Sign structures shall be designed and constructed to resist wind and seismic forces as specified in the Uniform Building Code. 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 moment produced from lateral forces shall in no case exceed two-thirds of the dead-load resisting moment. Uplift due to overturning shall be adequately resisted by proper anchorage to the ground or to the structural frame of the building. 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. Wind and seismic loads need not be combined in the design of signs and sign structures; only that loading producing the larger stresses need be used. Vertical design loads, except roof live loads, shall be assumed to be acting simultaneously with the wind or seismic loads. (Ord. 1770 § 1, 1977; Ord. 1670 § 1, 1976).