Type 5-A const, floor-ceiling assembly rating @exterior wall

[Greg S]

IBC 2012
Occupancy Type: R-2
Construction Type: 5A

On this building the exterior walls are 1-hour rated, for exposure from the interior side only (para 705.5). My question is, does the fire rated floor-ceiling assembly qualify as also protecting the section of exterior wall at the floor-ceiling assembly? I can not find any clarity on this in the code book.

If not, does anyone have suggestions on how to treat the exterior wall at the floor-ceiling assembly per the design in this detail? I am not able to find any UL listings or details from manufacturers, trade associations, or google for for this condition.

 

[steveray]

Generally....Yes....Inspector or designer?

 

[mtlogcabin]

Yes and as for the exception in 711.2.4.3 I have never seen a listed 1/2 hour assembly

420.3 Horizontal separation.
Floor assemblies separating dwelling units in the same buildings, floor assemblies separating sleeping units in the same building and floor assemblies separating dwelling or sleeping units from other occupancies contiguous to them in the same building shall be constructed as horizontal assemblies in accordance with Section 711.

711.2.4.3 Dwelling units and sleeping units.
Horizontal assemblies serving as dwelling or sleeping unit separations in accordance with Section 420.3 shall be not less than 1-hour fire-resistance-rated construction.

Exception: Horizontal assemblies separating dwelling units and sleeping units shall be not less than 1/2-hour fire-resistance-rated construction in a building of Types IIB, IIIB and VB construction, where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.

 

[Greg S]

Generally....Yes....Inspector or designer?

Designer.

 

[steveray]

The structure is protected from the interior space with 1hr.....If the fire starts in the cavity it is not really addressed just like if it starts in the wall cavity....Sprinklering or fully insulating the floor cavity?

 

[Greg S]

The structure is protected from the interior space with 1hr.....If the fire starts in the cavity it is not really addressed just like if it starts in the wall cavity....Sprinklering or fully insulating the floor cavity?

The building is fully sprinkled (NFPA 13-R), no insulation except at the exterior wall (unfaced batt)