also lengthy, so I'll only reproduce the opening paragraph:

I had looked at this because that is originally what the inspector was quoting. But the first part of that. Membrane section directly references through penetrations first. Then the other exceptions reference electrical boxes. He was hung up that since it didn't mentioned pipe, we cant penetrate one side of the assembly. Which i thought was absurd.

 

[klarenbeek]

Ask him for the code section that says you can't penetrate just the top side of the assembly, since it's not a membrane or through penetration.

 

[Dinheru]

Isnt PVC non-combustible? and therefor anywhere allowed? Especially in type V construction?
Unless going through stairs or fire rated enclosures I always interpreted the following way
MEP is allowed to penetrate through pretty much anywhere because they are non combustible. in case of HVAC you would have air transmission, which firedamper stops that
If electric wires could have been made of rope, and water drain lines made of wood. It would be obviously not be allowed due to combustible.
Fire caulking I would think is sufficient

1023.5 Stair penetration is a different story

 

[BN4537]

Isnt PVC non-combustible? and therefor anywhere allowed? Especially in type V construction?
Unless going through stairs or fire rated enclosures I always interpreted the following way
MEP is allowed to penetrate through pretty much anywhere because they are non combustible. in case of HVAC you would have air transmission, which firedamper stops that
If electric wires could have been made of rope, and water drain lines made of wood. It would be obviously not be allowed due to combustible.
Fire caulking I would think is sufficient

1023.5 Stair penetration is a different story

NFPA EFFECT

Combustible material

A material that, in the form in which it is used and under the conditions anticipated, will ignite and burn; a material that does not meet the definition of non-combustible or limited-combustible.

Non-combustible material

A material that complies with any one of the following shall be considered a non-combustible material:

1. The material, in the form in which it is used, and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat.
2. The material is reported as passing ASTM E 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 °C.
3. The material is reported as complying with the pass/fail criteria of ASTM E 136 when tested in accordance with the test method and procedure in ASTM E 2652, Standard Test Method for Behavior of Materials in a Tube Furnace with a Cone-shaped Airflow Stabilizer, at 750 °C.

or

A material that is classified as A1 by the EN 13501-1 test series.

Pretty much everything aside from concrete and steel is considered combustible. 750 degrees C is approximately 1382 degrees Fahrenheit.

 

[BN4537]

PVC burns much like a marshmallow over a camp fire, if you try to bend PVC conduit with a heat gun and heat it too long you will see what I mean.

 

[tmurray]

To be fair, it's not like there is anything else combustible in that cavity. <sarcasm>

 

[Paul Sweet]

Seeing the orange sprinkler piping makes me think the truss space needs to be sprinklered since the lower level is business which requires a NFPA 13 system.

 

[mtlogcabin]

714.5.2 Membrane penetrations.
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.

The answer is in 714.5.1.1 it covers all penetrations and all materials

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.

 

[Yankee Chronicler]

Ask him for the code section that says you can't penetrate just the top side of the assembly, since it's not a membrane or through penetration.

Penetrating the top (floor) side of a floor-ceiling assembly IS a membrane penetration, and requires a listed penetration seal assembly if the floor-ceiling assembly is fire-resistance rated.

 

[steveray]

Isnt PVC non-combustible?

No...maybe limited combustible but not non....Just like FRTW......

 

[mtlogcabin]

Type I and II construction are the only construction Types that limit combustible materials for construction of a building.

 

[steveray]

Type I and II construction are the only construction Types that limit combustible materials for construction of a building.

And even then there is this:

718.5 Combustible Materials in Concealed Spaces in Type I or II Construction​

Diagram
Combustible materials shall not be permitted in concealed spaces of buildings of Type I or II construction.
Exceptions:

1. Combustible materials in accordance with Section 603.
2. Combustible materials exposed within plenums complying with Section 602 of the International Mechanical Code.
3. Class A interior finish materials classified in accordance with Section 803.
4. Combustible piping within partitions or shaft enclosures installed in accordance with the provisions of this code.
5. Combustible piping within concealed ceiling spaces installed in accordance with the International Mechanical Code and the International Plumbing Code.

 

[Penguin87]

Generally you can install a firestop foam or sealant product that is certified under ASTM E814 or UL 1479, such as by HILTI or equivalent manufacturer.

Ie - https://www.hilti.com/c/CLS_FIRESTOP_PROTECTION_7131/CLS_FIRESTOP_SEALANTS_SPRAY_7131

I believe you only need a metal sleeve on pipes greater than 6" diameter, at least in the IBC.

 

[klarenbeek]

Penetrating the top (floor) side of a floor-ceiling assembly IS a membrane penetration, and requires a listed penetration seal assembly if the floor-ceiling assembly is fire-resistance rated.

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.

 

[Yankee Chronicler]

Generally you can install a firestop foam or sealant product that is certified under ASTM E814 or UL 1479, such as by HILTI or equivalent manufacturer.

Ie - https://www.hilti.com/c/CLS_FIRESTOP_PROTECTION_7131/CLS_FIRESTOP_SEALANTS_SPRAY_7131

I believe you only need a metal sleeve on pipes greater than 6" diameter, at least in the IBC.

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:

714.4.2 Membrane penetrations. Membrane penetrations
shall comply with Section 714.4.1. Where walls or partitions
are required to have a fire-resistance rating, recessed fixtures
shall be installed such that the required fire resistance will not
be reduced.

714.4.1 Through penetrations. Through penetrations of fire-
resistance-rated walls shall comply with Section 714.4.1.1 or
714.4.1.2.

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