Steeped in roofing

The Durable Slate Company, Columbus, Ohio, restores historical Steeple Square in Dubuque, Iowa

  • Aerial view of the completed steeple
  • The Durable Slate Company crew
  • The custom-designed scaffolding
  • Workers used a crane to remove decorative elements to be used as molds
  • Work in progress
  • The completed steeple

Built between 1864 and 1867, St. Mary’s Catholic Church in Dubuque, Iowa, served as an economic, social and educational center for German-immigrant parishioners. For almost 150 years, the church was a central meeting space for working-class citizens. It was a gateway for newcomers to Dubuque, hub for downtown neighborhoods and source of community pride.

Faced with debt and declining membership, the church closed in 2010 and was set for demolition until community leaders united to form Friends of St. Mary’s, a nonprofit organization, to save the iconic landmark and revitalize the neighborhood. Renamed Steeple Square, the buildings and grounds underwent a $2.2 million restoration.

The project’s general contractor, Gronen Restoration, Dubuque, selected The Durable Slate Company, Columbus, Ohio, to help rebuild Steeple Square’s Gothic-style bell tower and steeple.

“Because of The Durable Slate Company’s reputation for impeccable craftsmanship and passionate commitment to honoring historical integrity, Gronen Restoration chose The Durable Slate Company to manage the sheet-metal work,” says Shawn Hilborn, operations and construction manager for Gronen Restoration.

Preserving a landmark

In April 2018, The Durable Slate Company crew began work on Steeple Square. At 211 feet high, the steeple is one of the tallest structures in Dubuque. To work safely at this height, The Durable Slate Company workers helped design and install a scaffolding system.

Once scaffolding was erected, workers removed the sheet metal down to the wood plank roof deck and used a crane to carefully remove decorative elements to be used as molds to fabricate matching copper pieces.

Because of the building’s age, the materials were tested for asbestos and lead.

“Anyone who specializes in restoration work knows there is a good chance one or both of these hazardous materials may be present,” says Gary Howes, chief operating officer for The Durable Slate Company. “The test results were positive for lead. But fortunately, all our workers are trained and certified in lead awareness. We followed proper protocols and wore personal protective equipment throughout the demolition phase to ensure the safety of our workers, other trades working as well as the public and environment.”

The Durable Slate Company workers repaired and/or replaced deteriorated roof deck sheathing and applied Owens Corning Titanium® Synthetic Underlayment to the roof deck. To create new flat-lock copper panels, The Durable Slate Company craftsmen used 15,000 pounds of 20-ounce copper and handmade each panel with a cleat to allow for expansion and contraction.

“We know how copper works—how it moves, expands and contracts,” says A.J. Davis, project manager for The Durable Slate Company. “We put in time and research to find the best methods that will ensure a long-lasting copper installation. We strive for quality.”

The Durable Slate Company craftsmen used soldering irons and lead-free solder to sweat some of the panel joints to ensure a watertight fit.

Working with Chicago Metal Supply Inc., The Durable Slate Company crew used an additional 10,000 pounds of copper to custom-fabricate dozens of decorative pieces such as aprons, pans, valleys, fascia, dormers, gable ends, finials and gold leafing.

In 2015, Steeple Square was added to the National Register of Historic Places, requiring all replicated details to be historically accurate. Once on-site, The Durable Slate Company craftsmen made numerous modifications to maintain the building’s historical nature.

Workers also installed a lightning-protection system on the steeple.


In addition to challenges of working on a steep structure, Steeple Square is located near the Mississippi River, where windy conditions made handling materials difficult.

“Because of this, we added netting to the exterior of the scaffolding to help reduce the effects of the wind, but on the days when the wind was excessive, we had to quickly roll up the netting so as not to have too much wind resistance against the scaffolding,” Davis says.

Adding to challenging working conditions, the project had to be completed before winter because of the high cost to maintain the scaffolding.

“Because of the large percentage of custom fabrication, it was essential to have the crew working as efficiently as possible,” says Jason Lee, foreman for The Durable Slate Company. “We accomplished this by having a highly skilled crew that was committed to working six and sometimes seven days a week, taking lunch breaks up on the scaffolding, and planning for rain and wind days when decorative pieces could be modified in our on-site shop. The steeple is an ornate and iconic structure, and to be a part of its preservation was an honor.”

Steeped in accolades

In October 2018, The Durable Slate Company crew completed work on Steeple Square. A Dubuque icon since the 1800s, the revived Dubuque skyline landmark now serves as a beacon for affordable housing, educational training, recreational programs, celebrations and community empowerment.

“We are restorationists at heart, so when we get a chance to preserve or restore an important piece of architecture like Steeple Square, we get excited,” Howes says. “We feel a huge amount of pride knowing our work will last for many generations to come.”

For its exceptional work on Steeple Square, The Durable Slate Company received a 2020 Gold Circle Award from the Roofing Alliance in the Outstanding Workmanship category and a North American Copper in Architecture Award from the Copper Development Association. In addition, The Durable Slate Company is the first U.S. company to win a prestigious International Federation for the Roofing Trade IFD Award in the Metal Roofing category.

“The Durable Slate Company’s team played an integral, supportive role in helping Gronen Restoration keep a tight schedule that delivered the project on time and under budget,” Hilborn says. “The restored steeple is a step toward a restored sense of community identity in one of Dubuque’s most vulnerable neighborhoods and will enable the campus to reclaim its role as a center of community support. The neighborhood and community benefit from its completion. I thank The Durable Slate Company for its commitment to excellence in this endeavor.”

Chrystine Elle Hanus is Professional Roofing’s associate editor and an NRCA director of communications.

Project name: Steeple Square
Project location: Dubuque, Iowa
Project duration: April—October 2018
Roof system type: Copper
Roofing contractor: The Durable Slate Company, Columbus, Ohio
Roofing manufacturers: Auburis, Buffalo, N.Y.; Chicago Metal Supply, Chicago; Owens Corning, Toledo, Ohio; The Corken Steel Products Co., Covington, Ky.



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