Parapet Exceptions

[manifold]

IBC 2015. Type V-B. Sprinklered.

First floor @ 2,400 SF and Second Floor @ 900 SF.

For a new building, the east and west walls are required to be rated 1-hour based on separation distance from the lot lines. Section 705.11 requires parapets at these rated walls but Exception 2 states that a parapet is not required if "the building has an area of not more than 1,000 square feet on any floor." Since the second floor is less than 1,000 SF, does that remove the requirement for the parapet just on the second floor portion or from the entire building?

The way the exception reads, it seems to remove the parapet requirement from the entire building. However, it is counter intuitive that a single story 2,400 SF building would require parapets but adding a small second floor would remove the requirement throughout. Please let me know your thoughts.

Worth noting: the design for the single story portion has a gable roof that slopes down to the east and west rated walls so a parapet will not work here. My goal is to not have to use Exception 4.2 & 4.3 since we have exposed glulams and skylights at the gable.

 

[mtlogcabin]

Sprinkled will get you 25% over 5 ft FSD

6. Where the wall is permitted to have at least 25 percent of the exterior wall areas containing unprotected openings based on fire separation distance as determined in accordance with Section 705.8.

 

[manifold]

Sprinkled will get you 25% over 5 ft FSD

6. Where the wall is permitted to have at least 25 percent of the exterior wall areas containing unprotected openings based on fire separation distance as determined in accordance with Section 705.8.

This is applicable on one side, but the opposite side has less than 3' separation so no openings are permitted. Still hoping Exception 2 will work.

 

[RLGA]

Talk about poorly worded sentences. Neither the Commentary nor the Handbook provide any insight into how this is to be interpreted--which means the authors probably did not know how to interpret it either. I checked ICC's official interpretations and there are none for this section. My guess is that the intent was exclude buildings that have stories that do not exceed 1000 sq. ft. in floor area. However, you can take your interpretation and see if the building department shares that interpretation. If they do, you're golden--if not, better to find out now than later.

 

[Francis Vineyard]

Below are commentaries from the 1993 BOCA, it is the same in the 1990 through 1996. Note the same exception is also found in the 1975 BOCA but not in the 1970.
The "any floor" is in the commentary for the IBC 2000.