700 MARKET, ST. LOUIS
Bade Roofing was challenged with creating a rooftop garden on the building’s fifth floor and reroofing its sixth floor.
The crew began the complex 17,800-square-foot, green-roof project on the fifth floor by removing the existing paver ballast, 2 inches of EPS insulation and a two-ply SBS modified roof system down to the structural concrete deck. A new 115-mil, fleece-back loose-laid TPO roof system was then installed and green-roof penetrations were flashed.
Bade Roofing crews stacked three layers of loose-laid EPS insulation and a protection mat over the new TPO roof system in preparation for a three-color concrete paver system, wood paver, preplanted Green Bloc vegetation trays and leveling pedestal system.
One of the biggest challenges to Bade Roofing’s crew was ensuring the green roof was completely waterproof. Any leak in the roof could potentially damage tenant spaces below. “Getting the roof watertight as quickly as possible during each phase of installation included conducting an intensive water test, which involved flooding the roof for24 hours to test for water tightness,” explains David Bade, Bade Roofing’s owner. “Ensuring that the base roofing material was 100 percent watertight was critical on this project. Once the green roof and courtyard components are put in place, repairing a leak becomes incredibly difficult and expensive. Water tests were conducted and any weak areas in the system were quickly reinforced. After that, the roof could be flooded for an indefinite quantity of time and not be compromised.”
Reroofing of the 17,800-square-foot sixth-floor roof started with removal and disposal of the existing gravel ballast and protection mats. The roof’s 2-inch EPS insulation was removed and set aside for reuse. Bade Roofing crews then installed a 60-mil ballasted EPDM roof system, using the saved 2-inch EPS insulation, along with new protection mats and gravel ballast to complete the project.
The roof system was awarded a 20-year manufacturer’s warranty with an overburden removal rider.
Located at 700 Market Street, the former General American Building originally opened in 1979. The 6-story structure is the only St. Louis building designed by acclaimed 20th century American architect Philip Johnson.
Tenants of the redeveloped building have a new rooftop space with views of Busch Stadium and the Old Courthouse thanks to an innovative green roof. The outdoor space incorporates raised areas filled with growth medium, various trees and shrubs planted in planter boxes, a fescue lawn area, seating areas, lighting, watering system and a gas fire pit. A 2-foot-wide buffer of landscape gravel also was installed around the roof’s perimeter between the pavers and the parapet wall to aid with the courtyard’s draining.
PHOTO: Bade Roofing