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.

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