Category Archives: Outstanding Workmanship

NRCA Member Wagner Roofing Co. Restores Skylight Above 17-Story Bethesda Metro Center

BMC 1In January 2016, Wagner Roofing Co., Hyattsville, Md., began working on a skylight replacement project on the Bethesda Metro Center, a 17-story commercial office building located above the Bethesda Metro Station. The tower provides 368,000 square feet of rentable office space and is a hub for major financial institutions such as Merrill Lynch and Bank of America Corp.

The facility includes a 16-story atrium with composite skylight panels that had begun to deteriorate, resulting in significant leaks. The panels were eroding so much, glass fibers were being released and collecting in the building’s main gutter.

The project’s scope required Wagner Roofing to replace more than 200 fiberglass panels while reusing the skylight’s existing framing system, as well as a complete evaluation and overhaul of the perimeter gutter, flashings and water management systems.

To access the atrium to begin work, Wagner Roofing worked with Scaffold Resource LLC, Lanham, Md., to engineer a scaffolding system that would enable building operations to remain functional for the project’s duration while providing safe, secure access for personnel to work on the skylight and adjacent gutter systems.


Workers accessed the  12th floor by removing a skylight panel and installing a temporary hatch.

Workers removed one existing skylight panel on 12th floor and created a temporary “hatch” to install a work platform on the atrium’s underside to transport all material and equipment. This location was strategically chosen because the 12th floor communal balcony area was located about 7 feet below the base of the main built-in gutter and provided safe access for workers.

To provide easier access to the 12th floor balcony, a 160-foot-tall scaffolding system to support the mechanical hoist was erected on the building’s exterior and tied to the building’s floor slab edges through precast concrete cladding panels. This suspended scaffolding system provided workers with safe, sturdy access to the underside of the existing skylight system.

To protect pedestrians while work was being done on the skylight, workers erected side-walk shedding protection over the building’s lobby. In addition, all interior set up work was performed at nighttime to protect the building’s heavy pedestrian traffic during the daytime.

In addition, a cable system with debris netting was installed to provide placement for tools and construction debris that may escape the scaffolding system.

After the scaffolding and netting were securely in place, Wagner Roofing broke down, packed and transported all tear-off debris. Workers then carefully pre-measured all existing panels and developed a manufacturing cut list. Because of the atrium’s odd shape, nearly 100 skylight panels had to be made in different dimensions.

As old skylight panels were removed, workers replaced the new panels with new EPDM gaskets and retainer caps throughout the skylight’s interior areas.

Once the skylight panels were replaced, a new two-stage gutter system was designed to manage exterior rain water. Wagner Roofing also worked with Curtainwall Design Consulting Inc., Dallas, to develop a new liquid-applied reinforced polymer membrane waterproofing system that integrated properly with the new skylight system.

For exceptional preparation and outstanding work on the Bethesda Metro Center, Wagner Roofing received the 2018 Gold Circle Award in Innovative Solutions: Reroofing as well as the 2018 award for Safety Preparedness and Performance from The Roofing Industry Alliance for Progress.

This project is featured in the July 2018 issue of Professional Roofing magazine. Visit–07-01-2018/4272.




NRCA Member Black Roofing Inc. Installs Waterproofing Membrane on Denver International Airport Expansion


In October 2011, the Denver International Airport (DIA) launched the South Terminal Redevelopment Program to enhance the airport’s competitive standing as a leading global airport and increase overall passenger and aircraft-handling capacity.

The new construction project included a new Westin hotel with a conference center and a Public Transit Center.

NRCA-member Black Roofing Inc., Boulder, Colo. was selected to install all water proofing membrane assemblies and coatings for the $544 million project. The crew began work May, 2014.

On the 433,000-square-foot Westin hotel, Black Roofing’s work on the project included:

* Installation of a hot fluid-applied, fabric-reinforced American Hydrotech Monolithic Membrane 6125® assembly, including custom-tapered extruded polystyrene insulation and layered drainage mats.

* An expansion joint cover assembly with a fire barrier installed between the plaza and existing terminal.

* Installing 2,000 square feet of hot fluid-applied membrane assembly at the grade level planters at a covered entrance large enough for vehicles to pass through.

* Reflashing of more than 100 penetrations that were drilled to support the perimeter DIA 3pool drain when it was installed. This included custom-made stainless-steel counter-flashings and fabricating and installing a mile-long termination bar.

Black Roofing’s work on the 82,000-square-foot Public Transit Center included:

* Fabrication, installation and detailing of more than 250 copper sweep inserts before installing 47,000 square feet of American Hydrotech Monolithic Membrane 6125 on the concrete platform and transit’s main area.

* Application of more than 10,000 -square -feet of traffic coating at various mechanical rooms throughout the Public Transit Center and the Westin hotel.

Because DIA is in the middle of an open prairie, Black Roofing workers faced harsh, unblocked winds and cold temperatures throughout the construction process.

A project requirement also called for a 7/8- to 1 3/8 -inch thickness of sand below the concrete pavers covering the waterproofing assembly. Specified slopes had to be accomplished with tapered insulation, which proved to be challenging for workers installing insulation.

DIA 2After the first couple of weeks of installing the insulation and drain boards on top of the water-proofing membrane, workers realized the final tapered slope exceeded the slope by 3/8 of an inch per foot. As a result, Dan Zahtila, president of Black Roofing, spent six weeks on the job site making modifications.

In addition, the sand bed specification was so thin, it wasn’t possible to adjust the slope, and the sand and pavers would not hold down the drain board.

“We spent thousands of dollars and many sleepless nights trying to make an unworkable situation workable,” Zahtila says. “The precise requirement of the ¼ -inch -per -foot deck slope dominated the job for four months until we found a resolution.”

Sub-zero temperatures proved to be an additional challenge, and heat cables were laid out to keep the sand from freezing so it could be screed to accept the pavers. In many cases workers had to tear out the insulation and sand where the 2 percent slope requirement was not met.

Additionally, four plaza areas were designated as art areas and required Black Roofing workers to spread nearly 450 tons of 4- to 6-inch diameter cobble ballast that was hoisted to the plaza one bucket at a time by a crane positioned between two light wells 100 feet below.

Despite the challenges of the project during the project, after 25,000 man-hours, Black Roofing completed its work on the DIA South Terminal Redevelopment Program in time for the hotel to open April 22, 2016.

“This project put us on the map with the general contractor community as a roofing contracting company that can handle any waterproofing job regardless of size or difficulty,” says Tim Black, founder of Black Roofing.

For its outstanding efforts, Black Roofing received a 2017 Gold Circle Award in Outstanding Workmanship: Low-slope category and a Gold Circle Safety Award.

The project is featured in the May 2017 issue of Professional Roofing magazine. Visit–05-01-2017/4014.

Eberhard Roofing & Waterproofing Helps Design and Install Pomona College’s Studio Art Hall


Pomona College is a 140-acre campus located in Claremont, Calif. The school currently offers 48 majors and minors to 1,640 students.

In 2014, the college turned to NRCA -member Eberhard Roofing & Waterproofing, Van Nuys, Calif. to construct the roof system of its new 35,000-square-foot Studio Art Hall that was designed to interconnect studios and bring together disciplines ranging from sculpture and painting to digital arts and media.

pomona-2More than half the new building’s exterior was made of glass and consists of a free-flowing design to encourage interaction and collaboration in shared space, including a central courtyard.

The building’s striking canopy roof system combined design elements with challenging installation requirements. Eberhard Roofing & Waterproofing worked closely with the project’s architectural firm, wHY, Los Angeles, to devise a roof system that would meet the new art studio’s needs

The solution was a tan-colored Sarnafil 60-mil-thick feltback thermoplastic membrane adhered to Cell Crete lightweight insulated concrete, which saved Pomona College $150,000 and also increased the roof system’s wind-uplift rating from FM 1-90 to FM 1-240.

In January 2014, Eberhard Roofing & Waterproofing began installing Studio Art Hall’s roof system.

The canopy-shaped roof system design was achieved by pouring the lightweight insulating concrete into the desired shape on top of the existing concrete roof deck. A Sarnafil feltback G410 thermoplastic membrane then was adhered to the concrete.

In addition, Eberhard Roofing & Waterproofing installed a photovoltaic (PV) panel system over the thermoplastic roof membrane to allow for the installation of six skylights.

One of the most challenging parts of the project was incorporating fire sprinklers under the facility’s ceiling. Before the sprinklers were installed, a vapor retarder was placed over the concrete roof deck to ensure the light-weight concrete did not drip through the sprinkler holes in the roof deck.

In April 2014, Eberhard Roofing & Waterproofing completed the installation of Pomona College’s Studio Art Hall’s unique roof system.

Eberhard Roofing & Waterproofing received a 2016 Gold Circle Award honorable mention in the Innovative Solutions: New Construction category for its work on the Studio Art Hall.

Korellis Roofing helps build Chicago’s Chinatown public library

Chinatown Library 2 300dpi

Since 1873, the Chicago Public Library system has served Chicagoans with free, open places to gather, learn, connect and read.

On Aug. 29, 2015, the Chicago Public Library system opened a new, 16,000-square-foot, two-story, branch in the city’s Chinatown neighborhood. The feng shui-inspired structure was designed to harmonize with its surrounding environment and is partially covered with a living roof, installed by NRCA member Korellis Roofing Inc., Hammond, Ind.

Working on a roughly 8,400-square-foot roof with 3,900 square feet covered in vegetation posed significant challenges.

“This project was in the heart of the Chinatown neighborhood in Chicago, so staging and loading of materials presented significant logistical challenges,” says John Ziolkowski, vice president–roofing operations at Korellis Roofing.

In addition, Korellis Roofing used a Garlock Equipment Perimeter Clamp Guardrail system to provide workers with fall protection while installing the roof membrane.

Chinatown Green Roof In Progress

Workers assemble the vegetative roof system on the Chicago Public Library’s Chinatown Branch

After the PVC roof membrane was installed, workers used a permanently installed horizontal lifeline system that borders the vegetative roof area during installation and placement of the vegetative roof system.

After overcoming numerous logistical and fall-protection challenges, Korellis Roofing successfully completed its work on the Chicago Public Library’s Chinatown branch in July 2015 in time for its August 2015 grand opening.

“The most rewarding aspect of this job was this project was truly successful because of our workforce, workmanship and expertise with installing PVC membranes and vegetative roofs,” Ziolkowski says.

For demonstrating excellent workmanship on the Chicago Public Library’s Chinatown branch, Korellis Roofing was selected as a 2016 Gold Circle Awards finalist in the Outstanding Workmanship: Low-slope category.

For more details about Korellis Roofing’s work on the roof system of the Chicago Public Library’s Chinatown branch, visit–06-01-2016/3845.

Alumni Roofing Co. Replaces Roof System for Ohio-based Health Facility, Restores Local Landmark

DSC_0006-web-1040Avita Health System is a nonprofit organization providing care to patients in need of financial assistance in Ohio’s Crawford, Marion and Richland counties.

In 2013, Avita Health System purchased a 185,000-square-foot building at Richmond Mall in Mansfield, Ohio, to be renovated into a medical facility. The $50 million renovation took place in several phases beginning in 2014.

A tower built on the building in 1972 to provide a screen wall to an out of date HVAC unit had become a local landmark. Avita Health System wished to maintain the tower as the building’s focal point. To accomplish this, Avita Health System turned to NRCA -member Alumni Roofing Co., Lexington, Ohio, to come up with design options for preserving the tower.

Avita-(4)-web-1040After presenting several possibilities, Alumni Roofing proposed installing a TPO membrane with the Avita logo on the TPO membrane. The company created a temporary vinyl sign with the Avita Health System logo and hung it on the tower to demonstrate the logo’s size and placement on the tower. Avita Health System chose to go with Alumni Roofing’s recommendations.

Before beginning work on the new roof system, Alumni Roofing had to address the significant safety challenges of working on a structure 100 feet in the air during high winds.

Alumni Roofing used adjustable roof brackets with 2- by 6-foot planks.IMG_1417-web-1040

“Each installer had two ropes – on for the front lanyard harness and another rope to hold onto,” says Todd Lindeman, vice president of operations for Alumni Roofing.

In addition, Alumni Roofing installed a guardrail to prevent tools and debris from falling to the ground.

After extensive preparation, the TPO membrane with the Avita Health System logo was adhered to the tower. Once the roof system was complete, Avita Health System installed multicolored LED lights around the tower’s base to make it visible from nearly 1 mile away.

In December 2014, Alumni Roofing successfully completed its work on the Avita Health System tower.

“The most rewarding part of the job is knowing we played a key role in preserving a community landmark,” Lindeman says. “And we helped our customer develop a unique focal point to its new hospital.”

For demonstrating ingenuity on the project, Alumni Roofing received a 2016 Gold Circle Award honorable mention in the Innovative Solutions: Reroofing category.

For more details on Alumni Roofing’s work on Avita Health System’s roof system, visit–06-01-2016/3845.

NRCA Member United Materials Helps Construct the Science Pyramid at Denver Botanic Gardens

United Materials 2

Varying levels of low and steep slopes give the Science Pyramid at Denver Botanic Gardens a tectonic plate appearance.

Constructed in 2014, the Science Pyramid at Denver Botanic gardens showcases the garden’s scientific foundation and invites visitors to see the world of plants through a scientific lens. The exhibition uses interactive technology such as touchscreens, light, sound and video to teach participants about Colorado’s ecosystems, how plant scientists explore the world by studying plant organisms in depth and how backyards are connected to staff into the field across the state and throughout the world’s steppe regions.

The Science Pyramid’s exterior design consists of 4-foot-wide, hexagon-shaped concrete-composite panels based on bio-mimicry and meant to resemble honeycombs. The roof system was designed to enable rain and snow to flow underneath it rather than down it.

United Materials

United Materials workers apply a moisture barrier membrane to the pyramid’s plywood roof deck.

NRCA member United Materials, Denver was contracted to construct the Science Pyramid’s roof system. The company’s work on the project began in June 2014 and included:


  1. Adhering a DELTA-VENT SA moisture- and air-barrier membrane to the plywood roof deck
  2. Setting two layers of polyisocyanurate insulation in polyurethane
  3. Setting a layer of DensDeck in polyurethane
  4. Adhering a DELTA-FASSADE S ultraviolet-resistant, moisture-and air-barrier on the top membrane
  5. Installing 4-foot-wide hexagonal skylights and grates
  6. Installing 13 4-foot-wide hexagonal skylights and grates
  7. Adhering a DELTA-FASSADE membrane behind wooden walls to waterproof the interiors of maintenance and equipment rooms, including taping of all Z-girts, transitions and terminations
  8. Installing a drainage system for sump pumps to transport water into an adjacent pond

During the project’s most challenging phase, the architect and engineer measured the 4-foot hexagonal skylights. As a result, United Materials workers had to cut out, relocate, rework and reflash all 13 skylights. Given the varying degrees of each slope, it took patience and double-checking each mathematical commitment for check and balance.

Because of regular high-volume visitor tours and hours of the Denver Botanic Gardens, a fence was constructed around the job site to protect the public from the construction area. Access to the job site was limited from 9 a.m. to 5 p.m.

In addition to limited work hours, all material delivers to the job site needed to be brought in on carts. Working from varying slopes and different angles also presented a safety challenge for the United Materials crew. Workers were tied-off and anchored to a center pole and safely moved ropes through the Z-girts.

Despite the challenges of working with an unusual roof system design and reinstalling skylights, in September 2014, United Materials completed its work on budget. The atypical design challenged all workers beyond their usual comfort levels to creatively problem solve.

“The Science Pyramid at Denver Botanic Gardens was an excellent venue for tapping into the deeper creative talents of United Materials project leadership and crew,” says Craig Ducker, foreman for United Materials. Most important, the high-visibility accomplishment pleased the Denver Botanic Gardens staff and visitors. But for United Materials, it simply was a rewarding project and process.

“The most rewarding part of the project was being able to enhance the Denver Botanic Gardens that has been part of the city’s culture and landscape since 1051,” says Jim Kirkland, project manager for United Materials.

For its outstanding efforts, United Materials was honored with a 2016 NRCA Gold Circle Award which recognizes outstanding workmanship and contributions to the roofing industry, including unique roofing-related jobs, programs and services in the Innovative Solutions: New Construction category.  The company received the award during NRCA’s 129th Annual Convention and the 2016 International Roofing Expo® in February.

NRCA Member Midland Engineering Restores Roof System on 123 Year-Old Cathedral, Maintains Historical Accuracy

005Constructed in 1893, Birmingham, Ala.,’s the Cathedral of St. Paul’s Gothic Revival design incorporates intricate, multicolored slate patterns on the main roof.  It also includes several steeples, ornate copper cornices and dozens of unique architectural copper features commissioned specifically for the church more than a century ago.

In 1955, the church was extensively renovated and air conditioning was installed. In 1972, the church underwent structural repairs, and the sanctuary was remodeled. In 1922, exterior and interior ramps and doors were added to provide access for all to the church. Finally in 2013-14, the roof system was renovated by Midland Engineering Co. Inc., South Bend, Ind.DSCN0470

Following the Catholic archdiocese clear requirement that the new roof system be a historically accurate reproduction in materials, design and craftsmanship of the original roof system, Midland Engineering reproduced historically accurate slate patterns in multiple colors; six large slate crosses; dozens of copper finials and turrets; and more than 500 feet of copper cornices and radius gutters with matching straps.

As a result of thinning metal brought about by advanced age, every copper architectural and functional feature incorporated into the existing roof system had to be carefully removed and shipped 700 miles to Midland Engineering’s South Bend facility to be replicated in its metal shop.

More than 20,000 square feet of 16- and 20-ounce copper were used for custom-fabricating architectural elements and flashing. The off-site detailed copper fabrication work continued for the duration of the 11-month project while Midland Engineering’s on-site crew worked on the slate roof system. After removing the original slate roof and completing structural repairs, workers adhered Grace Ice & Water Shield to the deck and began to work on the slate roof.

Because of the noise inherent in roof construction, work schedules had to be planned around regular church services and rescheduled several times per month for funerals and other events.

In addition, Midland Engineering was tasked with upgrading the roof system to improve attic ventilation while maintaining the look of the Gothic Revival period.

After overcoming numerous scheduling and historical-accuracy challenges, Midland Engineering completed its work on The Cathedral of St. Paul in October 2014.

“The team’s work in piecing together such an intricate weave of slate and copper to restore our church’s beauty and keep it safe from water was such a marvel to behold,” says the Very Rev. Kevin Bazzel, VG, JCL, rector for The Cathedral of St. Paul.

DSCN0200Midland Engineering received a 2016 Gold Circle Award in the Outstanding Workmanship: Steep-slope category.

NRCA’s prestigious Gold Circle Award recognizes outstanding workmanship and contributions to the roofing industry, including unique roofing-related jobs, programs and services.