The next step
in the installation procedure was to push the glass panel onto the masonry
substrate. Every horizontal seam and abutment was separated by a 1/16
inch thick adhesive cork tape recessed from the front surface by 1/8 inch.
Vertical edges were kept apart at a uniform 1/32 inch. In either case,
the joint opening was then buttered with a joint cement which was colored
to match the surrounding glass.
detailing at the edges of the veneer could prolong the life of the pigmented
structural glass. For example, to prevent possible chipping and cracking
of the glass where it met the sidewalk, a cushion of neoprene or leather
was provided and the exposed surface then caulked. The side edges of the
glass were detiled in a variety of methods or the glass simply terminated
at the desired location with the ends ground smooth. In either case, the
edge was secured to the substrate with a mastic and the joints or void
filled with joint cement or caulking compound. Where the edge of the glass
abutted another material, such as the brickwork of a neighboring storefront,
the glass was held back 1/8 inch to 1/4 inch from the adjacent material.
The gap was usually filled with pliable calk to permit expansion and to
prevent moisture migration.