Do Fire-Rated Exterior Walls Need to Wrap Corners of Building?

[fj80]

2015 IBC, Table 602, 4-story building with ground floor retail and 3 stories of apartments above.

Rectangular building with two opposite side walls right on the property lines, and the front and rear walls have more than 30' separation. First floor is Mercantile use, so 2 hour rated side walls at property line. Levels 2-4 are Residential use, so 1 hour rated side walls at property line.

Question: Does the fire rating of the side walls need to wrap around the corners to the front and rear walls for some specified distance? My coworker has suggested they do but I don't see any such requirement in the code.

 

[RLGA]

Not required to wrap. The fire rating of those surfaces are based on the fire separation distance measured at 90-degrees from those surfaces.

 

[fatboy]

[BF] FIRE SEPARATION DISTANCE. The distance measured
from the building face to one of the following:
1. The closest interior lot line.
2. To the centerline of a street, an alley or public way.
3. To an imaginary line between two buildings on the lot.
The distance shall be measured at right angles from the
face of the wall.

 

[khsmith55]

Agree with RGLA if the building is parallel with the lot line, if not there may be other walls affected. Draw a line(s) parallel to the lot line the required separation distances to make sure.