CMgt3350 Building Structures

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CMgt3350 Building Structures

• Chapter 14 - Curtain Walls

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Objectives

• Explain the history of the curtain wall.
• Match terms related to curtain walls.
• Locate Curtain Walls in the CSI.
• Discuss the advantages of curtain walls versus
  standard construction.
• List and explain types of curtain wall assemblies.

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History of the Curtain Wall Andres and Smith
versus Allen.

• Andres and Smith, the authors of the text, state
  that the curtain wall, which was merely the outer
  wythe in a cavity wall assembly, was developed to
  protect the traditional concrete structure from
  rain penetration (page 452).
• A non-load-bearing exterior wall

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History of the Curtain Wall Andres and Smith
versus Allen.

• The first steel-framed skyscraper, the Home
  Insurance Building in Chicago (1883), introduced
  the concept of the curtain wall, an exterior
  cladding (made in this case of masonry) supported
  at each story by the steel frame, rather than
  bearing its own load to the foundations (Allen,
  p. 648).
• Allens glossary defines curtain wall as An
  exterior building wall that is supported entirely
  by the frame of the building, rather than being
  self-supporting or load-bearing (p. 780).

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Curtain Wall
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Terms (Allen, pages 775-798).

• Cavity Wall- A masonry wall that includes a
  continuous airspace between its outermost wythe
  and the remainder of the wall.
• Wythe- A vertical layer of masonry one masonry
  unit thick.
• Weep holes- Small openings whose purpose is to
  permit drainage of water that accumulates inside
  a building component.

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Concrete Block
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Typical Brick Walls
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Brick Terminology
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Terms (Allen, pages 775-798).

• Spandrel- The wall area between the head of a
  window on one story and the sill of the window on
  the floor above.
• Spandrel Beam- A beam that runs along the outside
  edge of a floor or roof.
• Mullion- A vertical or horizontal bar between
  adjacent window or door units.

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Curtain Wall
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Curtain Wall
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Locate Curtain Walls in the CSI

• 08900 GLAZED CURTAIN WALLS
• 08910 Glazed Steel Curtain Walls
• 08920 Glazed Aluminum Curtain Walls
• 08930 Glazed Stainless Steel Curtain Walls
• 08940 Glazed Bronze Curtain Walls
• 08970 Structural Glass Curtain Walls

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Advantages of Using Curtain Walls

• 1. Less exterior wall thicknessmore interior
  floor space
• 2. Less weightsmaller foundations less money
• 3. PrefabricationIncreased insulation and
  sealing qualities decreasing lawsuits
• 4. Prefabricationless timeless money
• 5. Many materials to choose frommore
  aesthetically pleasing than traditional concrete
  surfaces.

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Curtain Wall Materials/Assemblies

• Unit Masonry between columns and beams for
  lateral support or independent of columns and
  beams (using looped rods as anchors).

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Unit Masonry

• Build units into openings formed by the existing
  columns and beams

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Unit Masonry

• Erect a wall independent of any vertical support

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Curtain Wall Materials/Assemblies

• Stone Panels- precast and attached to steel or
  concrete structure

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Curtain Wall Materials/Assemblies

• Precast Concrete- Either cast in a factory or
  cast on the ground onsite and then lifted into
  place (aka tilt-up).

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Precast Concrete

• Panel can be cast, cured, and finished in a plant
  and then erected over a structural steel frame

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Precast Concrete

• Precast panels are made with protruding rebar
  dowels and set in place and then the columns are
  formed and poured.

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Curtain Wall Materials/Assemblies

• Lightweight Sandwich- interior metal liner with
  insul. panel, air gap, and ext. metal panel.

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Lightweight Curtain Walls

• Consist of an interior liner, insulating layer,
  and exterior finish
• Preassembled and ready for installation
• Made on site by installing the components
  individually
• Exterior finishes can be steel coated with
  enamel, aluminum, copper, and bronze

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Curtain Wall Materials/Assemblies

• Glass and mullions- prefab or glass set onsite

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Curtain Wall Materials/Assemblies

• Glass-Fiber-Reinforced Concrete (GFRC) Curtain
  Walls- alkali-resistant glass fiber
  admixturetensile strengthno steel reinforcing
  requiredweighs ¼ of conventional precast
  concrete panels.
• Exterior Insulation and Finish Systems (EIFS)
  Curtain Walls- a layer of plastic foam insulation
  covered with a reinforcing mesh and base/finish
  coat of stucco. Can be installed over a CMU
  backup wall or steel studs and water-resistant
  sheathing. (aka Drive-it)

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References Cited

• Andres, Cameron K. and Smith, Ronald C. (2001).
  Principles and Practices of Commercial
  Construction (Sixth Edition). Prentice Hall New
  Jersey.
• Allen, Edward. (1990) Fundamentals of Building
  Construction Materials and Methods (2nd
  edition). Wiley Sons New York.