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Caring for Today’s Architectural Glass
Over the past 40 years, the
flat glass industry has answered the calls from
building architects for safer, more
aesthetically pleasing, and more energy
efficient glass products to replace the single
pane, clear, annealed (non-heat treated) glass
that has been used for centuries.
The industry’s response has
been high-performance glass products
incorporating innovations such as heat-treating,
coatings, laminating, and multi-pane insulating
units. These high-performance glass products
dominate the vision and non-vision (spandrel)
glazing in today’s building construction.
Many of these unique glass
products are heat-treated during the fabrication
process. Heat-treating glass involves moving
cut-to-size glass pieces horizontally on ceramic
rollers through an oven that heats the glass
close to its softening point and then quenching
the glass with high volumes of air to create the
desired surface compression for increased
strength, impact resistance, and other
attributes of enhanced performance.
It is a scientific fact that
heat-treating glass does not change the surface
hardness (i.e., scratch resistance) of the
glass. Annealed glass and heat-treated glass
have the same glass hardness.
Heat-treating does, however,
change the glass surfaces in other ways.
Heat-treated glass may have slight surface
markings, roller waves, or overall bow resulting
from the soft glass riding on the ceramic
rollers. The glass also may have microscopic
particles adhering to one or both surfaces.
These particles can come from any one of a
variety of sources in the heat-treating process.
The glass heat-treating
industry cannot guarantee or warrant that
surface particles or any of the other conditions
mentioned above will be completely eliminated
from random occurrence on finished tempered or
heat-strengthened glass products, even when
using properly maintained equipment, and
observing good housekeeping and fabrication
processes.
Like many specially
engineered products, high-performance glass
products require special care and handling. The
producers of these products, as well as the
Glass Association of North America (GANA), have
generated documents to assist building
construction companies, post-construction
cleaning companies, and building owners and
managers to properly care for these products.
These documents can be obtained free of charge
from the original manufacturer of the glass
product or from the GANA organization website (www.glasswebsite.com).
The GANA documents Proper Procedures for
Cleaning Architectural Glass Products and
Heat-Treated Glass Surfaces Are Different,
emphasize the need to avoid the use of scrapers
in the glass cleaning process because their use
carries the high risk of scratching the glass
surface when the scraper drags surface particles
left on the glass, whether by the heat-treating
process or as construction grit/dirt, across its
surface.
Copyright, GANA |
