Photo courtesy of CRS of Monroe Inc., Monroe, N.C.
Photo courtesy of CRS of Monroe Inc., Monroe, N.C.
Photo courtesy of CRS of Monroe Inc., Monroe, N.C.
Photo courtesy of CRS of Monroe Inc., Monroe, N.C.
Carolinas HealthCare System, the largest health care system in the Carolinas, operates 23 hospitals, eight in the Charlotte, N.C., area alone. In 2004, the network decided to build a new children's hospital at the campus of Carolinas Medical Center in Charlotte, as well as expand the medical center's intensive care unit (ICU) tower.
"We were asked to bid on the projects by Carolinas HealthCare System, who is a repeat customer," says Scott Baxter, vice president of CRS of Monroe Inc., Monroe, N.C.
CRS of Monroe won the bid and began the Carolinas Medical Center project in late 2004.
Demanding work
Work on Carolinas Medical Center got off to a rocky start.
"The project was delayed from the start because the original general contractor was fired before project construction even started," Baxter says.
When work did begin, CRS of Monroe was asked to do several things.
"One portion of the project was to expand the ICU tower by adding several stories to the existing tower," Baxter says. "We tore off 25,000 square feet of the existing roof system—a built-up roof system over tapered polyisocyanurate roof insulation. Debris was removed using a skip pan by a tower crane more than 200 feet tall.
"The roof system had to be torn off at this point or it would have been encapsulated into the vertical expansion and, subsequently, would have needed to be removed via freight elevators," Baxter continues. "The temporary roof system currently remains in place but will be removed later this year when the building's eighth floor—formerly the roof—is enclosed and converted to interior space."
After tearing off the existing roof system, CRS of Monroe primed the existing concrete deck and installed a temporary roof system on the concrete deck—an SBS polymer-modified bitumen sheet set in cold adhesive with the seams heat-welded to allow construction traffic over the area. A temporary EPDM membrane was installed over exposed wall tops and roof edges.
After additional stories were added to the building, CRS of Monroe installed a Tremco Inc. cold-applied built-up roof (BUR) system on the ICU tower.
"The new deck is structural concrete, and a cellular lightweight concrete system was poured to provide R-value and slope to drain," Baxter says. "The BUR system was installed over a venting base sheet, which was mechanically attached to the lightweight concrete."
CRS of Monroe subsequently also installed Tremco cold-applied BUR systems on the new Levine Children's Hospital's multiple roof areas.
"The new building has 14 roof areas, including two rooftop play areas with small green roofs/planters," Baxter says. "Performance Derbigum APP polymer-modified bitumen membranes were installed in Permastic® modified cold adhesive on the rooftop play areas and planters. The APP membrane was applied directly to the concrete deck in cold adhesive with welded seams, and extruded polystyrene insulation was installed over the APP membrane before installation of the traffic surface."
Additionally, recycled EPDM tiles were installed on the rooftop play areas to cushion any falls.
"The recycled EPDM tiles, which interlock on all four sides, were placed over a substrate that includes a proprietary stainless-steel support track adhered to the APP membrane," Baxter says. "We mechanically attached fiberglass grate to the stainless-steel track and then installed the interlocking tiles."
The play areas subsequently were enclosed by precast concrete screen walls and plexiglass screen walls.
Overcoming obstacles
CRS of Monroe faced significant challenges during the project.
Baxter says: "Space and access to the site were extremely limited, which meant materials delivered to the job site had to be lifted by crane to the roof the same day. Setup areas were limited in size and came at a premium. Our roof systems became storage sites, and even though the roofs were protected with insulation and plywood in many areas, damage to the roofs occurred and had to be repaired.
"Additionally, the exterior walls of Levine Children's Hospital were designed on four different radii," Baxter continues. "All construction components were a challenge at these locations and where the radius wall and adjacent tower expansion abutted. We installed 4-foot sections of curved coping."
Another obstacle presented to CRS of Monroe: There was a mere 4-inch space for waterproofing between a 36-foot-long skylight and precast panel wall.
"We handled this by designing a stainless-steel gutter lined with EPDM between the skylight curb and precast concrete screen wall and installing it from a swing-scaffold," Baxter says.
Safety sensitive
Safety was an important consideration during this project.
"Safety was of paramount concern—the hospital system definitely did not want someone injured on a hospital project," Baxter says.
The project's general contractor, Birmingham, Ala.-based Robins & Morton, installed temporary guardrails with steel cable midrails and toprails in many places. Additionally, CRS of Monroe used Protective Roofing Products Ltd. PR-600 fall-protection devices.
"Also, because work was performed over sensitive areas of the existing hospital, such as the neonatal ICU, fume/odor containment 'rooms' were constructed to vent these areas," Baxter says.
A great challenge
CRS of Monroe completed work on the ICU tower and Levine Children's Hospital in late 2007. And in spite of the numerous obstacles CRS of Monroe encountered during its work, the project proved to be rewarding.
Baxter says: "The entire design of the Levine Children's Hospital is unique—especially the rooftop play areas.
"Designing many of the components and methods for construction of those components was great—a real mental and physical challenge," Baxter continues. "The architect and general contractor were amenable to our suggestions for design and installation of unusual conditions, and the cooperation we got from them made the job a little bit easier."
Ashley St. John is Professional Roofing's associate editor.
Project name: Levine Children's Hospital and the intensive care unit tower at Carolinas Medical Center
Project location: Charlotte, N.C.
Project duration: Summer 2004-fall 2007
Roof system type: cold-process built-up; APP polymer-modified bitumen membrane; and recycled EPDM tile traffic surface
Roofing contractor: CRS of Monroe Inc., Monroe, N.C.
Roofing manufacturer: Performance Roof Systems Inc., Kansas City, Mo., and Tremco Inc., Beachwood, Ohio.
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