Church Conference Center Opts for Rooftop Meadows
For decades, one of the challenges the church had was limited seating for General Conference attendees every April and October in the Tabernacle. Built in 1867, the Tabernacle, home of the Mormon Tabernacle Choir and located just west of the Salt Lake Temple, held 6,000. Church leaders needed not only a larger building, but also one with more technical capacity, including the ability to immediately translate proceedings into a host of different languages for television and radio broadcasting to its more than 11 million members worldwide.
The new Conference Center is on the block north of the temple, at the heart of downtown Salt Lake City. Two other church-owned structures, including the Desert Gymnasium, were removed, along with 450,000 cubic yards of earth. Just as the Tabernacle was known for its fine acoustics, church leaders also requested that the Conference Center be a high-quality structure. Rooftop gardens are one of its unique features. Other building highlights include four levels of underground parking, an auditorium that seats 21,000, a little theater seating 900, three levels of lobby access area with 13 passenger elevators, 12 escalators, and three service and stage elevators. More than 65 subcontractors and large suppliers were involved.
Utah Tile & Roofing Inc. has a staff of 70 and averages $10 million a year in projects. Past major projects included the 200,000-square-foot Marriott Library at the University of Utah. Paul Seppi, president of Utah Tile & Roofing, notes that the Conference Center was a fast track project. “The roof includes planters for landscaping and trees. Scheduling the work was difficult because there were lots of other tradesmen working over our finished product continually. Weather conditions also were a challenge.”
Seppi explains roofing is the wrong term. “It was a waterproofing project, and the contract had us start with the footings and waterproof vertical surfaces, as well as the roof itself. The total contract involved over 600,000 square feet of waterproofing, including walls reaching 115 feet.” Utah Tile & Roofing joined the project November 1997 and completed its work in November 2000, the month after dedication. “At the highest point, from April 1999 to April 2000, we had 60 people on the project.”
He then emphasizes, “Really, you can hardly tell we were on the project because all of our applied products are buried by soil, landscaping or paver walkways. The uniqueness of this project is the live water in fountains, runnels, and pools that add beauty and aesthetics. Our major concern was having live standing water on the roof at all times. Our onsite superintendent Amador Arevalo made sure everything was done perfectly. He’s our waterproofing expert and we keep him specializing in doing nothing but waterproofing with our projects.” Another plus is with all the roofing membrane covered, ultraviolet rays cannot degrade the product, thus minimizing anticipated maintenance as the years unroll.
Seppi credits Harvey Wright, manager of construction, for the smooth flow of work, despite the number of workers on the building at the same time. Wright notes there were as many as 1,050 people working two shifts. He adds that the contractor, Legacy Constructors, is a joint venture comprised of the three largest general contractors in Utah: Layton Construction, Okland Construction and Jacobsen Construction. “By going together, the three companies were able to supply as many as 400 workers at a time, both union and non-union.” Wright is senior vice president for Jacobsen Construction and has been in construction for 54 years.
Wright emphasizes that the fast-paced project was completed by working two shifts, 10 hours a day, six days a week. Appropriately, there was no Sunday work. Still, it took 4.5 million man-hours to complete the building.
Weather ChallengesAlthough the region is relatively dry, snowstorms can be a challenge. A typical storm is eight or more inches, and a couple dozen storms per winter is not unusual. While this amount of snowfall is a plus that helped the International Olympics committee decide to base next year’s winter games in Salt Lake City, all snow removal on the roof is done by hand.
Seppi notes, “We did our best to create mini-environments, working to dry the roof out quickly. Tenting and artificial heating with portable propane Salamanders helped. We purchased six and used them all until they were of no use anymore. I don’t recall us shutting down more than 2 to 3 days. We were able to work down to 10 degrees in typical Utah winter weather, storms and all.”
Seppi frankly adds, “Without Harvey Wright that building wouldn’t have been water tight. He was right up to speed all the time everywhere we were working. He made sure other people weren’t affecting or damaging our waterproofing. He really protected us. He made sure each trade understood if they damaged the membrane, they were responsible for it.”
When asked about onsite conflicts, a hazard with a fast-track project with numerous workers, each focusing on his company’s tasks, Wright replied, “We set a standard of cooperation on the project. Workers knew that we expected cooperation, and we kept those standards in front of people so there was no doubt in their minds.”
Another aid was weekly meetings with all the subcontractors, which allowed Seppi and the others to explain to each other their work plans for the next two to three weeks. Wright adds, “This helped all the companies work together, so the work could flow relatively smoothly, which is essential for a fast track project.”
There were as many as 11 different cranes on the project, with two tower cranes kept fully employed during both shifts. This allowed Utah Tile & Roofing, as well as all the other trades, to have their products onsite in a timely fashion. Any construction debris was removed quickly so all trades had access to their work areas. Wright estimates this strategy saved about two years in the construction schedule.
Seppi reports when they weren’t applying the waterproofing membrane, crews were busy working where they could. “I’ve been actively roofing for 35 years. The value of this particular project comes in being able to sit back and recognize the success it is and always will be, and the extremely difficult situation because so many trades were working together to complete the building quickly.”
An unexpected challenge, though, was a tornado that struck on August 11, 1999, when there were 1,000 workers on the site. Wright explains, “It touched down 10 blocks away to the southwest, came directly over the Conference Center and traveled northeast to the State Capitol. We had minimum damage to the structure. We lost a lot of Styrofoam from the roof and one tower crane collapsed onto the roof.”
Seppi comments, “We didn’t sustain a whole lot of damage, other than that crane and some scaffolding. It happened in a 20-minute period of time, then we had about a week’s cleanup.” One worker, struck by a piece of Styrofoam, sustained a broken shoulder, but was the only lost-time accident related to the storm. Three others reported minor injuries, but were treated and able to return to work immediately.
Safety SuccessSeppi adds that despite having up to six crews on the roof at a time, with four to 10 per crew, his workers had just one lost-time accident. “We had a full-time safety representative on the job, and so did Legacy Constructors. We held weekly safety meetings, and our people are trained in safety here at our shop. We also conduct and inspect our own projects for safety compliance.” This has yielded several safety awards for Utah Tile & Roofing, including CAN Safety Achievement Award and AGC Achievement of Safety Excellence, as well as a Workman’s Comp Fund modification rate of 0.48.
He notes the one accident involved a burn, and the employee missed a week’s work. “The material we were applying is much like asphalt, and is heated in a kettle. He was loading the kettle without a face shield and material splashed on him.” Seppi points out the irony of the accident, “The worker had his face shield sitting right there, but he didn’t use it.”
Technology InvolvedThe Conference Center roofing contractor then explains the system employed in roofing this building. He reports that Utah Tile & Roofing’s task included installing the Hydrotech Garden Roof™ assembly in the landscaped areas, as well as using the firm’s MM6125 waterproofing material on the remaining 100,000 square feet of roof area adjacent to the meadow and to the below-grade vertical walls.
“The surface is concrete, as with the whole building. In different areas we used different finishing product. In the paver walkway areas we used quarter-inch Permaboard, topped with a drainage mat. In the landscape areas we also had root barriers and water retention mats over reinforced hot-applied rubber.”
Wright notes, “A challenge was to keep the soil load down, so we applied Utelite soil in the meadow areas. Utelite has just 2/3 the weight of soil, and its depth varies from 6 inches in the grassy areas to 3 to 4 feet for the pines and aspens, some of which are in 6-foot-deep planters. We also have a complete irrigation system over the entire roof.”
He adds that a full-time inspector on the roofing during building helped. “Vigilance is the key to success. We had thousands of stone anchors to penetrate the membrane, so we water tested all the horizontal area.”
Seppi adds that there were few roofing problems discovered after completion. “One of the fountains leaked onto the plaza deck. Again Harvey got involved, removed the stone, and we extended the waterproofing. That took a four-man crew four days, but it was regarded as an unforeseen problem, so the repair was paid for by the owner. It was not a question of our workmanship.”
The building, first utilized for the April 2000 General Conference of The Church of Jesus Christ of Latter-day Saints, is a source of satisfaction in a job well done for Utah Tile & Roofing. All General Conference proceedings are televised throughout the world to members of the church. Besides focusing on the proceedings inside the building, TV camera crews also use occasional shots of the building exterior and roof. Utah Tile & Roofing is understandably proud of its work on this unique facility.
Side Bar: The SystemThe over 70,000-square foot rooftop meadow above the Conference Center is among its most distinctive features. In addition to creating an ecosystem on the roof, the meadow uses innovative “green” technology — the American Hydrotech Garden Roof® Assembly installed by Utah Tile & Roofing and Redd Roofing.
The Garden Roof begins with Hydrotech’s Monolithic Membrane 6125® waterproofing, which also covers the more than 100,000 square feet of below-grade vertical walls.
In the meadow area, MM6125 was applied directly to the deck, forming a seamless waterproof layer. Next, a root barrier was embedded into the hot material, and its seams torch sealed to provide an impenetrable barrier against aggressive root growth. To maximize water migration, Hydrodrain 300, a drainage composite with a flow rate of 7 gallons per minute per square foot, was installed at two layers – above the root barrier and immediately below the soil. Sandwiched between the Hydrodrain was Floradrain 40, a water drainage/retention component made of 100-percent-recycled polyethylene. With a flow rate of 513 gallons per minute per square foot, Floradrain offered efficient drainage at a fraction of the weight of pea gravel.
Along with the Mashantucket Pequot Museum & Research Center roof, Mashantuket, Conn., the Conference Center meadow is one of the largest garden roofs in the United States.