A Living Roof for One of St. Louis’s Most Iconic Buildings

A complex green roof system designed to honor a landmark building and support modern use.

Some buildings are more than addresses. In St. Louis, the former General American Building at 700 Market Street is one of them.

Originally opened in 1979, the six-story structure is the only building in St. Louis designed by Philip Johnson, one of the most influential architects of the 20th century. Its recent redevelopment transformed it into a new home for employees of The Laclede Group, now known simply as 700 Market, while preserving the architectural significance that makes the building a downtown landmark.

Bade Roofing was proud to be part of this transformation, working alongside Tarlton Corporation and The Koman Group to deliver a roofing solution that matched the ambition of the project.

The existing roof system had reached the end of its life. Moisture saturation and active leaks made a full tear-off unavoidable. But this was not a simple replacement. The project required two very different roof environments, each with its own performance and design demands.

On the fifth floor, the vision was a green garden courtyard. Over the new TPO roof system, our team installed three layers of loose-laid EPS insulation and a protection mat to prepare the surface for a patterned, three-color concrete paver system, wood pavers, and pre-planted Green Bloc vegetation trays. These elements were set on a leveling pedestal system, allowing for precise drainage and long-term flexibility. Trees in planter boxes, raised planting areas filled with growth medium, shrubs, and a fescue lawn completed the space, turning the roof into a functional outdoor environment. A two-foot-wide gravel buffer was installed at the perimeter between the pavers and parapet walls to support proper drainage across the system.

The sixth-floor roof presented a different challenge. The existing gravel ballast and protection mats were removed and hauled away. The original two-inch EPS insulation was carefully removed and saved for reuse. A new 60-mil ballasted EPDM roof system was then installed, using the salvaged insulation, followed by new protection mats and fresh gravel ballast. This approach balanced performance, efficiency, and responsible material use.

Throughout the project, every detail mattered. From drainage and load considerations to plantings and walking surfaces, the roof had to function as both infrastructure and experience. The result is a layered system that protects the building, supports daily use, and adds real value to the people who work there.

At 700 Market, the roof isn’t just something overhead. It’s a living part of the building, designed to last and built to be enjoyed.

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The roof had to be torn off, but the $1.6 million projection system inside the building absolutely could not get wet.

Bade Roofing decided to go with a SureMB 120TG Base Ply/ Temporary Roof to ensure the expensive equipment inside the building would be safe and protected throughout the installation process. Of the decision to use SureMB 120TG, Drew Bade from Bade Roofing says, “It was a secondary line of defense that allowed us to remove the entire roof all at once and not have to rely on tie-ins from the old roof to the new one when the crew started and stopped each night.” Concrete step-offs around the perimeter of the building were under the existing roof, and there were no dimensions on the original plans, so creating the tapered insulation layout was tough. Drew Bade says, “This is another reason we decided to use the SureMB 120TG; it allowed us to really see what was going on with the tapered and make adjustments prior to ordering.” The roof itself is perfectly round, yet slightly bowl-shaped, making it difficult to design a tapered system, flashings, and terminations for this 30-year project.

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