Mary Hardy climbs a wide staircase leading to the Hearst Gymnasium at UC Berkeley, a neo-classical building completed in 1927. The only collaboration between famed architects Julia Morgan and Bernard Maybeck, it’s listed on four historic registries.

Hardy turns, grasps a baluster — one of the graceful, vertical columns lining the staircase — and pulls. Off comes a chunk of concrete 6 inches high and at least half as wide.

“It’s exploding from the inside,” said Hardy, an architectural conservator who earned one of her two master’s degrees at Cal. “Moisture is soaking in, and it’s like it’s got a disease. Once corrosion starts, it doesn’t stop.”

It isn’t just the stairs. A crack nearly decapitates a carved lion head that glowers down at students walking by the 88-year-old gym. Similar cracks and fissures climb up columns and streak across walls, often exposing rebar, and a barricade of barbed wire obscures much of the gym’s southern wall. Inside the building, weeds grow around a decorative basin too damaged to hold water any longer, lending a dystopian feel to a once lush courtyard. Leaded windows feature spidery fractures, and someone has dropped trash into a ruptured stone ball resting in a cherub’s lap.

Marble-lined pools

Despite the decay, the historic structure is hardly in ruins. It’s got three marble-lined swimming pools and from the roof a killer view of Cal’s famed Campanile. Students use the gym’s high-ceilinged, updated workout rooms to play basketball and practice gymnastics. The ROTC meets downstairs. UC Berkeley has upgraded the building’s electrical wiring, installed fire alarms, replaced its downspouts and refreshed the lighting, among other safety improvements.

Yet the work hasn’t helped the embellishments and architectural features that make the gym magical, such as its cherubs and lion heads and draped Greek women holding garlands — like those at the Palace of Fine Arts in San Francisco, also a Maybeck creation.

UC architects acknowledge in a report that the gym “requires comprehensive rehabilitation to repair and preserve many of the building’s character-defining features, restore obscured or missing features, and correct maintenance and water intrusion deficiencies.”

But that was 10 years ago. The repairs have yet to be made.

Since then, studies have determined that full restoration would cost an astonishing $150 million, said Emily Marthinsen, the campus architect and assistant vice chancellor for physical and environmental planning. Another study says the building could skate by with a mere $50 million face-lift. But no one’s ponied up that money, either.

Only some of those costs would involve seismic upgrades, which are reimbursable by the state, Marthinsen added. The gym also remains low on the state’s waiting list for that funding because it has few users compared with larger projects, she said, noting that it could take a decade before the gym’s turn comes.

And unlike programs such as astronomy or physics, where users have the means to do fundraising for new buildings and improvements, “the Hearst Gym didn’t have a partner with outside resources,” Marthinsen said.

Even students weren’t willing to consider a fee increase to renovate the gym when campus officials suggested it, preferring to support an expanded mental health program, she said.

But critics say the university hasn’t done enough to help the unique building and should let the public know about its poor condition.

“I don’t think you can get a more historical building than that, and they’re allowing it to fall into ruin. That’s what galls us,” said Gray Brechin, a visiting scholar in the geography department who has been swimming at the gym since he was a student nearly 50 years ago.

Brechin loves the building, and says he’s been spoiled by its extraordinary pools lined with white and green-streaked marble from a long-shuttered quarry in Vermont. “I can’t swim over concrete anymore,” he said.

Few repairs made

When the marble cracked nearly 20 years ago, someone at the university found slabs of the original Vermont marble, and repairs were made. Not much has happened since.

Brechin and Hardy, with retired Professor Roberta Park — who taught physical education in the gym since before Brechin began swimming there — have been speaking out about the condition of the building listed not only in the National Register of Historic Places, but also in the State Historic Resources Inventory, as a California Registered Historical Landmark, and as a City of Berkeley Landmark.

“I can’t believe they’ll let it go,” Hardy said the other day as she, Brechin and Park toured the building. “It’s so integral to the history of this university.”

Located on Bancroft Way at Bowditch Street, the gym was built as a sports facility for Cal women and originally planned as part of a “grandiose complex to memorialize university Regent and patron Phoebe Apperson Hearst,” according to a campus guide written by Harvey Helfand, Cal’s former planner.

The complex was to be built by Maybeck, a leader in the Arts and Crafts movement and a UC Berkeley instructor. The gray-bearded master had designed the Palace of Fine Arts for the 1915 Panama-Pacific Exposition in San Francisco and that city’s Swedenborgian Church in 1895, among many other notable buildings. Now he drew up a design for the new campus complex.

But Maybeck’s “picturesque renderings gave little attention to the practical workings of the buildings, and the first drawings Maybeck submitted to the university were unacceptable,” Helfand writes. So Cal’s president, William W. Campbell, and Hearst’s son, the publisher William Randolph Hearst (whose descendants acquired The Chronicle in 2000), brought in Morgan in 1924.

Morgan, one of five architects for San Francisco’s Fairmont Hotel, was also the architect of Hearst Castle in San Simeon and had designed the Asilomar Conference Center in Pacific Grove, among other buildings.

Soon after, however, the publisher announced he had run out of money for the project and only the gymnasium would be built.

Morgan, Maybeck team up

Morgan and Maybeck described their plans for the “Hearst Gymnasium for Women” in a telegram to Hearst, saying it would have “columns like an old temple” and “glass supported by Pompeiian bronze iron,” Helfand recounts in his book.

“It’s definitely an important building — especially being a collaboration between Maybeck and Morgan. It is rare,” said Anthony Bruce, executive director of the Berkeley Architectural Heritage Association. “As far as I know, this is their only collaboration.”

Today, many of the gym’s custom-made copper columns, or colonnettes, are caked with white residue and embedded in broken concrete. The campus replaced its ornamental concrete urns with fiberglass replicas in 1981 when the originals began to deteriorate.

Brechin and others criticize Cal for its multimillion-dollar expenditures on the new Memorial Stadium, an improved Sproul Plaza and other structures like a new law school building, even as they let the gym’s unique features rot away. And they fear Cal administrators will let the building go beyond repair.

Marthinsen insists that won’t happen — though she doesn’t yet know how to prevent it.

Fundraising needed

“I love that building myself,” said the architect, who wrote her master’s thesis on Morgan’s YWCA in Oakland.

She said the campus isn’t allowed to dip into its building funds to fix up the Morgan/Maybeck collaboration.

“A lot of the money is targeted for specific things,” Marthinsen said. “They’re funded by donors who specifically wanted to support them.”

Restoring the building will be tough unless someone takes on the job of fundraising for it, she said.

Brechin said he wouldn’t know how to take on such a job. “That would require tens of millions of dollars. I don’t know those kinds of people,” he said, adding that he does give talks about the building.

Meanwhile, Marthinsen tried to dispel the rumor that the campus plans to knock the building down. “I’ve never heard that,” she said. “We’re continuing to try to find ways to fund the Hearst Gym.

“We agree it’s a fantastic building.”

Nanette Asimov is a San Francisco Chronicle staff writer. E-mail: nasimov@sfchronicle.com Twitter: @NanetteAsimov