(a) During the construction of exterior masonry walls of any building or other structure, except chimneys, from a floor or scaffold inside the building or other structure and such floor or scaffold is more than 35 feet above the adjoining ground or equivalent surface, there shall be provided along the exterior face of such wall a catch platform, installed in compliance with this Part (rule) with the following exceptions:

1. (1) In lieu of the required barricade or fence on all open sides of the catch platform, such sides shall be provided with planks whose minimum cross-sectional dimensions shall be two inches by nine inches or material of equivalent strength having one dimension at least nine inches. Such planks or material of equivalent strength shall be so placed that the greater dimensions are vertical.
2. (2) A two-inch space may be left between the inner edge of the catch platform and the face of the wall of the building or other structure.