ST. LOUIS, Mo. — Employees of  The Laclede Group, headquartered in the redeveloped General American Building in downtown St. Louis, have a new open rooftop space to enjoy, with views of Busch Stadium and the Old Courthouse thanks to an innovative green roof installed by local specialists at Bade Roofing Company.

Located at 700 Market St., the former General American Building (known today as 700 Market) originally opened in 1979. The six-story structure is the only St. Louis building designed by acclaimed 20th-century American architect Philip Johnson.

Bade Roofing worked with St. Louis-based general contractor Tarlton Corporation and real estate developer Koman Group to create a rooftop garden courtyard on the building’s 5th floor, as well as re-roof its 6th floor. A green roof provides insulation, lowers the need for heating and cooling, and can help manage storm water. The project is currently pending LEED Certification by the U.S. Green Building Council (USGBC).

The Project

Bade crews began the challenging and complex 17,800 square-foot project by first removing the existing paver ballast — which included two inches of EPS insulation and a 2-ply SBS modified roof system — down to the structural concrete deck. They then installed a new 115-mil, fleece back loose-laid TPO roof system manufactured by Firestone Building Products.

Installers 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 and pre-planted “Green Bloc” vegetation trays and leveling pedestal system.

The outdoor space incorporates raised areas filled with growth medium; various trees and shrubs planted in planter boxes; a fescue lawn area; seating areas with lighting; a watering system; and a gas fire pit. A two foot-wide buffer of landscape gravel was also installed around the roof’s perimeter between the pavers and the parapet wall to aid with the courtyard drainage.

One of the biggest challenges to Bade’s crew was ensuring that 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 for 24 hours to test for water tightness. Insuring 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. 

Re-roofing of the 6th floor roof started with the removal and disposal of the existing gravel ballast and protection mats. The roof’s two-inch EPS insulation was removed and set aside for re-use later on the project. Bade crews then installed a 60-mil ballasted EPDM roof system by Firestone Building Products, using the saved two-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 by Firestone Building Products.

The Company 

Dave Bade is the owner of Bade Roofing Company, Inc. Founded in 1954, the company is one of St. Louis’ premier family-owned and operated commercial and industrial roofing specialists. Complete with a highly-trained and skilled union workforce, Bade installs the highest quality roofing systems on major retail centers, grocery stores, hospitals, schools, warehouses and office buildings.

Working directly with facility managers and building owners, and in partnership with local architects, designers and roofing consultants, Bade Roofing also provides comprehensive roof inspections and survey reports, leak finding and repair services, green roof installation, and licensed asbestos roofing removal and abatement. Visit www.baderoofing.com for more information.