A Green Roof for the Iconic 700 Market Building

Employees with The Laclede Group have a new place to call home in the recently redeveloped General American Building at 700 Market Street, now known as 700 Market.

Originally opened in 1979, this six-story structure is the only St. Louis building designed by Philip Johnson, one of the most acclaimed 20th-century American architects.

Bade Roofing was proud to be a part of this project, working with Tarlton Corporation and The Koman Group.

The Challenge

The existing roof was saturated with moisture and was starting to develop leaks, so a total tear-off was required.

However,the planetarium houses sensitive equipment that CANNOT get wet: a multimillion-dollar projection system that displays on a 360-degree domed screen. There were concrete step-offs located under the existing roof around the perimeter of the building, and there were no dimensions on the original plans, so creating the tapered insulation layout would be especially tricky. The roof itself is unusual; it’s perfectly round, yet slightly bowl- shaped, with an interior round penthouse. The unique shape made it difficult to design a tapered system, flashings, and terminations for this 30-year project. The facility hosts daily educational presentations for school children, as well as special events and exhibits, so work couldn’t take place during business hours. The entire roof is surrounded by 5-foot-tall parapet walls, so tear- off and loading material would be complicated.

The Solution

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.

Green Garden Courtyard - 5th Floor

Stacked three layers of loose-laid EPS insulation and a protection mat over the new TPO roof system, in preparation of patterned three-color concrete paver system, wood paver, and pre-planted “Green Bloc” vegetation trays that were installed on a leveling pedestal system, including trees in planter boxes and raised areas filled with growth medium, planted with various shrubs, plants, and a fescue lawn area.

Installed a two-foot wide buffer of landscape gravel at the perimeter between the pavers and the parapet wall to aid in draining of the system

6th Floor Roof

Removed the existing gravel ballast and protection mats and hauled away.

Removed the existing two-inch EPS insulation and set aside for reuse.

Installed a 60-mil ballasted EPDM roof system using the saved two-inch EPS insulation, and installed protection mats with new gravel ballast.

Project details


The Laclede Group


700 Market St., Downtown St. Louis


New Green Roof & Re-Roof 6th Floor


Firestone 115-mil fleece back TPO with landscape overburden 60-mil ballasted EPDM roof system


Green Roof Level 3.7 (17,800 square feet) • 6th Floor Roof (17,800 square feet))

1. Growth Media

2. Filter Fabric

3. Drainage Media/Gravel

4. Protection Fabric

5. Root Barrier

6. Insulation with Drainage

7. TPO

8. 1/2" DensDeck Prime

9. Approved Insulation

10. Substrate

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