Mission Conversion Focuses on Seismic Retrofit

Dec 20, 2012

The Carmel Mission Basilica
Scaffolding and protective plastic covers the Basilica during the seismic retrofitting.
A sign at the Basilica alerts visitors to the unreinforced masonry.

California’s 21 Missions are older than the state itself, and most could not withstand a major earthquake. Many are made of adobe and date back to the late 1700s when Spain’s king sent Franciscan missionaries to convert natives.  Today conversion at the missions isn’t about religion; it’s about seismic retrofitting.

A heavy, wooden door opens into the garden courtyard of the Carmel Mission.  The 220-year-old Basilica stands at the far end.  The crooked star-shaped window above the entry is said to symbolize that only God is perfect.  “It’s the architecture, I think, is really what brings me here,” said  Tamar Sekayan. She and her husband Justin made the drive from San Francisco.  Like many Californians, she learned about the missions in elementary school.  “I like going to all of the missions.  It’s part of California history, one I grew up with, so we wanted to stop in a check it out,” said Sekayan.

These days the sounds and sights of construction are just as noticeable as the centuries old architecture. The Basilica is in the middle of a seismic retrofit.   So workers removed the red tile roof and replaced it with scaffolding and a protective plastic.  “They’re going to try to put them back in the same way that they were before because you’ll notice if you look at this roof, there’s different patterns of how they’ve faded,” said Vic Grabrian, President of the Carmel Mission Foundation. Grabrian is in charge of raising the money needed to restore this National Historic Landmark.  “We have to be so careful to preserve everything. When we finish, the $5-million seismic retrofit, you won’t be able to tell we did a thing,” he said.

The project involves drilling more than three-hundred vertical and horizontal holes into the five-foot thick walls of the Basilica and inserting steel rods.  “They go all the way down into the foundation, so in a sense tie all those walls together so that if there’s movement the building will resist that and stay intact,” said David Wessel with the Architectural Resources Group, a historical consultant on the project.  Wessel says in restoration, they have to pay close attention to the materials used,  so the Mission doesn’t lose its character and patina of age. “What that entails is the types of mortars that we’ve selected for repairing the cracks, and the voids that have developed over time,” said Wessel as he talks about work on the dome that sits atop the Basilica. “And we’re actually also developing a lime wash that will go over the top of the dome so that will protect it from the rain and the moisture and the filtration,” he continued.

The last restoration on the Carmel Mission ended 60 years ago.  All of California’s 21 missions have undergone some sort of work, but like Carmel, most need further repairs.  Dr. Knox Mellon is the Executive Director of the California Missions Foundation. He says part of the challenge is location.  “Most of them are located along Highway 101, which there are many earthquake faults.  In retrospect, they couldn’t have picked a worse place, the founders to found the missions than the path they did,” said Mellon. He describes the Missions as California’s pyramids, and certainly worth protecting. The foundation is working to assess the condition of each mission.  “We don’t’ have a clear, seismic map of the condition of every mission.  Some are better than others. It cost money just to find out what’s wrong before you can even think about fixing it,” said Mellon.

At the Carmel Mission, the seismic retrofit is just the beginning.  Fundraising is still underway for the complete $20-million restoration of the whole Mission complex.