After Years of Roof Leaks, a Laboratory That Produces Theatrical Equipment and Software Undergoes a Complex Reroofing
Founded in 1910, Rosco Laboratories is a multi-national producer of equipment, software and products for the theatrical, film, and television industries and architectural environment. As with every aging flat roofing system, water leakage was becoming a recurring problem at Rosco’s Stamford, Conn., facility. The severity of the leakage was further exacerbated by the lack of roof drainage (only two roof drains serviced the entire building) and poor deck slope conditions (less than 1/16 inch per foot).
Rosco representatives employed traditional methods to control and/or collect the moisture within the building by use of several water diverters. This technique was effective but Rosco representatives soon recognized this was not a viable long term solution as the physical integrity of the roof structure (deck) became a principal concern to the safety of the building occupants.
The Fisher Group LLC, an Oxford, Conn.-based building envelope consulting firm was retained by Rosco in March 2009 to survey the existing site conditions and determine the need for roofing replacement. The existing roofing construction, which consisted of a conventional two-ply, smooth-surfaced BUR with aluminized coating, exhibited numerous deficiencies (most notably severe alligatoring) and was deemed unserviceable. Construction documents, including drawings and specifications and a project phasing plan were developed by Fisher Group to address the planned roof replacement.
Bid proposals were solicited from prequalified contractors in June 2010, and F.J. Dahill Co. Inc., New Haven, Conn., was awarded the contract on the basis of lowest bid.
The building basically consists of a 1-story steel-framed structure constructed in the 1970s. It is a simple “box”-style configuration, which is conducive to manufacturing.
In conjunction with design services, destructive test cuts were made by Fisher Group in several roof sections as necessary to verify the existing roofing composition, insulation substrate, moisture entrapment, and substrate/deck construction. A total of four distinct “layers” of roofing were encountered at each test cut. The existing roofing construction consisted of alternating layers of smooth- and gravel-surfaced, multi-ply felt and bitumen built-up roofing. The bitumen contained throughout the construction was fortunately asphalt-based. Succeeding layers of roofing were spot mopped or fully mopped to the preceding layer (system). The combined weight of the roofing construction was estimated to be upwards of 20 to 22 pounds per square foot when considering the moisture content. This is excessive weight.
It is interesting to note that a minimal amount of roof insulation was present in the existing construction. Insulation was limited to a single layer of 1/2-inch-thick fiberboard. Additional insulation would need to be provided as part of the replacement roofing construction to increase the roof’s thermal performance and comply with the prescriptive requirements of the Connecticut State Energy Conservation Construction Code.
The structural substrate, or decking, is conventional in nature, comprised of poured gypsum roof decking. The roof decking incorporates 1/2-inch gypsum formboard loose laid between steel bulb-tee supports spaced about 32 inches on-center. The poured gypsum roof decking in this instance was utilized as the structural substrate and for insulating purposes. Poured gypsum roof decking has a minimal insulating value of perhaps R-2 to R-3, which is obviously considered to be minimal by present standards.
A representative number of bulk material samples were obtained by Fisher Group from the existing roofing construction as necessary to determine the material composition. The sampling included field membrane roofing plies, coatings and cements, and associated roof penetration and perimeter flashings. Laboratory analysis revealed that the second, third and, in some instances, fourth roofing “layers” (field membrane plies) contained varying amounts—5 to 10 percent—of asbestos (chrysotile) which would necessitate full abatement of the roofing construction.
PHOTOS: The Fisher Group LLC
Hilton Garden Inn, Cleveland
Because of the area’s harsh winter climate, the hotel’s reroofing project required a redundant roofing system that would be strong and durable. The SOPREMA system chosen is typically used in climates like this for that reason.
Although the selection of this particular roofing system was easy, the installation presented a few challenges. The hotel’s roof includes a cell tower, containing a telecommunication terminal for all of Ohio. The installers had to be careful to avoid interference with the terminal when removing the original roof, as well as applying the new system. In addition, the mortar in some of the walls of the penthouse was deteriorating. The installation team had to flash in the ALSAN RS liquid system to keep water from penetrating and getting into the new roof system.
When the reroofing project began, installers first needed to remove the old coal-tar roof from the structural deck of the concrete building. Next, the deck was primed using Elastocol 500 and then a SOPRALENE 180 SP vapor barrier was heat-applied. This particular vapor barrier is commonly used in northern Ohio when reroofing.
Following the vapor barrier, the installation package was ready to be glued down using DUOTACK, SOPREMA’s low-rise foam adhesive. SOPRABOARD cover board was applied, followed by a layer of heat-applied SOPRALENE Flam 180 and then a heat-applied cap sheet of SOPRALENE Flam 180 FR GR. To finish the project, ALSAN RS 230, a PMMA two-part rapid-curing liquid flashing product, was applied over top in a custom color to match the roof to the aesthetic of the building.
Roof System Manufacturer: SOPREMA
Open since 2002, the Hilton Garden Inn stands 11-stories high and has 240 rooms. The hotel is within walking distance to Progressive Field and the CSU Wolstein Center, and is close to other downtown Cleveland entertainment and dining. The hotel features a business center, pool, fitness center and more. The reroofing project took place in summer 2014.
Fulton County, Ga., administrators believe policy drives the conditions in which people live and work. When socio-economic conditions are poor and there are few public services, administrators believe the physical and mental health of community residents suffer. As such, in 2008, Fulton County’s Health and Human Services departments were charged with identifying opportunities to improve community health through programs and policies.As part of the resulting Common Ground initiative, county administrators now are providing services to underserved areas. Adamsville, a predominantly African-American neighborhood located on the southwest side of Atlanta, was identified as a community in need. Fulton County’s solution was construction of a hybrid building that not only provides primary-care, dental and behavioral health clinics, but also offers child-care facilities, housing resources and access to the library system, as well as a workforce development center. The space also has approximately 500 square feet available for future use. The county hoped the new building would not only provide assistance to residents but also entice additional businesses and housing development in the area.
Although the project was smaller—34,000 square feet—than most completed by the Atlanta offices of architectural firm Stanley Beaman & Sears and general contractor Whiting-Turner Contracting, the design-build team was attracted to the concept. “We thought it was a good story,” says David Deis, project manager with Stanley Beaman & Sears, a firm that specializes in healthcare design. “It’s kind of a community center that taps into all that Fulton County has to offer, and we were both intrigued by that.”
As the team got started, it quickly realized putting all the disparate parts and pieces together into one facility during the 275-day timeframe Fulton County required was going to be challenging. Teamwork and a roof that identifies this “beacon for the community” brought it all together on schedule and within budget.
ROOF AS METAPHOR
As the design-build team began laying out the building’s program requirements, team members realized something had to organize the many services the new Adamsville Regional Health Center would provide. Deis says the team devised an interior “street” visitors can walk down to access the individual departments. “Visitors can see where the dental clinic is, where the primary care and behavioral health are,” he says. “It’s almost like you’re walking down the mall or a street and you’re seeing all these services.”
The team immediately knew the roof would be important. Not only would it be like a “quilt” bringing all the departments and services together in one space, but it also would be a predominant feature on the site.
Built along Martin Luther King Jr. Drive, a state highway that leads into downtown Atlanta, the building would be seen by a lot of traffic. The site itself is street level next to Martin Luther King Jr. Drive but dramatically drops farther from the street. The design-build team opted to create a 2-story building in which the second story is level with the roadway. Parking and access to the first level were built in the back where the site plummets. The location of the building and the site’s topography dictated a roof that would capture the attention of passersby.
“Once we set the building and looked at it formally, we didn’t want people driving down the street and looking down onto a typical gable-type roof,” Deis says. “We knew the roof would be very dominant and we wanted to keep it clean and allow it to claim the corner at the intersection.”
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