Rated Wall supporting a rated mezzanine - windows?

[buckie06]

Hello all,
We have a metal building with a mezzanine. Offices are on the rated mezzanine, separate occupancy in the rest of the building. and the walls supporting the mezzanine are rated. The rated west exterior wall that is supporting the mezzanine has windows on the ground floor. The building inspector is questioning if the window returns need to be rated as well (3 layer fire barrier). Do the windows on the ground floor need to be rated in the wall that is supporting the mezzanine?

thanks

 

[buckie06]

Building type is VB.

Another way to ask the question: can rated walls that support a rated assembly have non-rated penetrations? The wall is only supporting the assembly above, it's not providing fire protection between rooms on the ground floor......??

thanks for any help you can provide.

 

[LR419]

The structure framing the opening would need to be protected, 704.10 in 2021 IBC (assuming the project is in CO). The opening protective for the window itself would depend on the fire separation distance, 705.8.

 

[buckie06]

Interesting. I found this quote from a code consultant: https://coderedconsultants.com/insights/mezzanine-structure-fire-rating/

• The fire rating of mezzanine floors is not required from a vertical opening perspective, only a structural stability perspective. As such, penetrations of the mezzanine floor are not required to be protected with approved firestop assemblies provided the omission of such assemblies does not compromise the structural integrity of the floor in a fire event.

Would that also apply to my rated vertical wall that is supporting the mezzanine?

 

[buckie06]

any other thoughts?

 

[steveray]

Why is the mezzanine rated?

 

[buckie06]

Why is the mezzanine rated?

The mezzanine is office use whereas the rest of the building is storage

 

[steveray]

The mezzanine is office use whereas the rest of the building is storage

And it does not work as mixed use non-separated?

 

[buckie06]

And it does not work as mixed use non-separated?

Due to a lack of fire flow at the site, the fire department has requested the suites be separated by a 2hr fire wall. and that Office use be separate from Storage use by 2hr fire barriers

 

[steveray]

Due to a lack of fire flow at the site, the fire department has requested the suites be separated by a 2hr fire wall. and that Office use be separate from Storage use by 2hr fire barriers

Interesting....You should probably ask them how to build it then as they seem to be designing it with no specific code sections....

 

[Mr. Inspector]

Cannot exit through a storage room.

 

[Paul Sweet]

1016.2.2 allows egress through a storage room if the offices are accessory to the storage and there is a well marked path.