Page 92 - Between light and shade

between light and shade, TRANSPARENCy and reflection

of cornices, architraves and dripstones. On a
smaller scale, since ancient material technologies
essentially only permitted assembly by stacking
up small pieces of stone or wood, construction
common sense required each element to be set
forward of the one it rested on: this is the prin-
ciple of the “drip deflector”, which prevents
water seeping into the joint, where it would
surely damage the building.

The roof overhang remains entirely rele-
vant in contemporary architecture, but without
copying the shapes of the past. On the contrary,
reflection can be developed further: as an
overhang becomes ineffective for facades higher
than two storeys, there is a need to create addi-
tional protection using strips, continuous or
not, distributed evenly over their height (main-
tenance passageways, terraces, etc.).

The emergence of waterproof materials such
as metal sheets (copper, zinc, bronze, steel alloys,
aluminium, etc.), composite material panels
(PVC, polyester, butyl, EPDM, etc.) and large
expanses of glass 3 does not call into question the

3 In the 19th century, the first glass roofs on a metal frameworks
gave rise to the invention of “pure linseed” sealant, a mixture
of chalk and linseed oil, whose use rapidly spread to all glazed
panes, both to guarantee their water-tightness and to improve
their rigidity. The glass remains mechanically attached by
chocking with small nails for wooden frames and with a
glazing bead for metal frames (steel, aluminium, bronze,
copper).
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