The Calcaire House Meets Strict Energy Codes — and Does it in Style

The residential compound is made up of five interconnected buildings and features both gabled standing seam metal roofs and low-slope TPO roofs. Photos: S-5!

The Calcaire House is a 15,000-square-foot modern Colorado single-family residential compound consisting of five interconnected buildings. Floor-to-ceiling glass connects the interior space to the exterior landscape, offering spectacular views of the Boulder Flatirons. A combination of exposed timber, stone and steel structural design elements, and exposed custom roof trusses complement the gabled standing seam metal roof.

Boulder Roofing Company and The Solar Revolution were charged with installing a metal roof and solar array with more than 60 kilowatts of solar dispersed over multiple rooftops. Boulder Roofing installed both standing seam metal and TPO roof systems on the project. Crews installed approximately 12,000 square feet of 14-inch, 24-gauge panels from Drexel Metals in traditional black over Titanium PSU30 high-temp peel and stick underlayment.

They also installed 3,000 square feet of 60-mil Versico TPO over low-slope areas. The TPO was adhered to quarter-inch DensDeck Prime over tapered EPS insulation. Boulder Roofing fabricated and installed custom flashings and coping, and also installed an S-5! snow-guard system incorporating the S-5! ColorGard bars, S-5-S Mini clamps, SnoClip IIs, and VersaClips.

The Energy Challenge

The city of Boulder has strict energy codes in place and requires all new construction to meet a certain level of efficiency. The requirements are based on the square footage of the home and are more stringent on larger homes — the larger the home, the more efficient it needs to be. The goal is to have a net-zero home, not taking energy from the grid, and the only way for a larger home to achieve this is with solar. A modest home or small addition might only require about 2 kilowatts. A large home might require 20-30 kilowatts.

The most optimal rooftops for solar were also the most visually prominent, and the homeowner was concerned about aesthetics. These concerns were alleviated after seeing a small-scale mock-up of the S-5! PVKIT 2.0 solution combined with an all-black solar module.

In addition, the area is considered a high-wind area and would require a study to account for windspeeds, as the solar installers could only rely on the roof itself and its attachment to the wood sheeting when attaching solar panels using S-5!’s zero-penetration system.

Another difficulty was finding a viable path to route the energy created by the solar panels back to the point of connection with the home’s distribution. The Solar Revolution worked with the builder and the architect, and analyzed photos and design plans to find ways to conceal the conduits. They ultimately found a viable path that was aesthetically pleasing, code compliant and cost-effective.

The Solution

The Solar Revolution installers utilized S-5!’s PVKIT 2.0 to build the solar array. The installation team started at ground level prepping S-5! PVKIT MidGrabs and EdgeGrabs. Another team member prepared the solar modules by installing the power optimizers and managing the various wires. By completing this work on the ground, the roof crew could focus on setting modules, and it minimized their time in harnesses on a steep metal roof. The solar installers prefer to install modules starting with the bottom row and working up. Extra care is taken when aligning the first row. This precision allows for subsequent rows to drop into place on the S-5! PVKIT MidGrabs.

The Solar Revolution installed a solar array that provides more than 60 kilowatts of power.

“The Solar Revolution has been utilizing the S-5! PVKIT 2.0 solution since it first hit the market,” says Doug Claxton, CEO of The Solar Revolution. “Hands down, it is the best solar mounting solution for metal roofing of any description. At first, we were a little worried about wire management and installing in landscape, but those worries were overcome with our first installation. It’s a piece of cake.”

Long-Term Outlook

With the S-5! PVKIT 2.0, the Calcaire House was able to meet the city code requirements for solar and establish itself as an energy-efficient, net-zero home. Because the PVKIT comes in black, it matched the roof nicely, pulling together all of the design elements in an aesthetically pleasing, cost-effective manner — saving the customer time and money on installation and materials.

TEAM

Architect: Surround Architecture, Boulder, Colorado, www.surroundarchitecture.com

General Contractor: Harrington Stanko Construction, Niwot, Colorado, www.harringtonstanko.com

Engineer: Anthem Structural Engineers, Boulder, Colorado, www.anthemstructural.com

Roofing Contractor: Boulder Roofing Company, Boulder, Colorado, www.boulderroof.com

Solar Installer: The Solar Revolution, Boulder, Colorado, www.thesolarrevolution.com

MATERIALS

Metal Roof: 175SS 14-inch, 24 gauge panels, Drexel Metals, www.drexmet.com

Underlayment: Titanium PSU30, Owens Corning, www.owenscorning.com

TPO Roof: 60-mil Grey TPO, Versico, www.versico.com

Cover Board: DensDeck Prime, Georgia-Pacific, www.buildgp.com

Solar Attachment: S-5! PVKIT 2.0 in black with S-5-S Mini Clamps, www.S-5.com

Snow Guards: S-5! ColorGard, S-5-S Mini Clamps, SnowClipIIs and VersaClips

Boulder Lumber Warehouse Needed a Roof Built to Last in Tough Conditions

Boulder Lumber’s 19,512-square-foot warehouse needed a roof that could withstand high winds and extreme weather. Photos: Versico

Since 1927, Boulder Lumber has served the building contractors of Boulder, Colorado, providing lumber, millwork, doors, windows, decking, and other building materials. In 2019, Boulder Lumber’s built-up tar and gravel roof needed to be replaced, largely because of damage caused by wind events. The wood nailer at the perimeter had become dislodged and the built-up system had begun to peel back from the concrete deck.

The city of Boulder is located in the Boulder Valley where the Rocky Mountains meet the Great Plains. Wind uplift is a major concern for buildings in this area, as high winds come off the canyons from the Rocky Mountains. The wind intensifies as it travels over buildings, which creates high pressure at roof perimeters. Winter conditions in Boulder range from mild to bitterly cold, with an average of 88 inches of snow per season.

The unpredictable weather in northern Colorado shortens their roofing season compared to other areas in the country. Winters can be very cold, and the Boulder area receives an average of 88 inches of snowfall per season.

Key Priorities

When selecting a new roof for the 19,512-square-foot warehouse, Boulder Lumber was looking for something with excellent wind uplift resistance to avoid the problems they’d experienced in the past. They also wanted a system that could be installed quickly in a variety of temperatures, since the weather in Boulder can be very unpredictable and the labor market is tight. Lastly, they wanted to work with a skilled, dependable roofer who would get the job right the first time around.

Boulder Lumber enlisted Black Roofing to install a tough, durable roofing system that would be able to withstand the high wind uplift pressures at the perimeter of the roof. Black Roofing suggested Versico’s RapidLock Roofing System due to the ability of this roofing system to perform well in this environment.

The RapidLock Roofing System uses Velcro Brand Securable Solutions’ hook and loop attachment method to provide a fully adhered system without adhesives. The backing on the VersiFleece membrane attaches to a specialized facer on the insulation boards.

RapidLock roofs are designed to be quick and easy to install and there are no installation temperature restrictions, making this system an ideal fit for the Boulder Lumber project. According to the manufacturer, RapidLock installations provide up to 80 percent labor savings compared to traditional bonding adhesive and up to 25 percent labor savings compared to a traditional VersiFleece system.

The Installation

The 20-year-old existing built-up roof system had to be torn off to the structural concrete deck, including scraping residual asphalt.

Because of the damage to the concrete deck, the existing wood nailer was deteriorating. Black Roofing decided to use Metal-Era’s Eliminailer to provide a strong connection on the perimeter and protect the roof against high winds.

Black Roofing used CAV-GRIP 3V to prime the deck. The product promotes adhesion and can be used in temperatures as low as 15 degrees Fahrenheit when used as a primer.

Flexible DASH Adhesive was used to adhere a layer of 1-inch SecurShield Polyiso insulation to the concrete deck. Alan Nedelea with Black Roofing says, “We used Flexible DASH to eliminate any of the fasteners that would have been needed to penetrate into the concrete deck, and also to provide a good adhesion for the wind uplift required for this system.”

A layer of 6-inch SecurShield HD RL was then adhered to the base layer. The product has a specialized facer that allows for membrane attachment without using adhesives.

VersiFleece RL EPDM was attached to the SecurShield HD RL. Black Roofing simply positioned the RapidLock EPDM sheets, removed the release liners, then broomed and rolled the membrane into place. Once the job was complete, a 15-year, 55-mph wind speed warranty was issued.

Nedelea cited the roof system’s wind uplift resistance and the lack of temperature restrictions for installation as the key reasons it was chosen for this project. He also pointed to RapidLock’s labor-saving benefits, which allow the roofing system to be installed in far less time than a traditional roofing system.

“This is the first RapidLock roofing system that Black Roofing has installed,” Nedelea says. “We really enjoyed doing this project.”

TEAM

Roofing Contractor: Black Roofing Inc., Boulder, Colorado, www.blackroofing.com

MATERIALS

Membrane: 115-mil VersiFleece RL EPDM RapidLock, Versico, www.versico.com

Insulation: SecurShield HD RL Polyiso RapidLock Insulation and SecurShield Polyiso, Versico

Metal Nailer: Eliminailer, Metal-Era, www.metalera.com