§ 4-149. Fire and Smoke Protection Features; Section 705, Exterior Walls.

(a)

The following deletions are made to Sections 705.3 of the IBC: Section 705.3 Buildings on the Same Lot. Delete Exception 2.

(b)

Section 705.11, Parapets. Parapets shall be provided on exterior walls of buildings. However, a parapet is not required on an exterior wall where any of the following conditions (1) through (6) exist:

(1)

The wall is not required to be fire-resistance rated in accordance with Table 602 because of fire separation distance;

(2)

The building has an area of not more than one thousand (1,000) square feet on any floor;

(3)

The walls terminate at roofs of not less than two (2) hour fire-resistance-rated construction or at a roof, including the deck and supporting construction, constructed entirely of noncombustible materials;

(4)

The exterior walls are one (1) hour fire-resistance-rated that terminate at the underside of the roof sheathing, deck or slab, provided that conditions A through D below are met:

(A)

Where the roof or ceiling framing elements are parallel to the walls, such framing and elements supporting such framing shall not be of less than one (1) hour fire-resistance-rating construction for a width of four (4) feet, measured from the interior side of the wall for Groups R and U and ten (10) feet for other occupancies;

(B)

Where roof or ceiling framing elements are not parallel to the walls, the entire span of such framing and elements supporting such framing shall not be of less than one (1) hour fire-resistance-rated construction;

(C)

Openings in the roof are not located within five (5) feet of the one (1) hour fire-resistance-rated exterior wall for Groups R and U and ten (10) feet for other occupancies; and

(D)

The entire building is provided with not less than a Class B roof covering.

(5)

In occupancies of Use Groups R-2 and R-3 as applicable in Section 101.2, both provided with a Class C roof covering, the exterior wall shall be permitted to terminate at the roof sheathing or deck in Types III, IV and V construction provided that:

(A)

The roof sheathing or deck is constructed of approved noncombustible materials or of fire-retardant-treated wood for the distance of four (4) feet, or

(B)

The roof is protected with 0.625 inch Type X gypsum board directly beneath the underside of the roof sheathing or deck, supported by a minimum of nominal two (2) inch ledgers attached to the sides of the roof framing members for a minimum distance of four (4) feet. Exception: Occupancies of Use Groups R-2 and R-3 are exempt from the requirements of Subsections (5)(A) and (5)(B) of this Section when equipped with residential sprinkler systems installed in accordance with Section 903 of this Code, and the roof is covered with a minimum of a Class C roof covering.

(6)

Where the wall is permitted to have at least twenty-five (25%) percent of the exterior wall areas containing unprotected openings based on the location from a lot line as determined in accordance with Section 705.8.1 of this Code.

(CB-98-1991; CB-63-1995; CB-82-1998; CB-54-2002; CB-45-2012; CB-90-2015)