21 Cladding With Metal and Glass
Aluminum Extrusions
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Aluminum Extrusions
Alumnium in Curtain
Walls
• Aluminum is most common in
metal curtain wall because it:
–
–
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Protects against corrosion
Accepts and holds a variety of
attractive surface finishes
Can be fabricated into elaborate
shapes by extrusion
Is light and strong
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Aluminum Extrusions
Extrusion Production
• The principle of extrusion is
easily visualized:
–
–
It is like squeezing
toothpaste from a tube
The tube extrudes a
column of toothpaste in
the shape of the orifice
which is cylindrical
• Very intricate aluminum
sections can be extruded for
variety of purposes including
curtain wall components,
door frames, window
frames, entrances,
storefronts, handrails,
grillwork, and structural
shapes
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Aluminum Extrusions
Extrusion Production
1.
2.
3.
4.
Hundreds of extrusion
dies for many components
of curtain walls are
organized in racks
A heated billet of
aluminum is inserted into
the cylinder of the
extrusion press
An extrusion emerges
from the die
Long extrusions cool on
rollers, ready for
straightening and cutting
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Copyright © 2009 John Wiley & Sons. All rights reserved.
1
2
3
4
Aluminum Extrusions
Connections of Extruded
Shapes
1.
2.
Screw ports are extruded
1
cylindrical features that
allow a screw to be driven
in parallel to the long axis
of the extrusion
Self-tapping screws are
driven through screw ports
to fasten an extruded
aluminum shear block to
a vertical mullion
2
2
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Aluminum Extrusions
Connections of Extruded
Shapes
1.
2.
Screw slots allow screws to
be driven perpendicular to
the long axis of an
extrusion
Snap-on and snap together
features are commonly
used in extruded
aluminum curtain wall
components
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
1
2
Aluminum Extrusions
Thermal Breaks and
Finishes
• Thermal breaks
–
–
They are internal components of
insulating material that thermally isolate
the aluminum on the interior side from
the exterior side
They dramatically reduce heat flow
• Creating thermal breaks
–
–
Cast and debridged thermal break
Inserting Rubber, plastic gaskets or
plastic strips
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Aluminum Extrusions
Thermal Breaks and
Finishes
• This aluminum glazing
extrusion relies on an
extruded rubber gasket
(1) to act as a conductive
separation between the
pressure cap and the
main body of the
extrusion
• Such thermally improved
glazing systems are less
expensive than fully
thermally broken systems,
but also allow greater heat
loss
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
1
Aluminum Extrusions
Thermal Breaks and
Finishes
• Surface finishes
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Aluminum does not corrode but forms a
tenacious oxide film
Anodizing is a process that produces an integral
oxide coating on the aluminum. It can be done
in different colors
Organic coatings can also be used such as
fluoropolymer coatings, polyvinyl fluoride
(PVF) and are available in broad spectrum of
colors are most expensive but have high service
life
Powder coatings are manufactured with
thermosetting powders applied electrostatically.
Baked enamel finish consists of spray applied
acrylic or polyester polymers and have high
gloss
A wide range of surface effects are also possible
by mechanical and chemical means
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Aluminum and Glass Framing Systems
Thermal Breaks and
Finishes
• A clear-anodized
storefront
system
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
21 Cladding With Metal and Glass
Aluminum and Glass
Framing Systems
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Aluminum and Glass Framing Systems
3
Framing Systems
1.
Entrances
–
2.
Storefronts
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3.
These are systems of aluminum framed
doors, hardware, aluminum framing and
glass typically used in commercial
buildings
These are based on simplified, lighter
framing elements that are less expensive
and quicker to assemble than curtain wall
Rather then being hung it is installed
between floor slabs or wall openings
They are lighter and mostly used on
single storey
Curtain wall
–
They are more high performance and
can be used on any number of stories
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
2
1
21 Cladding With Metal and Glass
Modes of Assembly
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Stick System
• Principal components are:
–
–
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Metal mullions
Rectangular panels of glass
Rectangular panels of
spandrel
• All materials are assembled
on the building
• Low shipping bulk and high
degree of ability to adjust to
unforeseen conditions
• Assembly on site more labor
intensive and impacted by
site conditions
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Unit System
• Units with glass spandrel
and mullion are shipped to
site
• Units need more space for
shipping and more
protection from damage
then stick systems
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Unit and Mullion System
• Mullion and units are
shipped separately
• Hybrid between unit and
stick systems
• Seldom used in today’s
construction
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Panel System
• Made up of homogenous
units that are formed from
metal sheet
• Advantages and
disadvantages are similar to
unit system but its
production involves higher
tooling costs of a custom
made die or mold
• It is advantageous for
buildings that requires large
numbers of similar pieces
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Column-Cover-andSpandrel-System
• Emphasizes the structural
module of the building
rather than creating its own
grid on the facade
• A custom design must be
created for each project
• Special care required in
detailing spandrel panel
support to ensure that
panels do not deflect when
loads are applied to spandrel
beams of the building frame
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Outside Glazed Curtain
Wall System
Kawneer 1600 System – Outside Glazing
In an outside glazed system
the glass must be installed or
replaced by workers standing
on scaffolding. Outside
glazing systems utilize
relatively simple set of
shapes and are less
expensive
1.
Vertical mullions
2.
Horizontal mullions
3.
Shear block
4.
Glazing gaskets
5.
Pressure plates
6.
Snap on cover
7.
Molded rubber plug
1
3
7
5
2
6
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
4
Modes of Assembly
Outside Glazed Curtain
Wall System
Manufacturer’s details for
Kawneer 1600 – outside
glazed system. The details
are keyed to location shown
on top left
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Outside Glazed Curtain
Wall System
1
2
Detail of a vertical mullion
1.
Basic extrusion is a rectangular shape
that provides a neat appearance on the
inside
2.
Broken lines indicate a smaller profile
availability
3.
The extruded plastic thermal break
attaches to the mullion with a projecting
pine tree spline
4.
Glazing gaskets attach to aluminum
pieces with projecting splines
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
4
4
3
4
4
Modes of Assembly
Outside Glazed Curtain
Wall System
2
1
Detail of horizontal mullion
– closed extrusion top and
open-back extrusion bottom
1.
Rubber setting blocks are shown beneath the
glass
2.
Aluminum extrusion added for spandrel glass
3.
Weep holes are not shown but drilled
horizontally through the top part of pressure plate 3
4.
Weep holes are also drilled vertically through the
bottom part of the snap on cover
1
4
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Inside Glazed Curtain
Wall System
An example of a building
with outside glazed curtain
wall system
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Inside Glazed Curtain
Wall System
5
1
In an inside glazed system
workers stand inside the
building to install the glass. It
is more convenient and
economical for tall buildings
but requires more elaborate
extrusions
1.
Vertical mullions
2.
Horizontal mullions
3.
Shear block
4.
Glazing gaskets
5.
Pressure plates
6.
Snap on cover
7.
Bottom half extrusion
3
4
6
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
2
7
Modes of Assembly
Inside Glazed Curtain
Wall System
Manufacturer’s details for
Kawneer 1600 – inside
glazed system. The details
are keyed to location shown
on top left
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Inside Glazed Curtain
Wall System
1
2
Detail of a vertical mullion
1.
Basic extrusion is a rectangular shape
that provides a neat appearance on the
inside
2.
Broken lines indicate a smaller profile
availability
3.
Thermal break is an H shaped extrusion
of rigid plastic that is crimped securely
into grooves
4.
Removable glazing gaskets
5.
Glazing pockets of different depths to
allow for glazing from the inside
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
4
5
4
3
Modes of Assembly
Inside Glazed Curtain
Wall System
Detail of horizontal mullion
1.
Bottom half of mullion is off until glass is
installed
2.
Interior glazing gaskets are installed after
the bottom part of the mullion. They are
called glazing wedges because of their
blunt wedge shape
3.
3
2
Exterior gaskets have a different shape
which are installed before the glass is
installed
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
1
Modes of Assembly
Inside Glazed Curtain
Wall System
2
4
Installing glass from
inside
1.
1
Setting blocks and
exterior side gaskets are
installed
4
2
2.
Glass unit is pushed
obliquely into the deep
glazing pocket squared
away and backed into
the shallow pocket
3.
Bottom half of mullion
is installed (see previous
slide #1)
4.
Inside gaskets are
installed
1
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Modes of Assembly
Inside Glazed Curtain
Wall System
An example of a building
with inside glazed curtain
wall system
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
2
21 Cladding
With Metal and Glass
3
1
The Rainscreen Principle in
Metal-and-Glass Cladding
1
4
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Rain Screen Principle in Metal-and-Glass Cladding
Rain Screen Principle
•
•
•
During a wind-driven rain gravity and capillary
action would be likely to draw some water
past the outer gasket
If water has leaked in along the vertical edge it
will fall by gravity to the bottom where it
drains out
If water accumulates in the horizontal mullion
it is prevented from running out at the ends
by plugs shown earlier
1.
2.
3.
4.
2
3
1
1
Its only recourse is to drain through weep
holes in the pressure plate and the snap-on
cover
External gasket serves only as a deterrent seal,
essentially a rainscreen
Internal gasket serves as an air barrier
Hollow spaces are pressure equalization
chamber
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
4
Rain Screen Principle in Metal-and-Glass Cladding
Rain Screen Principle
•
•
A sheet metal, rain screen cladding system
Behind the metal skin is metal framing for supporting
the panels, a drainage space, and a waterproof
membrane
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
21 Cladding With Metal and Glass
Expansion Joints in Metaland-Glass Walls
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Expansion Joints in Metal-and-Glass Walls
Attachment and Joints in
Mullion
1.
•
•
Vertical mullions are
attached to the edges of the
building’s floor with angle
anchor. Oval slots (4) allow
for adjustments to
accommodate construction
tolerances
Sections of vertical mullions
are spliced with aluminum
internal spline shown with
dotted lines
The spline is screwed to the
lower section of mullion with
upper section free to slide to
accommodate vertical
movement
1
4
3
2
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
21 Cladding With Metal and Glass
Sloped Glazing
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
Sloped Glazing
Sloped Glazing
Kawneer 1600 S.G. Framed With Aluminum
Extrusions Incorporating Internal Gutters
• Water leakage is a big issue
and therefore there is an
internal drainage system
• Structural issues need to be
considered and laminated or
plastic glass is often required
• Moisture condensation can
also be contained by the
gutter
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.
21 Cladding With Metal and Glass
MasterFormat Sections
For Cladding With Metal
and Glass
CSI/CSC MASTERFORMAT SECTIONS FOR CLADDING WITH METAL AND GLASS
08 40 00
ENTRANCES, STOREFRONTS, AND CURTAIN WALL
08 41 00
Entrances and Storefronts
Aluminum-Framed Entrances and Storefronts
08 44 00
Curtain Wall and Glazed Assemblies
Glazed Aluminum Curtain Walls
Sloped Glazing Assemblies
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 John Wiley & Sons. All rights reserved.