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ARCH 2614/5614 Lecture notes

Jonathan Ochshorn

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Wall sections — precast and metal panels, and EIFS

Both precast and metal panels can be used as cladding; metal panels usually are fastened to some kind of back-up system (either metal studs or CMU); whereas precast panels are often attached directly to the structure itself.

Metal panels

Metal panels used as cladding fall into two main categories:

  1. sheet metal, flat or corrugated, attached to a back-up system; and

  2. "sandwich" panels consisting of two thinner metal sheets over a rigid core.

In the latter case, the core can be insulating or not (e.g., foamed plastic versus honeycombed paper). An example of the use of metal panels is shown in the image below (left): Richard Meier's Getty Center (photo by J. Ochshorn); the image at right shows manufacturer's product literature for a proprietary metal panel system. Notice the concealed connection to a back up system (in this case a horizontal angle).

Meier's Getty center showing metal panels at soffit and wallmanufacturer's details of metal panel

manufacturer's details of metal panel
Manufacturer's recommended detail options at parapet coping.

FormaBond Metal Composite Wall System
FormaBond Metal Composite Wall System (image source)

Commercial rain screen metal panel system (over insulated metal panel back-up wall):
Centria Metal Panel Wall System
Centria Metal Rain Screen System (with insulated metal back-up wall) (image source)

An alternate approach uses sheet metal in a less "formal" manner. Many examples can be found in the work of Frank Gehry, including his project at 340 Main St. in Venice, CA shown below (left). In this case, each panel is just a sheet of metal bent at the edges over the adjacent panels so that the fasteners are hidden, and water is kept out, much like a shingle. The two strategies are contrasted (at right).
Gehry's 340 Main St., Venice showing metal panelscomparison of gehry's and meier's use of metal panels

Gehry's 340 Main St., Venice showing metal panelsMeier, Weill Hall, Cornell
Frank Gehry, 340 Main Street, Venice, CA (left) contrasted with Richard Meier, Weill Hall, Cornell (right)—photos by J. Ochshorn.

Meier, Weill Hall, Cornell
Meier, Weill Hall, Cornell
Richard Meier, Weill Hall, Cornell, under construction

Other Cornell metal-clad buildings:

Duffield Hall, Cornell
Duffield Hall, Cornell
Zimmer Gunsul Frasca Architects, Duffield Hall, Cornell

Statler Hall addition, Cornell
KSS Architects, Statler Hall addition, Cornell, under construction

More examples of metal panels

The images below show the overlapping metal panels used at Gehry's Disney Concert Hall in Los Angeles (left), and a detail of their attachment to a metal sub-structure (right). Both photos by J. Ochshorn.

Gehry's disney concert hall, showing metal panelsGehry's disney concert hall, showing detail of metal panel attachment

A more "industrial" type of panel is the corrugated variety, shown below. Note that these types of panels have also been appropriated for Architecture (with a capital "A"). See, for example, Gehry's project at 39 Horizon Ave. in Venice, CA (right).
corrugated metal panelsgehry, 39 horizon avenue, venice, CA showing use of corrugated metal panels

Mecanoo, Library, Netherlands
Mecanoo, Openbare Bibliotheek, Almelo, Netherlands (A href="http://ecoastarchreview.com/2010/09/09/intriguing-earth-architecture-80/">image source)

Central Artery Tunnel Ventilation Building Boston
Rainscreen detail: Central Artery Tunnel Ventilation Building, Boston

Formawall rainscreen detail
Rainscreen detail: Formawall

Alpolic copper composite ad
Alpolic copper composite ad (architectural brochure PDF)

Gehry's Beekman Towers, NYC (2010)

Gehry, Beekman Towers, NYC Gehry, Beekman Towers, NYC

Gehry, Beekman Towers, NYC

Gehry, Beekman Towers, NYC
Gehry, Beekman Towers, NYC (images from Architectural Record, Sept. 2010)

Design process (per AR Sept. 2010):

*A parameter is a variable to which other variables are related, and these other variables can be obtained by means of parametric equations. In this manner, design modifications and creation of a family of parts can be performed in remarkably quick time compared with the redrawing required by traditional CAD.

Insulated metal cladding fires

See: Lstiburek, BSI-098: Great Fire of London

insulated metal cladding panel fires: OMA, CCTV hotel (Beijing) and Grenfell (London)
Insulated metal panel exterior cladding fires: Grenfell (left: London, 2017); CCTV Mandarin Oriental Hotel by OMA (right: Beijing, 2009)

Precast panels

Precast concrete panels can be load bearing or used just as non-load-bearing cladding. The latter use is primarily discussed here. Typical cladding panels are attached directly to the structure, rather than to a back-up wall or sub-structure as is usual for metal panels. An excellent reference is the PCI design handbook: precast and prestressed concrete. Characteristics of precast panels are as follows:

An example of a building with precast panels is shown below: Malott Hall at Cornell, designed by Levatich, Miller, Hoffman (photo by J. Ochshorn)

Malott Hall at Cornell with precast cladding panels, Levatich, Miller, Hoffman Architects

Precast cladding being installed on an East side building in NYC (photo by J. Ochshorn, July 2017)

NYC precast cladding under construction

Tilt-up concrete Tilt-up is a kind of site-cast/precast hybrid, in that wall panels are cast on site, but not in place. Typically, they are cast on a horizontal floor slab, which creates an ideal base for a flat wall panel, and eliminates much of the high cost due to formwork. After curing, the wall panels are then "tilted up" into place. An early tilt-up pioneer was early 20th-century California-based architect Irving Gill. Modern techniques allow for more flexible designs.

Gill, tilt-up example
"Gill used tilt-slab concrete construction for La Jolla Woman's Club (1912-1914)" (source: Sarah J. Schaffer)

modern tilt-up example
Grandview Business Centre, under construction (source: The Construction Specifier, Jan. 2014, p. 14)

Fiber-reinforced plastics

Petroleum-derived polymers, already widely used in non-building applications, have made an appearance as architectural cladding. See this article about the addition to the San Francisco Museum of Modern Art: "Architect Snøhetta designed the building with an unconventional white exterior that includes large bulges and small ripples inspired by the bay and nearby waters. The architect's liberal creativity was made possible by using a facade comprised of a synthetic fiber reinforced polymer (FRP) composite with added natural aggregates. The material, uniquely formulated by fabricator Kreysler and Associates, can be molded in an infinite amount of shapes and is considerably more cost effective and lightweight compared to traditional materials. Kreysler and Associates is molding the fire resistant material into 700 unique panels approximately 3/16th of an inch thick. Each panel will be fastened to an exterior aluminum frame and when completed will represent the largest installation ever of an FRP. Deliveries and installation of the panels are slated to start later this year [2014]."

SFMoMA FRP facade
SFMoMA addition using FRP cladding panels (image source)

SFMoMA FRP facade
FRP cladding panel prototype (image source)

EIFS

Diagram showing EIFS system
Diagram showing EIFS "PM" system (source: Progressive Architecture, Oct. 1989)

EIFS (pronounced eef-us), stands for Exterior Insulation and Finish System and consists of cementitious lamina applied over insulation, thereby solving the problems of insulation and cladding within one thermally-efficient and inexpensive system. The EIFS is applied over a substrate which can be virtually any assembly that provides a flat surface onto which the EIFS is adhered or mechanically attached. EIFS is a classic "barrier" system without a second line of defense, although various proprietary "rain-screen" variations are marketed (including the one pictured in the image below, at right).

Brief history

Advertisement showing EIFS system
Advertisement for EIFS system: Michael Graves, West Virginia University

The images below show a schematic cross-section through EIFS (left) and an advertisement for a proprietary EIFS product (right) showing the same layers.

schematic cross-section of EIFS showing lamina, insulation, and substratedryvit advertisement showing EIFS layers

Substrate

Virtually anything can be a substrate for EIFS, including existing cladding systems. Examples include:

In the image below (Stewart Avenue, Ithaca, NY), insulation boards are being mechanically fastened to an existing CMU wall (photo by J. Ochshorn):

EIFS insulation boards being fastened to a substrate consisting of an existing CMU wall

EIFS mesh embedded in base coat, Stewart Ave., Ithaca, NY (photo by J. Ochshorn) EIFS mesh embedded in base coat,
EIFS mesh embedded in base coat: Stewart Ave., Ithaca, NY (left, photo by J. Ochshorn); application with trowel (STO Industries, Atlanta, GA)


Video shows base coat of EIFS being applied to the basement of an apartment building at 201 College Avenue, Ithaca, NY, Stream Collaborative, Architects (video by Jonathan Ochshorn, August 2017)

EIFS system types

There are two main EIFS types, which can be compared to traditional stucco. In the descriptions that follow, "mineral-based" refers to the use of portland cement.

PB: polymer-based

PM: polymer-modified

MB: mineral-based (i.e., not EIFS)

Comparison of PB and PM sEIFS systems
Comparison of PB and PM sEIFS systems

The image below shows a large plastic washer, used where the insulation boards are mechanically fastened to the substrate with long screws (which would otherwise punch through the soft insulation board).

plastic washers used to mechanically fasten insulation board EIFS fasteners (STO Industries)

EIFS fasteners (photo by J. Ochshorn)
Plastic washers screwed through insulation boards into substrate (photo by J. Ochshorn)

EIFS fasteners (photo by J. Ochshorn)
Insulation board is cut around pipe: proper flashings not necessarily installed by Mr. Hilfiger (photo by J. Ochshorn)

Types of insulation commonly used with EIFS

Two primary insulation types are used, corresponding to the two EIFS system types (both are Rigid Cellular Polystyrene, or RCPS):

EPS: (molded) Expanded Polystyrene

XPS: Extruded (expanded) Polystyrene

Comparison

Aesthetic joints
Using a hot groover (left), lines, with various profiles, can be "drawn" on the surface of the EIFS, as shown in section (right) with a "V-groove;" an application of such aesthetic lines is shown on College Avenue, Ithaca, NY (photo by J. Ochshorn)

Aesthetic grooves in EIFSAesthetic grooves in EIFS

Aesthetic grooves in EIFS, College Avenue, Ithaca, NY  EIFS groove shapes (photo by J. Ochshorn)

Projecting graphics: The opposite of "aesthetic joints" (not that they're not equally "aesthetic")

Projecting graphics in EIFS
Projecting graphics using rigid insulation pieces glued together

Examples of EIFS

EIFS at Performing Arts Center, Cornell
EIFS (instead of brick?) at the Schwartz Center for the Performing Arts, Cornell, James Stirling/Michael Wilford

EIFS cylinders
EIFS column shapes

EIFS building cladding
EIFS on unidentified building simulating some sort of, well, something.

Criticism of EIFS

Numerous problems were experienced, especially in residential contexts, with EIFS, mostly because of inadequate attention to detailing at penetrations and terminations (e.g., windows and doors, or intersections with other materials). A few points should be observed:

EIFS building on cover of Walls & Ceilings magazine
EIFS at Furnitureland South Mart, Jamestown, NC featured on cover of Walls & Ceilings trade journal (see video links).

EIFS Longaberger Building
Longaberger Building, Newark, Ohio, 1997 (EIFS with galvanized steel "handles."

Other variations

fake brick
Spray-on fake brick.

Polyurethane coated EPS systems

A similar, but even thinner insulation-based cladding system can be manufactured using EPS boards (see above) coated with a thin layer of polyurethane and a thin, textured, mastic finish:

polyurethane-coated EPS

polyurethane-coated EPS
polyurethane-coated EPS