CASS Custom Architectural Sheetmetal Specialists - Detroit, MI

NEWS ARTICLE - SMACNA Architectural Metal - APRIL 2009 - Volume 15, Number 1

Read The Full Story Below.

Custom Copper Dome Fabrication & Restoration

A Historic National Landmark is Restored!

06-Copper-Dome Fabrication Replacement Cranbrook-Institute Observatory Tower by CASS Sheetmetal Detroit MI

Cranbrook Observatory Tower Dome Restoration
Bloomfield Hills, MI.

Gleaming Historic Copper Cupola
Delivered in Record Time!

Working with a daunting schedule, CASS Sheetmetal custom fabricated and installed a shiny new, historically accurate copper cupola on top of the Cranbrook Observatory Tower, a national historic landmark in Bloomfield Hills, MI.

“This was an extreme task that involved much cooperation and effort between our subcontractors and the trades,” said Glenn Parvin, CASS Sheetmetal president. “we kept to a tight schedule.” The company’s challenge was to complete and install the dome in two months working around the community’s summer calendar.

The work was part of a combined project to rebuild the tower’s deteriorating copper cupola and to restore the Ludowici clay tile roof of the Cranbrook Library, both part of the venerable Cranbrook Educational Community. The tower was built in the 1920’s and originally served as a functioning observatory. The years and weather had taken their toll on the structure. Its existing copper cladding, which was simply riveted to the structural steel, had leaked for years..

Custom Copper Dome Fabrication & Restoration - Cranbrook Institute

The years and weather had taken their toll on the structure. Its existing copper cladding, which was simply riveted to the structural steel, had leaked for years. Wind and water damage caused galvanic corrosion and severely rusted the structural steel.

CASS which specializes in custom sheet metal fabrication, laid out a schedule that included the dates of deliveries and critical activities. The firm participated in the design concept to build the structure and then, to save time, worked with its partners to construct the structural steel, wood decking and copper cladding on the ground. The self-performing init of the Skanska construction group built the plywood structure under the copper roof.

Eight CASS employees as well as three carpenters and laborers were on the job nine hours a day, six days a week to complete the work. The steel subcontractor, Davis Iron Works of Commerce Township, even sent a driver to Chicago who waited for the galvanizing to be done on the steel, Mr. Parvin noted.


Putting finishing touches to the newly fabricated copper dome.


CASS crew hoisting the replicated copper dome into position.


Weather damaged and deteriorated original copper dome.


Placing new Copper Dome into final position.

The team began work on June 11, the Monday after the school doors closed, and operated around graduation ceremonies, and alumni weekend and other events. Then, on August 13, the structure was ready. They hoisted the burnished 5,800-pound dome 80 feet high and installed it on top of the tower-two days ahead of schedule.

The company strove to be true to the building’s historic ontent. “The ower was nonfunctioning, yet needed to look as it did originally,” Mr. Parvin said. “CASS came up witha button-punch panel to emulate the rivot pattern without actually penetrating the panels. The new dome was designed to be watertight with a flat-lock seam graduated panel system, with all panels above the 2-inch, 12-pitch mark on the top soldered watertight.”

Mr. Parvin credits the project’s success to their winning partnership with the same team, Skanska and Davis, who have worked together to complete another school’s historic copper roof restoration.

Custom Copper Domes, Cones, Caps & Metal Fabrication Design by CASS Sheet Metal – Detroit, MI