The following accessory uses shall be permitted
in the IP zone:
A. Storage buildings and warehouses, including garaging
of vehicles.
C. Power substations, water and sewage facilities.
D. Any use which the Board of Adjustment determines as
one customarily incident to the principal permitted use on the premises
other than a nonconforming use.
The buildings shall be of masonry construction
or its equivalent or better. No building on any plot in an Industrial
Park District shall be constructed of sheet or corrugated steel, iron
or asbestos; nor shall any building be constructed or altered of wood
frame. Should any such building be constructed of cinder or concrete
blocks, tile blocks or tile bricks, the front of said building shall
be finished with face brick, common brick painted, stone or their
equivalent. When the exterior walls, except the front wall, are constructed
of cinder or concrete block, unless such exterior walls are finished
in stucco or Gunite or their equal, the joint shall be tooled or pointed,
and such exterior walls shall be rubbed down and painted with a standard
waterproofing paint.