Sacramento Zoo to bolster historic entryway after roof problems emerge

The Sacramento Zoo will install temporary braces to shore up three historic structures that have distinguished its entryway since 1961.
The Sacramento Zoo will install temporary braces to shore up three historic structures that have distinguished its entryway since 1961. Sacramento Zoo

The Sacramento Zoo this summer will attempt to preserve three signature structures built in the Space Age by installing long metal supports to address roof problems that emerged last year.

A city inspection determined that the roofs suffer from dry rot and are exposed to the elements. That prompted concerns about their structural integrity and that they will continue to degrade as they remain vulnerable to air, rain and rodents, according to a city staff report.

The three structures with rare architectural forms known as hyperbolic paraboloids have distinguished the main entrance of the zoo since their construction in 1961.

“Viewed from the air, they just look like a square, but if you think of them in three dimensions, and you pull two corners up and two corners down, you wind up with a hyperbola and a parabola together,” said Jon Marshack, vice chair of the City of Sacramento Preservation Commission.

The two smaller structures cover the zoo’s ticket booth, entrance and exit, which remain in use.

But the roof problems have forced the closure of the Discovery Room, which sits under the largest structure. The zoo in past years has relied on the Discovery Room to provide an air-conditioned space where children participating in zoo camps can take shelter from the heat.

This summer, the zoo has designated the Kampala Conference Room, a place normally reserved for meetings, as a temperature-controlled area for children to cool down on extra hot days, according to zoo spokeswoman Tonja Candelaria.

The zoo plans to install steel pipes with concrete bases to support the roofs, as well as reseal the exposed areas. That work will be done over the next two months, after which the Discovery Room can reopen, according to Candelaria.

It will be a temporary fix. The zoo has not yet determined a long-term plan for preserving the entrance area.

According to a 2011 historical evaluation report by the consulting firm Mead & Hunt, “The interconnected buildings are an important, rare and intact example of Mid-Century Modernism in Sacramento.” The report notes that the buildings are “recommended individually eligible for listing in the National Register, California Register and Sacramento Register.”

“Many older patrons have fond memories of entering past those distinctive peaks when they were just children,” Candelaria said. “Now as they bring their own children and grandchildren to the Sacramento Zoo, it is comforting for them to see the same structure.”

A permanent solution would require the zoo to install new steel brackets and sheaths, replace plaster and drywall and construct a new roof membrane, according to the city staff report.

No long-term cost predictions are available, but according to Candelaria, the zoo is considering many possibilities, including completely revamping the entrance design. Candelaria said, “The zoo serves half a million visitors every year, and the entry was not built with these numbers in mind.”

Randi Olson, who was visiting the zoo Thursday, said she is fine with a complete renovation.

“If they’re ready to crumble, they might as well replace them with something stable,” she said.

Other zoo patrons hope that the structure can be saved.

“Nostalgia is really important to somebody who has heritage here,” said Karen Myers. “It’s definitely from my era of the late ’50s and ’60s – pointy architecture, space travel architecture. I think that that’s really important. If they had to rebuild the whole entrance, it would be nice to go with a similar design.”

Emily King: 916-321-1038