1. Chapter 21 Cladding with Metal & Glass

2. Metal & Glass Curtain Walls
Connected to , but isolated from, the building frame
Support only their weight & resist lateral forces
Insulated & thermally broken
Maximize comfort, minimize H/C costs & condensation
Incorporate advanced glazing & spandrel materials (luminous & thermal properties)
Gaskets & drainage to prevent water infiltration
Architectural appearance & ease of installation
Internal features, fasteners, etc. … concealed
Multiple extrusion shapes, finishes, & colors

4. Metal Frames - Extrusions
Aluminum - the metal of choice
Doesn’t corrode (beyond a thin oxidized layer)
Can accept, and hold, a variety of finishes
Economically fabricated - extruded (multiple shapes)

5. Extrusion Heated metal is forced through a die
Continuous ribbon of material
Highly precise cross-section
Multiple shapes available
Die

6. Extrusion

7. Thermal Breaks Aluminum - not a good insulator
Cold climates - inside metal cold
Interior condensation (even frost)
Hot climates - metal cooled by AC
Exterior condensation
System Needs - Thermal Break

8. Thermal Break Definition Construction (rubber or plastics)
“internal components of insulating material that isolate the aluminum on the interior side of the component (mullion) from aluminum on the exterior face”
Construction (rubber or plastics)
Thermal
Break

9. Thermal Breaks

10. Aluminum Finishes Natural oxidized finish - not attractive
Applied Coatings
Annodized coatings
Organic coatings
Multi-coat sprayed
Powder Coatings
sprayed powder - baked
Polyvinyl chloride (PVC)
Mechanical Finishes
brush, sandblast, polish, etc.

11. Annodized Coatings Oxidized coating produced in an acid bath
Additives can produce a number of colors
Most common - bronzes
Advantages:
Extremely hard coating
Very good resistance to weather & fading
Disadvantage: color consistency

12. Sampling of
Mullion Colors
Aluminum & Glass L.C.

13. Assembly
Components
Mullions
Shear Blocks
Screws
Gaskets
“Snap-ons”

14. Modes of Curtain Wall Assembly
Stick Systems
Unit System
Panel Systems
Column Cover & Spandrel System

15. Stick Systems Components Vertical Mullions Horizontal Mullions
Glass Panels
Spandrel Panels
Assembly
In the “Field”
Advantages
Minimal shipping bulk
Latitude for field adj.
“Hand” set components
Economical
Disadvantages
Built on “site”-
Quality Control

16. ‘Stick’ Systems

17. Unit Systems Components Pre-assembled Framed Unit Assembly
Factory Assembly
Field unit installation
Advantages
Minimizes on-site labor
Factory - “controlled”
Disadvantages
Larger shipping bulk
Site protection of mat’l
Heavier wgt. - cranes?

18. Panel Systems Components Homogenous units Formed from sheet metal
Assembly
Fabrication - shop
Field installed
Advantages
Minimizes on-site labor
Factory - “controlled”
Disadvantages
$ of custom molds
Larger shipping bulk
Site protection of mat’l
Heavier wgt. - cranes?

19. Column Cover & Spandrel
“emphasizes the structural module of the building”
Components
Column Covers
Spandrel panels
Glazing units
Assembly
Field installation
Disadvantages
Field Assembly
$ for custom design
(no “standard” blg. module)

20. Column Cover & Spandrel

21. Types of Glazing Outside Glazed Inside Glazed
“Glass installed (or replaced) from the outside”
Simple mullion system
Typically more economical on low-rise blgs.
Inside Glazed
“Glass installed (or replaced) from the inside”
More elaborate mullion components/system
Higher material costs
Typically more convenient & economical on tall buildings
Lower field labor costs

22. Outside glazed “stick” system
Snap Cover
Shear Block
Thermal Break
Pressure Plate

23. Stick system “externally” glazed Thermal Break Interior Gaskets
Pressure Plate

24. One Piece Extrusion
Two Piece Extrusion

25. Building Anchorage
Mullion “Splicing”

26. Inside Glazed

27. Inside Glazed Bottom Half of the Horizontal Mullion Installed after
continued
Bottom Half of the
Horizontal Mullion
Installed after
Glass Installation

28. Expansion Joints Metal and Glass
Aluminum
High coefficient of thermal expansion
Twice the coefficient of Glass
Aluminum to Glass expansion / contraction
Gaskets
Blocks (spacers) keep glass form Walking w/i opening
Aluminum mullion Expansion / Contraction
Telescoping joints in vertical mullions
Horizontal mullions cut slightly short

29. Sloped Glazing - Skylight

30. Sloped Glazing - Skylight

31. Unique Problems w/ Sloped Glazing Solution Gravity “pulling” H2O thru
the “System”
Internal Condensation
Both can cause
discomfort - occupants
damage
Solution
“Internal Drainage System

32. Sloped Glazing - Skylight

33. Cladding In Metal

34. Sheets of Copper

35. Stainless Steel

36. SS Jointing

37. Painted Metal Panels

38. Metal Panels

39. Aluminum Panels

40. Aluminum Panel Column Covers

41. Aluminum Panel Column Covers

42. Aluminum Panels

43. Experience Music Project
‘Rock n Roll Museum’
Seattle
(6 photos)
Stainless Steel,
Copper,
and Coated
Metal Panels

49. Curtain Wall Design
Complex & Specialized Process (often a proprietary system adopted that meets design criteria)
Design ‘specialists’ consulted
Concept drawings prepared by A&E
Detailed design documents prepared by manufacturer – followed by shop dwgs.
A/E reviews to ensure design compliance
Full-scale testing
Manufacturer and then erection

50. Sustainability in Aluminum Cladding
Raw material plentiful, but refining requires considerable energy (embodied energy 6x steel)
Large quantities of water required for smelting & waste water contains pollutants
Aluminum recycled at a very high rate
Extrusions easy to produce and light weight
Powder coating release no solvents into the atmosphere
Low maintenance, but highly conductive (thermal breaks required)