§ 118-241. Design.

(a)

Generally. All signs and sign structures shall be designed and constructed to resist wind forces as specified in this division. All bracing systems shall be designed and constructed to transfer lateral forces to the foundations. For signs on buildings, the dead and lateral loads shall be transmitted through the structural frame of the building to the ground in such manner as not to overstress any of the elements thereof. The overturning movement produced from lateral forces shall in no case exceed two-thirds of the dead-load resisting moment for all signs. Uplift due to overturning shall be adequately resisted by proper anchorage to the ground or to the structural frame of the building for all signs. The weight of earth superimposed over footings may be used in determining the dead-load resisting moment. Such earth shall be carefully placed and thoroughly compacted. The allowable stresses in wire ropes and steel guy rods and their fastenings shall not exceed one-fourth of their rated tensile strength.

(b)

Wind loads. All signs and sign structures shall be designed to resist wind loads as follows:

WIND LOAD PRESSURES FOR ALL SIGNS

Height Above   Ground   (In Feet)*	Pressure (In Pounds per Square Foot)
0—30	20
31—50	25
51—99	35
100—199	45
200—299	50
300—399	55
400—500	60
501—800	70
Over 800	77

 

*Measured above the average level of the ground adjacent to the structure.

(c)

Vertical design loads. Vertical design loads, except roof live loads, shall be assumed to be acting simultaneously with the wind loads.

(d)

Working stresses. All signs shall be designed to conform with the requirements of the building code regarding allowable working stresses. The working strength of chains, cables, guys or steel rods shall not exceed one-fifth of the ultimate strength of such chains, cables, guys or steel rods.

(Code 1967, § 25½-7(A); Ord. No. 3593, § 1, 4-14-83; Ord. No. 4123, § 3, 4-11-85; Ord. No. 6047, §§ 1, 2, 10-22-91)