(a) At a distance greater than 200 feet from a Residence District boundary, the open storage of materials or products, where permitted, shall be screened from all adjoining zoning lots, including zoning lots situated across a street, by either:
(1) a strip at least four feet wide, densely planted with shrubs or trees which are at least four feet high at the time of planting and which are of a type which may be expected to form a year-round dense screen at least six feet high within three years; or
(2) a wall or barrier or uniformly painted fence of fire-resistant material, at least six feet but not more than eight feet above finished grade. Such wall, barrier, or fence may be opaque or perforated, provided that not more than 50 percent of the face is open.
(b) In addition, such screening provided pursuant to paragraphs (a)(1) or (a)(2) of this Section:
(1) shall not be located within a front yard ;
(2) shall be maintained in good condition at all times;
(3) may be interrupted by normal entrances or exits; and