A Sacramento man is figuring out what to do next with a building he owns in Sonora’s historic downtown district that was deemed as unsafe to occupy by the city after the stacked rock wall on the south side of the building crumbled on April 1.

The city has told Joseph and Lucia Gee, who own the building at 89 N. Washington St., they must make the necessary repair in order for the building to be declared as safe to inhabit again, but Joseph Gee said their insurance company says their policy does not cover the damage.

Gee works as a full-time professor at Cosumnes River College in Sacramento running a pharmacy technology program. He said that he and his wife purchased the building, which included 83 and 87 N. Washington St., as an investment in 2015.

The building at 89 N. Washington St. that was damaged contains one studio apartment and two one-bedroom apartments, all of which are now vacated. Gee said the tenant on the side where the wall collapsed was advised it was no longer safe to stay there and moved out prior to the collapse.

Daren Wardell, the city’s building inspector, said the two apartments on the side of the building where the wall didn’t collapse are not safe to occupy, primarily because the wall that came down took out electrical service to those units.

He said the rest of the building that’s made of brick remains in the same condition as the rest of those in town.

“We posted the building as not to be occupied because of the lack of power and stability of the remaining stacked rock walls,” Wardell said. “He needs to repair or remove the affected areas and restore power.”

Wardell said he became aware of the concerns about the building in mid-January after the owners asked the city what they would need to do to shore up the wall because it was beginning to bulge.

The area received several inches of rain from a major tropical storm on March 22 that led to unprecedented flooding in Groveland, as well as concerns about the potential failure of the earthen dam that holds water back in Moccasin Reservoir.

Wardell said he couldn’t confirm whether the storm contributed to the collapse of the wall more than a week later. However, he noted there must have been outside factors that contributed to the collapse because there are a number of other older buildings in town with walls constructed in a similar way.

“These have been here for over 100 years,” he said of the stacked rock walls.

Wardell said there hasn’t been a survey to determine exactly how many buildings in the city have stacked rock walls, though he noted they are prevalent throughout older areas of California like Sonora.

He suggested that any other building owners with concerns about the conditions of their structures can consult with a structural engineer who can make an assessment of the building’s integrity.

“When you get into this unreinforced masonry, whether it’s stacked rock or brick, you have a risk of it coming apart,” Wardell said.

Wardell also said that although the building is considered historic, the unstable and unsafe conditions allows for its removal if deemed necessary.

Jerry Boone Jr., a master stonemason who has worked with the material for the past 60 years, said that the stacked rock construction dates back to days of the Gold Rush.

The slate used in constructing the walls would come straight out of some of the old mines that run underneath the city and sand used to create the concrete would come from local rivers and creeks, according to Boone.

“There are many buildings downtown that have this type of construction,” he said. “We have all sorts of different buildings that have lots of old slate and brick. It was just a matter of what they had at the time”

Boone said modern day cement is made with sand that’s cleaner and more refined, while 100 years ago they made it out of dirt and didn’t really care much about debris that made the concrete “very inadequate.”

He added that the older methods of construction also created holes inside of the joints between the rock called voids that can be dangerous to the structure’s overall integrity.

“What happens is over time it deteriorates and you get water in them (the voids), which causes expansion and can lead to collapse,” Boone said.

Gee said now he’s concerned for others who own buildings with similar walls because he was unaware that his insurance wouldn’t cover such damage.

He plans on coming to town Saturday to speak with a contractor about fixing a stacked rock retaining wall that’s bulging behind the building he owns at 83 N. Washington St., which houses the Bagel Bin.

“I’m trying to get it done as soon as possible because of the urgency of it,” Gee said.

The work will require digging out some of the hillside behind the building to relieve pressure on the wall, pouring a new concrete wall, and moving some of the propane lines, according to Sarge Eskandary, owner of the Bagel Bin.

Gee said he received an estimate for the project to cost about $5,600.

“Hopefully, they get it fixed so we won’t have to move,” Eskandary said of his business that’s been at that location for 22-plus years.

Contact Alex MacLean at amaclean@uniondemocrat.com or (209) 588-4530.