All private radio towers must be constructed from one of the following materials: Aluminum, galvanized steel, or equally weather resistant steel. All ground mounted private radio towers exceeding 35 feet in height shall be mounted in concrete, or erected in such a manner so as to be able to withstand a minimum wind velocity of 80 m.p.h. (impact pressure of 25 pounds per square foot). A private radio tower may be bracketed to the principal structure, so long as the requirements of this subsection are satisfied.