(a) Structural design criteria. The building main wind force resisting system and structural components shall be designed per ASCE 7 for a 115 mph minimum peak three-second gust design speed with a load factor of 1.6, and an importance factor for occupancy Category III. Topographic and directionality factors shall be the site-specific values determined per Article 1, § 1609. Design for interior pressure based on the largest opening in any exterior facade or roof surface.
(b) Windborne debris missile impact for building enclosure elements. Exterior glazing and glazed openings, louvers, roof openings and doors shall be provided with windborne debris impact resistance or protection systems conforming to ASTM E1996-05 Level D, i.e., 9 lb. 2 x 4 @ 50 fps (34 mph).
(c) Cyclic pressure loading of impact resistive glazing or windborne impact protective systems. Resistance to the calculated maximum inward and outward pressure shall be designed to conform to ASTM E1996-05.
(d) Windows. All unprotected window assemblies and their anchoring systems shall be designed and installed to meet the wind load and missile impact criteria of this section.
(e) Window protective systems. Windows may be provided with permanent or deployable protective systems, provided the protective system is designed and installed to meet the wind load and missile impact criteria and completely covers the window assembly and anchoring system.
(f) All exterior and interior doors subject to possible wind exposure or missile impact, or both, shall have doors, frames, anchoring devices, and vision panels designed and installed to resist the wind load and missile impact criteria or such doors, frames, anchoring devices, and vision panels shall be provided with impact protective systems designed and installed to resist the wind load and missile impact criteria of this section.
(g) The building enclosure, including walls, roofs, glazed openings, louvers, and doors, shall not be perforated or penetrated by windborne debris, as determined by compliance with ASTM E1996-05 Level D.
(h) Parapets shall satisfy the wind load and missile impact criteria of the exterior envelope.
(i) Roofs.
(1) Roof openings. Roof openings (e.g., HVAC fans, ducts, skylights) shall be provided with protection for the wind load and missile impact criteria of subsections (b) and (c).
(2) High wind roof coverings. Roof coverings shall be specified and designed according to the latest ASTM standards for high wind uplift forces.
(3) Roof drainage. Roofs shall have adequate slope, drains, and overflow drains or scuppers sized to accommodate 100-year hourly rainfall rates in accordance with § 16-1.1 (181), but not less than 2 inches per hour for six continuous hours.
(1990 Code, Ch. 16, Art. 14, § 16-14.4) (Added by Ord. 12-34)