Durable Metal Roof Covers the country’s Most Sustainable, High-Altitude Building

Preserving a piece of American history, the new Pikes Peak Summit Complex replaces an old, bunker-like center on top of the 14,115 ft. “America’s Mountain” in Cascade, Colo. where poet Katharine Lee Bates was inspired to write the patriotic song “America the Beautiful” in 1893.

Designed to achieve both LEED Silver and Living Building Challenge certification and be the most sustainable, high altitude building in the U.S., RTA Architects and GWWO Architects had to highly scrutinize every product and material going into the 6,200 sq.-ft. visitor center to meet the materials petal requirements for the stringent seven-petal Living Building Challenge.

Further, with below freezing temperatures the majority of the year, heavy snow loads of 125 lbs per sq. ft. and winds reaching 170 mph, the Colorado Springs roofing contractor Weathercraft needed a highly durable and robust metal roofing system to withstand the extreme weather conditions.

Fortunately, Drexel Metals had performed some unusually high wind testing for its DMC 200S with a custom clip-on attachment system AND the system was free from Red-listed chemicals. After submitting all data on the roof system’s components for LBC review and acceptance—including the sealants, butyl, clips, roof panel, backplates, seam sealant, snow guards and sheets—the roofing system could then be designed and fabricated.

The 22-gauge, 2-ft. mechanically seamed Corten steel standing seam panels sit on top of a precast concrete floor, wall and roof structure. With a 1/12 pitch in a trapezoid shape, the metal panels run as long as 115 ft., and are tied into a ¼-in. plate gutter system running around the roof perimeter.

Contributing to the building’s high rooftop R-90 insulation, high-density EPS insulation with ¾-in. plywood is mechanically attached to the structural metal decking. The roofing contractor also installed a layer of Metshield ice and water shield.

The next step in the installation process was marking the clip layout on the underlayment as the roof required fixed clips. By providing a point of fixity for the metal panels, this allows for thermal movement toward the eave and peak line. The Drexel panels were then lifted by crane and installed with fixed and continuous clips. The clip systems reduce panel stress caused by changes in temperature and help maintain a smooth, uniform appearance.

Each panel was seamed right after installation to protect against wind damage. After completing the peak detail, an S-5 ColorGard snow guard system with 199 clamps was installed. The snow retention system is custom designed and anodized in bronze to match the roof color.

Structurally, the roof is reinforced with superimposed loading of 540 lb/ft2, with a dead load of 390 lb/ft2 and a live load of 150 lb/ft2. The project team also designed the roof to keep boulders away from the walkways on the site and dowels were installed to prevent the upper concrete form from sliding off the roof.

High Altitude Sustainability

The Pikes Peak Summit Complex, which is connected to the U.S. Army Corps Engineers’ new High-Altitude Research Laboratory on the mountain top can be accessed by car or via the modernized cog railroad, originally built in 1891, to travel nine miles up the mountainside.

The north side of the Summit Complex sinks into the mountain to take advantage of the ground’s thermal mass for insulation. The subtle design also allows the mountain itself to take center stage.

“We wanted to create an iconic experience, not an iconic building,” RTA Principal Stuart Coppedge, FAIA, LEED AP, told Civil Engineering magazine. “You can’t out-mountain the mountain. It’s all about the total experience, not some architectural monument.”

On the south side, a high performance curtain wall system with electrochromic glazing in the lobby space enables the building to benefit from passive solar heating, which is tied into a radiant floor system.

While the harsh climate made a rooftop solar panel installation unviable, the Complex is able to import PV renewable energy from another location to make the building net electricity positive.

The building also features rainwater and blackwater collection, treatment and reuse systems. The rainwater supplements municipal water for potable needs and the graywater and blackwater is be treated onsite and reused for toilet flushing.

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