Regarding the separation for R-2 and M, which code would I follow to determine the horizontal separation rating for a Mercantile on the ground floor and R-2 units above?
IBC 420 states that walls separating differing occupancies associated with R shall be in the same manner as the walls between the units themselves and references section 711. Chp. 7 states that the horizontal assemblies shall be 1 hr non-sprinkler and 1/2 sprinkler.
IBC table 508.4 references section 420 but also provides a separation rating higher than what is prescribed in section 711. (I know confusing)
Which takes precedence? The stricter requirement or the footnote?