JAMES S. MCDONNELL PLANETARIUM, ST. LOUIS
RETROFIT TEAM
ROOFING CONTRACTOR: Bade Roofing Co. Inc.
MATERIALS
Located in Forest Park, a 1,300-acre public park operated by the city of St. Louis, the planetarium opened in 1963 and is free to the public. Its existing roof was saturated and starting to develop leaks, so a total tear-off was required. However, the planetarium houses sensitive equipment that cannot get wet, including a multimillion-dollar projection system that displays on a 360-degree domed screen.
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 flashings and terminations. Concrete step-offs around the perimeter of the building were under the existing roof and, because there were no dimensions on the original plans, creating the tapered insulation layout was challenging.
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. Instead, the roofing crew worked from 5 p.m. until 2 or 3 a.m. each night.
Complications continued because the entire roof is surrounded by 5-foot-tall parapet walls, impeding tear-off and loading of materials. Bade Roofing brought in a crane that could clear the parapet walls to remove the materials that were torn off and load the new materials.
After tear-off, the crew primed the concrete deck with CAV-GRIP 3V and then installed SureMB 120 TG Base Ply/Temporary Roof to ensure the expensive equipment inside the building would be protected throughout the installation process. After that, the crew used Flexible DASH Adhesive to install a base layer of 2-inch SecurShield polyiso, followed by a layer of tapered SecurShield polyiso, also adhered with Flexible DASH. SecurShield polyiso’s coated glass facers improve the product’s fire and moisture resistance, as well as dimensional stability. Then Flexible DASH was used to install a coverboard, followed by the 90-mil VersiGard EPDM over top of the coverboard. The EPDM, which was installed with G200SA bonding adhesive, offers a 30-year warranty.
PRIMER, TEMPORARY ROOF, POLYISO, ADHESIVE AND EPDM MANUFACTURER: Versico
PHOTO: VERSICO