No roof sign shall be placed in such a manner as to prevent the free passage from one part of the roof upon which such sign is erected to any other part thereof. Neither shall such sign be so placed as to interfere or block any openings in such roof.
No part of a roof sign shall project beyond the wall lines of the building whereon it is placed.
All roof signs shall be set back so that there shall be a space of at least four feet between the face of the sign and the face of any wall of the building whereon it is erected; provided, that ends of signs set diagonally may extend to, but not beyond wall lines.
All roof signs shall be constructed so that there shall be a minimum clear space of not less than six feet between the roof level and the lowest part of the sign structure, and there shall be a minimum clearance of not less than five feet between the vertical supports and braces thereof.
Structural elements of every roof sign erected shall be entirely of metal, including the uprights, supports and braces; provided, that subject to the approval of the chief building official, battens behind the metal facing, molding and decorative lattice work may be of wood construction, treated with a fire resistant compound.
Any roof sign erected upon any frame building shall be supported only upon load bearing walls or columns of the building. Any person desiring to erect a roof sign shall submit to the chief building official a diagram or sketch showing the general character of the proposed sign and placement, and a written statement from a licensed architect or engineer certifying as to the safety of the proposed sign and placement.
The maximum height of a roof sign shall be twenty feet above the roof line, the measurement shall be from the base of the roof to the top of the sign.
One roof sign shall be allowed for each street frontage of the building upon which the sign is placed. The maximum area in square feet for roof signs shall be computed by allowing four square feet of sign space for each front foot of the lot on which the building is constructed; provided, that no roof sign shall exceed 800 square feet for one side only.