The Children's Hospital, Denver
The test of this ceiling revolved around aligning the "star". This was the point where wood, fiberglass and metal elements intersected across one integrated ceiling geometry. "It was extraordinarily successful — in the end," recalls Kip Storey, lead design architect for Zimmer Gunsul Frasca on Denver's new Children's Hospital.
"Challenges? Where to begin?" quips Wes Keesen of Acoustical Services, the installing acoustical subcontractor. Long time architectural rep Ken Rowland of Creative Alternative explains, "I've done many things in 30 years of specialty projects (e.g., the Denver Airport) but never one demanding so much complexity and so much coordination." Part-time project manager, coach, lobbyist, chief cheerleader and go-between, Rowland brought together 3 different manufacturers he represents: Accent (Adams-Campbell), 9Wood and Wall Technologies, to tackle the design challenges.
Denver's new $550 million pediatric hospital was designed to be filled with light, color, imagination and confidence. Explains ZGF's Storey, "We wanted the ceiling to firmly signal a public gathering space." A dynamic triangular lay-out was conceived, the geometry starting from the outside gardens and accented inside with bays marked off by metal light and diffuser troughs. "We needed the light coves to pull together the gardens and the interiors. We chose White Maple to make the ceiling light, optimistic — and economical. But there were a lot of hard surfaces acoustically. So we introduced the idea of alternating acoustical and wood panels."
"The specified companies said it couldn't be done," recalls Rowland with a twinkle. Rowland took up the challenge. Knocking on the doors of long time collaborator Bill Dilatush of H+L Architects, the project's architect of record, and Gary Constant of Phipps McCarthy, the General Contractor, Rowland proposed a mock-up in his Denver show room. Architect Storey: "When the GC proposed an alternative system, we were concerned. We're skeptical of substitutions because they often don't represent the features we've selected from the manufacturers in the specifications."
"I was concerned about the mock-up," recalls Dan Boustead, President of 9Wood. "We had to bring so much together in so short a time. It took us two weeks just to crack the secrets of the geometry. Then we had to agree on suspension approach, tolerances, and drawings across three different manufacturers." Tensions mounted as finishing touches were put on the 6 panel mock-up. With contractors and manufacturers gathered in the sales rep's show room they awaited the architect. When ZGF's Storey walked through the door he stopped. "My God, somebody can build what we designed!" he exclaimed.
It was only the beginning of many mock-ups. "I would call it a nightmare of engineering on top, to create a simple design from below," stresses Bob Cadman of Accent. The team looked to torsion springs as the best approach to suspension; simple in concept, difficult in execution. Trouble fabricating to the required fine tolerances is a universal memory. "We went through 3 or 4 approaches to find a way to make fiberglass work with the unforgiving tolerances we needed," says Cadman. 9Wood's Jayson Hayes, comments: "We had to develop a new kind of panel jig, a new spring rail, and a new alignment tool to get the wood to hit the tolerances."
Echoing the theme of tight tolerances, installer Wes Keesen recalls, "Running the system and keeping the tolerances uniform was our biggest challenge." Acoustical Services laid out the ceiling with lasers off survey scribes on the floor. The triangle geometry required Accent not only to punch the T-Grid flange slots accurately, but to cut the grid at the correct angles and correct indexes--otherwise the fiberglass panels and the wood panels would not fit together with the grid. 9Wood fabricated a Jig Table for the Acoustical Services crew to assemble the grid on-site. "This go/no-go jig made a huge difference," emphasizes Keesen.
Tight physical tolerances were matched by the tight collaborative tolerances needed to bring different manufacturer's together to create one, unified and integrated ceiling. "This would have been tough for one manufacturer, let alone three," observes Keesen. Collaborative mock-ups prior to shop drawings are rare in construction, which tends towards mock-ups after shop drawings. "I would recommend this process of early mock-ups, review and refinement to any owner," comments ZGF's Storey. "Getting everyone to work together takes some trust building; construction isn't used to working this way." Comments Jayson Hayes of 9Wood, "A lot of people from a lot of companies were involved in the R&D process to pull off the suspension system and to make the reveals align and work." "Only an independent rep like Ken [Rowland] could pull it together. He was the hub. He kept it together," recalls a team member.
There were other hurdles for the team. "We wanted minimum penetrations in the ceilings to maintain the strong design — so we hid a lot of mechanics in the fixture troughs," explains Storey. Says Accent's Cadman, "Normally, torsion springs are placed close to the panel ends. But to make the troughs work, we needed to bring them back. This threw off our reveal alignment tolerances." Stresses Creative Alternative's Rowland, "We had to deal with light leaks, fire codes, air make-up, smoke control, electrical, sprinklers up in the troughs -- all the while keeping our 1/4" reveals dead-on." Continues Cadman, "This large cantilever was a real problem. So we developed a special carrier to make it work. Our engineering guys did a crackerjack job!"
One final hurdle remained: the building's acclimatization. The Children's Hospital was acutely sensitive to cleanliness. No HVAC was activated on a floor until everything on that floor was buttoned up. This policy meant soaring temperatures and plummeting humidity — and panels that weren't fitting after installation. "They duct taped everything shut," recalls Creative's Rowland. "I've never seen that before." The team began monitoring the environment to arm themselves with data for the GC's consumption. "Sometimes a rep has to do it all," laughs Rowland, who was awarded a special Blue Ribbon Monitoring Prize. As each floor's HVAC was turned on the panels returned to normal, the reveals closed up and everyone breathed a sigh of relief. It worked just like the humidity table says it works.