The regulations set forth in this section shall apply to signs in all commercial and manufacturing districts and such signs shall require a permit.
(a) In a commercial or manufacturing district, each business shall be permitted one flat or wall on-premises sign. Projection of wall signs shall not exceed two feet measured from the face of the main building. The area of all permanent on premises signs for any single business enterprise may have an area equivalent to one and one-half square feet of sign area for each lineal foot of building width, or part of a building, occupied by such enterprise but shall not exceed a maximum area of 100 square feet;
(b) In a commercial or manufacturing district, two off-premises signs with a total area not exceeding 600 square feet may be permitted at a single location. No single off-premises sign shall exceed 1, 200 square feet, nor shall off-premises signs visible to approaching traffic have a minimum spacing of less than 200 feet. Off-premises signs shall conform to all applicable yard and height regulations for the appropriate zoning district, except that such signs intended to be viewed from an elevated highway shall be not more than twenty feet above the level of the roadway at its nearest point. Off-premises wall signs shall have all structural and supporting members concealed from view.