Sheet metal & Air Conditioning Contractors’ National Association


Latticework metal dome on San Diego’s new Central Library catches the light

Jun 12, 2015

Central Library, San Diego
Rob Wellington Quigley, FAIA and Tucker Sadler & Associates
California Sheet Metal Works Inc., El Cajon, Calif.

Dome & Sunshades OverviewSan Diego’s new nine-story Central Library sports a 143-foot diameter dome, which makes it about the same size as the ones over the Pantheon in Rome and the Duomo in Florence. Beyond size, the landmark building’s dome stands out for its design—a metal latticework that allows light to filter through to the three-story reading room beneath it—and it is quickly becoming a new symbol for the city.

DomeTo create that dome, SMACNA contractor California Sheet Metal Works Inc. (CSM) of El Cajon, Calif., used 3-D modeling and provided 1,200 custom-fit, marine-grade, perforated aluminum panels requiring 2,400 different compound miter cuts. The panels were secured to the compound radius steel structure using more than 5,000 bracket attachments, which had to allow for thermal movement. Each connection point required 9,600 attachment bolts and isolation washers.

Dome_close-upThe new library is 497,652 square-feet and nine-stories and is located in downtown San Diego. 

“Installation challenges were numerous,” says CSM President Joe Isom, “including site logistics, meeting city-mandated small business goals for material acquisition, and interfacing with multiple trades.” For example, CSM had to help engineer a scaffolding structure to fit within the dome’s steel structure and build a custom lifting elevator for parts, with multiple levels to allow installation of panels. Further, CSM needed to design a hoist to install steel support members from the inside of the building when weight and size made it not feasible to install them from the exterior.Dome and library2

CSM’s involvement in the project was not limited to the dome. The contractor fabricated and installed 1,500 additional marine-grade perforated aluminum panels as building sunshades, 350 hot dipped galvanized steel support members including imbeds, and 36,000 bolts with isolation washers. The project included installing four-sided cooling vent louvers and 2,000 perforated ceiling swoops, along with the brackets required to meet seismic requirements, and the auditorium building roof system.

Preforated Aluminum SunshadesFor the auditorium building, CSM provided a lead-coated copper radius batten seam roof system with internal drainage, fascia, and soffit. They also provided a mechanical roof screen that used more of the marine-grade perforated panels and hot-dipped galvanized steel support members.   Lead Coated Copper Roof & Mech Screen

At the library’s café with its round roof, CSM created a custom radius gutter that included a double-wall stainless steel planter with full drainage system and perforated security screens.Radius Aluminum Lattice

Moving inside, CSM fabricated an ornate aluminum lattice design feature with a 12,000 linear-foot radius on seven floors of the building. They also created a lead-coated copper sound baffle at the auditorium stage as well as ceiling swoops in the auditorium interior. In addition, the contractor designed and fabricated unistrut support hangers on the library’s lattice design features and aluminum backbones to meet seismic design requirements.

 Perforated Swoops   
    Perforated Swoops 2

The project completion took more than two years.

 Copper Sound Baffle2    
CSM received CAL-SMACNA’s Tom Guilfoy Memorial Craftsmanship of the Year
    Utilities photo2

Award, architectural category, for its work on the library. In addition, the library’s general contractor presented CSM with a safety award for its outstanding safety record and innovative safety solutions.

For more information on the San Diego Central Library, visit these links:

California Sheet Metal Works Inc.
San Diego Central Library Project Overview
San Diego Central Library Photos