3.6.3 Ornaments. An ornament or decoration on a freestanding, unbraced air terminal shall not present, in any plane, awind-resistance area in excess of 20 in.2 (0.01 m2). Thisrequirement shall permit the use of an ornamental ball 5 in.(127 mm) in diameter.3.7 Zones of Protection. To determine the zone of protection, the geometry of the structure shall be considered.3.7.1 Roof Types. The zone of protection for the followingroof types shall include the roof and appurtenances whereprotected in accordance with Section 3.8:(1) Flat or gently sloping roofs(2) Dormers(3) Domed roofs(4) Roofs with ridges, wells, chimneys, or vents3.7.2 Multiple-Level Roofs. For structures with multiple-levelroofs no more than 50 ft (15 m) in height, the zone of protection shall include areas as identified in 3.7.2.1 and 3.7.2.2. Thezone of protection shall form a cone whose apex is located atthe highest point of the strike termination device, with wallsforming approximately a 45-degree or 63-degree angle fromthe vertical.3.7.2.1 Structures that do not exceed 25 ft (7.6 m) aboveearth shall be considered to protect lower portions of a structure located in a one-to-two zone of protection as shown in Figures 3.7.2.1(a) and 3.7.2.1(b).
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