Dickies Arena Plaza Deck Extends the Experience

The Dickies Arena plaza deck hosts a variety of outdoor events and protects visitors and livestock in the exhibit space below. Photos: Trail Drive Management Corp.

Commemorative events to celebrate the grand opening of Dickies Arena in fall 2019 ranged from a ribbon cutting party to Monster Truck competitions, and performances by Twenty One Pilots, the Black Keys and the Harlem Globetrotters. The arena is home to the Fort Worth Stock Show and Rodeo and other sporting events.

Not all the action takes place under the domed roof, however. The Dickies Arena plaza deck provides not only breathtaking views of the Fort Worth skyline, but offers a high level of functionality, strength and performance to protect visitors and livestock.

According to Bill Shaw, operations manager at Dickies Arena, the plaza is designed to serve as an extension of the rodeo, enabling visitors to watch the livestock from above. Ten-to-12-foot windows built into the plaza deck provide a view of the 100,000 square foot warm-up area where animals work with their handlers before barrel racing and other rodeo events. A roadhouse tent hosts musicians for plaza deck performances held following the rodeo. And instead of a conventional courtyard, Dickies Arena boasts a “cork yard” wine and food space.

Functionality Fuses With Performance

From lush green spaces that provide a scenic vantage point for taking in the iconic Fort Worth skyline and views of nearby barns and stables to fire lanes for emergency vehicles and concert equipment deliveries, Dickies Arena requires a plaza deck that can deliver outstanding strength. And in Fort Worth’s unpredictable weather, it must also successfully manage storm water runoff. The insulation used in the roof — Owens Corning Foamular extruded polystyrene (XPS) — is key to delivering compressive strength and storm water management performance. But the team specifying insulation for this unique landmark encountered some unusual challenges.

Exhibit areas underneath the plaza deck can be configured to house livestock. During rodeos, a warm-up area for horses is set up underneath the pavilion.

With a plaza deck encircling the main arena of about 140,000 feet, the size, scale and slope of the Dickies Arena plaza deck all presented challenges for the insulation team, beginning with the estimating process. The plaza’s design required a blend of tapered, flat filler, and reverse tapered installation.

Each phase was broken into three layers. The reverse taper layer brings the slope of the roof back to a flat slope. The flat fill section raises the height of the roof without adding the weight that concrete would have contributed to the plaza. A traditionally sloped area above the slab and pavers directs water back to the drainage assemblies located in the top layer of the roof. These layers had to be carefully calculated for many sections around the jobsite that changed in priority as construction surged ahead of schedule.

All the calculations required an experienced team who could coordinate and collaborate in real time. Sunbelt Building Services LLC was the insulation distributor on-site and team members’ experience in the roofing industry proved to be an invaluable asset. As Sunbelt prepared the drawings, Owens Corning calculated the insulation estimates by computer and by hand to ensure accuracy, piece by piece, and then Sunbelt reviewed them again. “You’ll never get the correct material count if you don’t know how the roof is sloping, where the drains are located and how to interpret the structural architectural drawings,” says Darrell Evans, project manager at Sunbelt Services. The result of the estimating process showed the collaboration and teamwork were successful. The estimated insulation for one of the first phases was within two pieces of the material used on the jobsite.

Managing Storm Water

Based on the “sandwich” of the roof design, Dickies Arena required two sets of drains sloping in different directions, according to Eric Nelson, AIA, RID, CCCA, and vice president at HKS, the architect of record for Dickies Arena.

The plaza deck had to be designed to withstand heavy stresses including emergency vehicles and equipment deliveries. Owens Corning Foamular extruded polystyrene insulation was specified for its compressive strength and storm water management performance.

The structure has one set of drains at the lowest level, where TREMproof 6100, a waterproofing membrane from Tremco, was hot-mopped into place over the concrete slab. On top of the waterproofing layer is the insulation and filter fabric, as well as the sand bed, Hanover pavers, and planters with trees. Slot drains at the top level collect surface water, and the drains at the lower level collect any water that works its way through that system. Extensive modeling was helpful in determining not only the placement of drains but precisely how much insulation should be used — and its depth and location — in various parts of the plaza deck.

Given all the activity taking place on the plaza roof, material weight was a huge consideration when selecting the roofing insulation. Emergency vehicles must be able to navigate the fire lanes that encircle the deck. Semi-truck trailers need to unload concert equipment and staging. From a building material perspective, the plaza deck supports 5 inches of concrete in addition to the weight of the insulation, with reverse tapering depths varying from 3 to 5 inches. In some areas, the plaza deck’s insulation is 12 to 13 inches deep.

While the project was originally specified to require 100-psi insulation, the team evaluated the Dickies Arena design structure and determined its design would allow weight to be distributed in a way that could be effectively managed by a 60-psi insulation. This exercise in value engineering revealed the lighter compressive strength XPS could deliver required strength and offer better economics. The plaza can support weight loads of 25,000 pounds.

Logistics Require a Team Effort

With the estimating complete and materials specified, supply chain management became an area of focus. Owens Corning worked with its manufacturing plants across the nation to coordinate logistics involved with production of XPS product and delivery to the jobsite.

A best practice on any construction project is to ensure products are not left unprotected and exposed to the elements, so communication and jobsite staging were coordinated between Owens Corning, Sunbelt and various contractors on the job. As XPS continues to expand slightly after manufacturing, the insulation was “aged” for 30 days after it came off the line. Owens Corning production plant teams, product managers and sales managers worked with a dedicated purchase order processor and a team of 20 to manage the plaza deck insulation project through to completion.

This detail from architect of record HKS Inc. shows the “sandwich” design of the plaza roof, which required slot drains at the surface and drains in the underlying slab. Image: HKS Inc.

On the jobsite, tapered pieces were sent up the slope and cut into specific rectangular sizes. Easily cut with a knife, structurally sound XPS isn’t prone to breaking into messy pieces and avoids random materials blowing away from the construction site. Given the sunny and windy climate in Fort Worth, the contractor kept exposed materials protected from sunlight and glued loose pieces together with a product that would not harm the insulation. Ordering the right amount of the right products at the right time was essential when considering up to 700 people were working on the project during peak construction periods.

The effect of the plaza deck gracing Dickies Arena can be summarized by modifying a common statement about Texas: “Everything is bigger and better in Texas.”

About the author: Tiffany Coppock, AIA, NCARB, CSI, CDT, LEED AP, ASTM, RCI, EDAC is the Commercial Building Systems Specialist at Owens Corning where she provides leadership in building science, system development, testing, and documentation.  

TEAM

Architect of Record: HKS Inc., Dallas, Texas, www.hksinc.com

Plaza Deck Installer: Sunbelt Building Services LLC, Dallas, Texas, www.sunbeltllc.com

MATERIALS

Waterproofing Membrane: TREMproof 6100, Tremco, www.tremcosealants.com

Insulation: Foamular 600, Owens Corning, www.owenscorning.com

Brick Pavers: Hanover, www.hanoverpavers.com

Douglas A. Munro Coast Guard Headquarters Boasts One of World’s Largest Green Roofs

The Douglas A. Munro Coast Guard Headquarters Building in Washington, D.C., has more than 550,000 square feet of green roof space. Photos: Owens Corning

Like a 550,000-square-foot sponge, the vegetative roof assembly (VRA) atop the Douglas A. Munro Coast Guard Headquarters Building in Washington, D.C., absorbs rainfall while managing its release into the city’s sewer system. Green roofs are a storm water management “best practice” in the nation’s capital, which boasts more than 3.2 million square feet of green roof space.

Gordon Contractors installed the green roof on the 11-level, 1.2-million-square-foot headquarters, which is also home to several independent field commands including the National Pollution Fund Center and Marine Safety Center. Key performance objectives included complying with D.C.’s stringent storm water regulations, as well as federal Environmental Protection Agency (EPA) rules requiring 95 percent of storm water to be collected onsite.

Beyond complying with local and federal storm water mandates, the project team creating the vegetative roof sought to create a rooftop habitat that supports biodiversity and helps birds and other wildlife thrive. The result of a careful and collaborative approach to moisture management is a high-performing roof that ultimately received LEED Gold certification from the U.S. Green Building Council. Working as a system, the roof’s components help reduce rainwater runoff while helping to reduce pollutant loads and protect natural resources such as the nearby Chesapeake Bay.

Numerous Challenges

As every roofer knows, no two projects are alike. The location of the Douglas A. Munro Coast Guard Headquarters on hilly terrain provided plenty of natural obstacles, including nine of the eleven levels being built into a hillside. The site

Gordon Contractors installed the green roof on the 11-level headquarters. Performance objectives included complying with D.C.’s stringent storm water regulations, as well as federal EPA rules requiring 95 percent of storm water to be collected onsite. Photos: Owens Corning

features a series of stair-stepped green roof terraces that help gradually move water from higher to lower levels and eventually into a pond through elevation changes of 120 feet. According to Steve Gordon, president of Preservation & Protection Systems Inc. (PPSI), the company providing design and installation support with the Owens Corning FOAMULAR extruded polystyrene insulation and Henry 790-11 Hot Rubberized Asphalt used in the VRA, the stair-step design required a complex approach to the roof’s varied elevations. To meet this challenge a complex network of expansion joints by EMSEAL tied together multiple air barriers within the system. Another challenge was the magnitude of the project, spanning more than a half-million feet across multiple levels and 176 acres. Timing was critical, as plants and vegetation required quick delivery and transplanting into their new environment, particularly during D.C.’s sweltering summers. These living materials couldn’t simply be covered with a tarp until better conditions prevailed, but had to be quickly transported, installed and irrigated.

The Douglas A. Munro Coast Guard Headquarters serves 4,000 occupants, so comfort and energy efficiency were important concerns. From the outset of the project, the integrated roofing team was tasked with designing a vegetative roof assembly that would help decrease the building’s heating and cooling energy usage, lower long-term maintenance costs and extend the life of the roof.

A Solution to Achieve Performance Goals

The project team selected a Protected Roof Membrane Assembly (PRMA) to deliver the water management required to meet storm water mandates, as well as deliver energy efficiency through R-value performance and strength to support vegetation requirements. The PRMA places the insulation layer above the waterproofing membrane, a reversal of traditional roof systems. PPSI recommended Owens Corning FOAMULAR 404 and 604 extruded polystyrene (XPS) insulations for use in the PRMA. The water resistance and compressive strength of the XPS insulation provided the integrity needed for long-term roof performance and helped the Douglas A. Munro Coast Guard Headquarters Building ultimately achieve LEED Gold certification.

The Douglas A. Munro Coast Guard Headquarters was built on hilly terrain, and nine of the eleven levels were built into a hillside. The stair-stepped green roof terraces help gradually move water from higher to lower levels and eventually into a pond. Photos: Owens Corning

Given the sheer size of the project, it was inevitable that the roofing team would encounter several scenarios requiring strategic problem-solving throughout the installation. For example, the team adjustedthe engineered soil specification to reduce the loads within the structural tolerances for the roof structure and carefully addressed a range of pH, moisture, organic matter and nutrient levels to support the variety of plants. Not only did such careful attention deliver strength performance, it’s also achieved the objective of attracting wildlife. The terraced landscape has welcomed not only birds and butterflies, but the occasional deer wandering onto a rooftop.

Evaluating Results

Since its completion, the VRA at the Douglas A. Munro Coast Guard Headquarters has attracted widespread attention from landscaping groups, engineering firms and organizations interested in sustainability. These groups are interested not just in the building’s unique design but in its resilience and performance. Steve Gordon of PPSI says the resilience of the headquarters’ roof is reflected in its record of no leaks. “We’ve had no leaks,” Gordon says. “The reason we use hot fluid applied waterproofing on green roofs is because we want to avoid any leaks in the building. At the end of the day, the biggest liability in a roof is water.”

After successfully navigating a range of challenges and opportunities, the U.S. Coast Guard Headquarters’ VRA epitomizes the convergence of aesthetics and performance and is recognizedas one of the largest green roofs in the world.According to the Landscape Performance Foundation, the headquarters’ vegetative roof retains up to 424,000 gallons of rainwater.

In a small way, the performance reflects the integrity of a hero an Act of Congress honored when naming the headquarters, according to Captain Will Smith, Commanding Officer U.S. Coast Guard Base NCR. Captain Smith noted, “The Coast Guard’s only Medal of Honor recipient, Douglas Munro earned the award for his selfless sacrifice as a landing craft pilot at Guadalcanal while evacuating marines from a beachhead under heavy fire from enemy forces.”

TEAM

Architect: WDG, Washington, D.C., www.wdgarch.com
General Contractor: Clark Construction Group, Bethesda, Maryland, www.clarkconstruction.com
Roofing Contractor: Gordon Contractors, Capitol Heights, Maryland, www.gordoncontractors.com
Independent Rep Agency: Preservation & Protection Systems Inc. (PPSI), Laurel, Maryland, www.ppsimd.com

MATERIALS

Insulation: FOAMULAR 404 and 604 extruded polystyrene, Owens Corning, www.owenscorning.com
Waterproofing Membrane: 790-11 Hot Rubberized Asphalt, Henry Company, https://us.henry.com
Expansion Joints: EMSEAL, www.emseal.com
Pavers: Hanover Architectural Products, www.hanoverpavers.com
Sedum Mats: Sempergreen, www.sempergreen.com