Lecture 22- Exterior Cladding Systems a.k.a skins

ARCH 330

Materials & MethodsFall 2008

Cladding/ Curtain Wall

• Constructed in Place• Prefabricated

CladdingA.K.A

SkinCurtain Wall – glass + metal systems

Cladding• Non-load bearing exterior wall enclosure.• Most visible, most subject to attack by

natural forces.

• Separates indoor environment from outdoors in such a way that the indoor environment can be maintained at a level suitable for the building's intended use.

Primary Functions of Cladding• Keep Water Out• Prevent Air Leakage• Control Light (heat, glare, ultraviolet)• Control Radiation of Heat • Control Conduction of Heat• Control Water Vapor • Control Sound

Secondary Functions of Cladding• Resist Wind Forces: • Adjust to Movement:

Thermal expansion and contraction, Moisture expansion and contraction, Structural deflections.

• Resist Fire• Weather Gracefully

Forces that Move Water

• Gravity• Momentum • Surface Tension • Capillary Action • Wind/ Air Currents

Rainscreen Principle

• Let wind pressure differences between the outside and inside neutralize themselves

PECPressure Equalization Chamber• Pressure equalized wall design • Airtight barrier at the internal side• Rainscreen - loose fitting jointed layer • Current of air can pass back and forth

through the unsealed joints.

Sealant Joints in Cladding

• Fill/seal the joints • Prevent flow of air and/or water • Permit assembly tolerance• Permit movement

Design Process - Prefabricated (a) Curtain wall manufacturer selected and

made a part of the building design team from the first stages of the project.

 (b) The architect prepares a rough design and

performance specification and submit these to several manufacturers for proposals.

STICK

1. Anchor2. Mullion3. Horz rail4. Spandrel panel5. Horz rail6. Glass

Constructed in PlaceStiffening Method• Steel Sub Frame• Back-up Wall of Masonry• Back-up Wall of Light Gauge

Studs

PrefabricatedMethod of Assembly• Stick• Unit• Unit + Mullion• Panel• Column Cover + Sprandrel

Masonry

• Constructed in place• Prefabricated

Metal + Glass

• Prefabricated

Structural Glass

Gehry - Guggenheim

Nicholas Grimshaw and Partners Ludwig Erhard Haus Financial Centre