Section 27-286
§ 27-286 Classification. When two or more classes of construction
occur within the same building, the entire building shall be subject to
the most restrictive occupancy and size limitations for the classes of
construction involved. However, if the occupancies within the different
classes of construction are completely separated by construction that
meets the fire-resistance rating requirements for fire divisions listed
in table 5-2 then each occupancy so separated may, for the purposes of
this code, be considered as a separate building ("building section").
Section 27-287
§ 27-287 Restrictions. In buildings of mixed construction, no
structural element shall be supported by construction having a lower
fire-resistance rating than that required for the element being
supported.