ARCH 410 Lecture Notes - Lecture 1: Ryerson University, Polyvinyl Butyral, Float Glass
3/9 Skin 3
● curtain wall does not directly mean glass
● wind pressure is much more consequential than gravity in many cases
● Langdon WIlson, former CNA company: world’s dumbest building because of simple
glass, architectural material choice was bad
● Glass
○ Characteristics
■ non-crystalline amorphous solid
■ soda-lime glass
■ non-ductile
■ not so useful for structural system; fail without too much warning
○ Types
■ float glass (molten glass to produce absolute flat and smooth glass)
■ tinted (changing surface and internal character; using minerals like salt;
can be used for heating or optical purposes)
■ coated (changing appearance)
● low-heat specificity coatings makes heat passes through glass, let
heat maintain the building instead of radiating out, suitable for
hotter climates like LA, very common)
■ frits (usually ceramic; heat applied)
● i.e. Weiss/Manfredi, Singh Center for Nanotechnology,
Philadelphia; Snohetta, Ryerson University Student Learning
Centre Toronto
■ low-iron glass (remove impurities to make it clearer; architect’s favorite;
doesn’t have the green cast)
■ laminated glass
● a sandwich produced by heat and pressure
● interlayer: PVB (polyvinyl butyral) + ionoplast (Sentryglas)
● safety glass (plastic layer) will hold the two pieces together even
though the two will break
○ this layer also reduces UV rays, provides acoustic benefits,
ballistic resistance
○ if next to a freeway, don’t use double pane!
■ IGU (insulating glass units; double pane glass)
● could be triple paned
● separate the two pieces of glass through a ½” cavity filled with air
or thermal insulation
○ overall thickness: 1” commercial; ” residential
● spacer: contains desiccants that remove intruding moisture
● all factory made; no made-on-site
○ Properties
■ annealed: common float glass
find more resources at oneclass.com
find more resources at oneclass.com
● cooled rapidly then heated then cooled slowly to relieve internal
stresses
● brittle
● workable: can cut, drill holes, polish edge, stress free
■ tempered:
● from annealed glass, heat, cool rapidly and locks in stress
● 4x bending strength
● crumple into small square pieces → safety glass
(compared to shards)
● deformation on srf because of how this was made
● not possible to cut, drill, polish after tempering
● chemical tempering possible
● roller wave: the image becomes blurry or slurred through glass;
i.e. Norman Foster glass glazing railing along elevated walkway
■ heat-strengthened:
● lock in heat on building facade, tends to crack under thermal
stress
● not safety glass
○ Systems
■ stick, panel, point fixed, _____
● stick: built in field, mullions first, low transportation cost, small
components but high labor costs, not common for large projects
(they seek an unitized system), installation of glass happens in the
field
○ i.e. Coop Himmelblau, LAUSD High School; Massimiliano
Fuksas My Zeil, Frankfurt (the hole sucking into the
interior); MVRDV+AGC Glass, Glass Farm (large panes of
glass installed; no need to pass any energy codes)
● unitized: prefabricated units = cassettes; efficient on site
assembly, good quality control
○ i.e. OMA CCTV
● point-supported:
○ mechanical connection through glass plane; monolithic or
laminated glass; spider connections: rigid or tension-based
system
○ there is no frame, only a weather seal or silicon joint
○ i.e. Sou Fujimoto, Palm Court Miami
● clamped: glass is edge support at a certain point
○ i.e. Foster, Willis-Faber-Dumas; Toyo Ito, Mediatheque
○ structural glazing: compression based
■ glass strength in compression varies and susceptible to even small
defects
■ brittle and non-plastic behavior
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Curtain wall does not directly mean glass. Wind pressure is much more consequential than gravity in many cases. Langdon wilson, former cna company: world"s dumbest building because of simple glass, architectural material choice was bad. Not so useful for structural system; fail without too much warning. Types float glass (molten glass to produce absolute flat and smooth glass) tinted (changing surface and internal character; using minerals like salt; can be used for heating or optical purposes) Centre toronto low-iron glass (remove impurities to make it clearer; architect"s favorite; doesn"t have the green cast) laminated glass. A sandwich produced by heat and pressure. Separate the two pieces of glass through a cavity filled with air or thermal insulation. Spacer: contains desiccants that remove intruding moisture. Cooled rapidly then heated then cooled slowly to relieve internal stresses. Workable: can cut, drill holes, polish edge, stress free tempered: from annealed glass, heat, cool rapidly and locks in stress.
