283757893275

Cladding and Curtain Wall Construction 469
Insulated plastic insert to
form interlocking joint
Neoprene gasket
Recessed joint
Interlocking
joint
Figure 7.47 Interlocking panel joint with neoprene gasket.
in slender steel sections as continuous horizontal features between undercill panels and as
large metal-framed windows. During the same period, rolled plate glass was extensively
used in rooflights to factories, the glass being supported by glazing bars fixed down the
slope of roofs. Many of the sections of glazing bar that were developed for use in rooflights
were covered by patents so that roof glazing came to be known as ‘patent glazing’ or ‘patent
roof glazing’.
Curtain walling
The early uses of glass as a wall facing and cladding material were developed from metal
window glazing techniques or by the adaptation of patent roof glazing to vertical surfaces,
so that the origins of what came to be known as ‘curtain walling’ were metal windows and
patent roof glazing. The early window wall systems, based on steel window construction,
lost favour principally because of the rapid and progressive rusting of the unprotected steel
sections that in a few years made this system unserviceable.