2 hour fire barrier wall - PEMB

[BobbiM]

I'm needing a UL rating for a 2 hour metal stud wall that will be built in a PEMB, perpendicular to the roof purlins. I have one building that has an S-1 occupancy on one end with a B occupancy in the remaining building. The 2018 IBC is requiring a 2 hour fire barrier wall, separating the 2 occupancies.

I can find 1 hour details, such as HW-D-0489 but none that show 2 hour.

What do you suggest? Maybe there is a "work around" I'm unaware of. The S-1 area is 1,230 sf, the B occupancy is 2,460 sf. with a total building SF of 3,690.

Thanks for your help!!

 

[steveray]

U419 wall....But a building that small should not need a separation.....And Welcome to THE Forum!

 

[BobbiM]

U419 wall....But a building that small should not need a separation.....And Welcome to THE Forum!

Non-separated occupancies.....Duh!! I forgot about that one! Thanks for the quick reply.

 

[RLGA]

Even if you needed separated occupancies, Table 508.4 does not require separation between Group B and S-1 occupancies.

 

[BobbiM]

Even if you needed separated occupancies, Table 508.4 does not require separation between Group B and S-1 occupancies.

My bad....It's a B and S-2!

 

[Penguin87]

I'm needing a UL rating for a 2 hour metal stud wall that will be built in a PEMB, perpendicular to the roof purlins. I have one building that has an S-1 occupancy on one end with a B occupancy in the remaining building. The 2018 IBC is requiring a 2 hour fire barrier wall, separating the 2 occupancies.

I can find 1 hour details, such as HW-D-0489 but none that show 2 hour.

What do you suggest? Maybe there is a "work around" I'm unaware of. The S-1 area is 1,230 sf, the B occupancy is 2,460 sf. with a total building SF of 3,690.

Thanks for your help!!

UL assemblies are awesome!

There are so many. Here are some great resources to get you started:

The Purple Book II | Commercial Construction Details

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www.nationalgypsum.com

UL Wall Assemblies, Fire Rated Wall Designs | USG

USG’s range of resources on UL wall assemblies can help with the planning and estimation of your next project.

www.usg.com

AG Design Library - American Gypsum

The AG Design Library is a robust tool to help you quickly find fire and sound rated assembly information.

www.americangypsum.com

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iq.ulprospector.com

https://iq.ulprospector.com/en/_?tt=1002

You should definitely use the UL prospector tool. Its free to register and it has EVERYTHING.
And, the purple book is like a details bible. Highly recommended.

 

[Tim Mailloux]

U419 wall....But a building that small should not need a separation.....And Welcome to THE Forum!

good old U419 covers so many situations

 

[Yankee Chronicler]

The U419 wall is the easy part. The issue will be maintaining the rating where the wall has to be coped around the roof purline ...

 

[Penguin87]

I would look at something like a deflection clip attached to the purlins, or a slotted deflection track hitting blocking attached to the purlins.
Then just notch the gyp board around the purlins.

 

[Yankee Chronicler]

I would look at something like a deflection clip attached to the purlins, or a slotted deflection track hitting blocking attached to the purlins.
Then just notch the gyp board around the purlins.

And then ... ?

2021 IBC:

707.5 Continuity. Fire barriers shall extend from the top of
the foundation or floor/ceiling assembly below to the underside
of the floor or roof sheathing, slab or deck above and shall
be securely attached thereto. Such fire barriers shall be continuous
through concealed space, such as the space above a
suspended ceiling. Joints and voids at intersections shall
comply with Sections 707.8 and 707.9

707.9 Voids at intersections. The voids created at the intersection
of a fire barrier and a nonfire-resistance-rated roof
assembly or a nonfire-resistance-rated exterior wall assembly
shall be filled. An approved material or system shall be used to
fill the void, and shall be securely installed in or on the intersection
for its entire length so as not to dislodge, loosen or
otherwise impair its ability to accommodate expected building
movements and to retard the passage of fire and hot gases.

PEMB roof purlins are usually Z shapes. Where each purlin runs through the fire barrier is a "penetration" under the code. Those need to be sealed with a listed joint seal assembly.

 

[Inspector Gadget]

You should definitely use the UL prospector tool. Its free to register and it has EVERYTHING.
And, the purple book is like a details bible. Highly recommended.

^^^This.

 

[Penguin87]

And then ... ?

2021 IBC:





PEMB roof purlins are usually Z shapes. Where each purlin runs through the fire barrier is a "penetration" under the code. Those need to be sealed with a listed joint seal assembly.

Yeah, the architect would need to figure that out. I don't work for free, lol

PEMBs are a little tricky due to their deflection under wind loads. In the past I've done a 2-hour fire rated hard lid over a room that was required to be fire rated.

 

[TheCommish]

I had a steel frame building with roll bar trusses that they built a rated room in and they had to account for the deflection of the roof frame. They put a track Channel attached to the roof deck framed a short wall down and had it overlap by 6 inches or more with the double layer of sheetrock the lower wall and they provided me with an assembly as I recall for this detail