1. Membrane penetrations of maximum two-hour
fire-resistance-rated walls and partitions by steel
electrical boxes that do not exceed 16 square
inches (0.0103 m2) in area, provided the aggregate
area of the openings through the membrane does
not exceed 100 square inches (0.0645 m2) in any
100 square feet (9.29m2) of wall area. The annular
space between the wall membrane and the box
shall not exceed 1/8 inch (3.1 mm). Such boxes on
opposite sides of the wall or partition shall be separated
by one of the following:
1.1. By a horizontal distance of not less than 24
inches (610 mm);
1.2. By a horizontal distance of not less than the
depth of the wall cavity where the wall cavity
is filled with cellulose loose-fill,
rockwool or slag mineral wool insulation;
1.3. By solid fireblocking in accordance with
Section 717.2.1;
1.4. By protecting both outlet boxes with listed
putty pads; or
1.5. By other listed materials and methods.