Roofing now in session

Douglass Colony Group helps renovate the Colorado State Capitol

  • Photos courtesy of Douglass Colony Group, Commerce City, Colo.
  • Workers reconstructed the gutter system
  • Craftsmen formed copper over plinthe blocks and soldered all joints
  • Buckingham® Slate tiles were installed above building entrances.
  • Aerial views of the roof systems under construction.

Constructed during the 1890s, the Colorado State Capitol houses Colorado's general assembly and its offices of the governor, lieutenant governor and treasurer. Designed by architect Elijah E. Myers to resemble the U.S. Capitol, the building was constructed with white granite and has a copper panel dome with a leaf gilded in gold to commemorate the Colorado Gold Rush.

The building's interior is adorned with Colorado rose onyx, a rare rose marble from a Colorado quarry. Stained-glass windows depict people and events related to Colorado's history, and the third-floor rotunda is decorated with portraits of U.S. presidents.

During the past few years, the Colorado State Capitol has undergone safety upgrades and interior and exterior renovations to maintain the 125-year-old building. In 2013, Douglass Colony Group, Commerce City, Colo., restored the iconic dome and regilded the leaf in 65-ounce gold.

In 2016, Douglass Colony Group returned to Colorado's state capitol to renovate the remaining roof areas to match the dome's grandeur.


In June 2016, Douglass Colony Group began working on Colorado State Capitol's second phase of roofing work. Because the tear-off process included asbestos removal, workers completed asbestos-awareness training before beginning the tedious tear-off process of removing multiple layers of previous roof system replacements.

The state capitol is located on a block with heavy pedestrian and vehicular traffic, so crews were challenged with strict time restrictions for deliveries and tight on-site access. In addition, the government building remained fully functional and occupied while the Douglass Colony Group crew worked diligently above the building.

"Crews had to be mindful to not tear off or perform any noisy activities during legislative sessions and always maintain an extreme awareness of people entering and exiting the building throughout the day," says Aaron Harvey, project manager for Douglass Colony Group. "The entire project also had to be phased to completely halt work during months when the general assembly was in session, making it easy to lose momentum."

Gutter system

As crews progressed with removing the gutters, they discovered large gaps in the worn-out framing. To fix the voids, workers reconstructed the gutter system using marine-grade plywood to support new copper gutter inlays.

"The copper inlays proved difficult to work with," says Jan Malec, Douglass Colony Group's superintendent. "Thermal movement made the material difficult to predict. A perfect fit was nearly impossible to accomplish, but with patience, skill and teamwork, we were able to complete the complex gutter system to the highest standards of quality."

Workers formed copper over plinth blocks (pieces of wood used as architectural support) and then fully soldered all the joints. All the metal for the project was prefabricated in Douglass Colony Group's off-site metal shop before being transported to the job site.

"The level of detail and workmanship seen in the copper gutter system created by our metal craftsmen is unbelievable," says Steve Bechtholdt, vice president of Douglass Colony Group. "Forming the copper over the blocks was no easy task, but the on-site crew executed the installation with an acute attention to detail. The entire system is fully soldered at all joints, which required our workers to be certified by the manufacturer and tested regularly."

Roof systems

Working closely with the architect and general contractor, Douglass Colony Group developed a 15- by 15-foot mockup of the roof areas that incorporated all elements and products before installing them.

Workers then installed Buckingham® Slate tiles above all building entrances and standing-seam Revere Z-T Alloy™ Coated Copper panels in FreedomGray® on the remaining roof areas.

In addition, workers installed four ornate vent hoods. Three of the hoods measured 14 feet high, and the fourth pinnacle hood measured 16.6 feet high. Scanning technology was used to record precise measurements on the existing structures so the new ones would be an exact fit.

To ensure the highest levels of quality, craftsmanship and safety, Harvey and Malec participated in meetings with the general contractor and other trades and conducted regular site visits throughout the project's duration.

Fully restored

As a result of diligence to safety and adherence to quality workmanship, in October 2017, Douglass Colony Group completed work on the Colorado State Capitol on schedule and with no recordable accidents. For its efforts to provide a safe job site, Douglass Colony Group was a finalist in the Roofing Alliance's 2018 Gold Circle Awards Safety Preparedness and Performance category.

"Douglass Colony Group has been fortunate enough to earn both projects at the Colorado State Capitol," Bechtholdt says. "The company takes great pride in all its work on the building, and both the dome and roof rank in the top five most unique and gratifying projects Douglass Colony Group has been involved in during the past 70 years. We are honored to have helped restore this Denver landmark."

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

Project name: Colorado State Capitol
Project location: Denver
Project duration: June 2016-October 2017
Roof system types: Copper and slate
Roofing contractor: Douglass Colony Group, Commerce City, Colo.
Roofing manufacturers: Buckingham® Slate Co., Arvonia, Va.; Revere Copper Products Inc., Rome, N.Y.


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