Building design rules for wind, rain, and flying debris

(a) Structural design criteria. The building main wind force resisting system and structural components must be designed per ASCE 7 for a 145 mph minimum peak 3-second gust ultimate design wind speed. Topographic and directionality factors must be the site-specific values determined per State Building Code Appendix W. Design for interior pressure must be 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 must be provided with windborne debris impact resistance or protection systems conforming to ASTM E1996-14 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 must be designed to conform to ASTM E1996-14. (d) Windows. All unprotected window assemblies and their anchoring systems must 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 that 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 must 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 must be provided with impact protective systems designed and installed to resist the wind load and missile impact criteria of this section. (g) Exterior envelope. The building enclosure, including walls, roofs, glazed openings, louvers, and doors, must not be perforated or penetrated by windborne debris, as determined by compliance with ASTM E1996-14 Level D. (h) Parapets. Parapets must 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) must be provided with protection for the wind load and missile impact criteria of §§ 16-14.5 (b) and 16-14.5 (c). (2) High wind roof coverings. Roof coverings must be specified and designed according to the latest ASTM Standards for high wind uplift forces or International Building Code Section 1507, whichever is greater. (3) Roof drainage. Roofs must have adequate slope, drains, and overflow drains or scuppers sized to accommodate 100-year hourly rainfall rates in accordance with International Building Code Section 1611.1 and Figure 1611.1 but not less than 2 inches per hour for 6 continuous hours.