Keeping the Science Center’s Planetarium Dry, Safe, and Open

When one of the country’s most important planetariums needed a new roof, there was no room for mistakes.

For generations of St. Louis families, the Science Center is where curiosity starts. It’s where kids see their first planetarium show, look up at the stars, and walk out asking bigger questions than they walked in with. And at the heart of that experience sits the James S. McDonnell Planetarium, a landmark that has inspired millions since it opened in 1963.

When the planetarium’s roof began to fail, the stakes were unusually high. Moisture had saturated the existing system and leaks were starting to form. A full tear-off was unavoidable. Inside the building sat a $1.6 million opto-mechanical star projector and a 360-degree domed screen system that absolutely could not get wet, not for a moment.

The roof itself added another layer of complexity. Perfectly round, slightly bowl-shaped, with an interior penthouse and five-foot parapet walls all the way around, this was not a standard commercial roof. Original drawings lacked key dimensions. Concrete step-offs were hidden beneath the existing system. Designing tapered insulation, flashings, and terminations for a 30-year solution required precision and flexibility.

On top of that, the planetarium hosts daily school programs, public presentations, and special events. Work couldn’t happen during business hours. Everything had to be planned around the Science Center’s schedule, not the other way around.

Bade Roofing approached the project with one priority above all else: protection. Before removing the existing roof, we installed a SureMB 120TG base ply temporary roof system. That temporary system acted as a full secondary line of defense, allowing us to remove the entire roof at once without relying on risky nightly tie-ins. The sensitive equipment inside stayed protected throughout the process.

With the temporary system in place, our team could accurately assess the hidden conditions, finalize the tapered insulation layout, and make adjustments before materials were ordered. For the final roof, a 90-mil EPDM system was selected. Its flexibility made it ideal for the planetarium’s curved shape, and it delivered the long-term durability and 30-year warranty the Science Center required.

Because daytime work wasn’t an option, the crew worked nights. Light towers illuminated the roof as work continued from early evening into the early morning hours. A larger crane was brought in to clear the parapet walls, safely remove tear-off material, and load new materials without disrupting the facility below.

The result is a roof system designed for the long haul, installed without a single compromise to safety or operations. The planetarium stayed protected. Programs continued. And one of St. Louis’s most important educational landmarks gained a roof that will quietly do its job for decades to come.

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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. 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. 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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The Science Center and the architect both have a history of using EPDM on their projects because they’ve had a lot of success with it. And with the uncommon design and shape of this roof, EPDM was perfect to mold into all the unique angles and it did a good job conforming to the many curves of the building. We used a 90-mil EPDM to get the 30-year warranty the Science Center wanted and for the overall longevity of the roof.

Work couldn’t take place during business hours.
For this job, we brought in light towers and worked from about 5 pm until 2 or 3 o’clock in the morning.

The entire roof is surrounded by 5-foot-tall parapet walls, making tear-off and loading material extra complicated.
We brought in a larger crane that could clear the parapet walls to remove the tear off and load the new material.

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