Workers stood on a scaffold this week and chipped away at the crumbling mortar between the stones in one wall of the Woodlawn Slave Quarters in Columbia.
They were preparing to fill the space between the stones with new mortar of the same color and roughly the same strength, the latest in a series of steps to restore the crumbling house.
"Our goal is to stabilize the structure and return it to its original [condition] as closely as we can," said Charles E. Grey, project manager for the renovation.
That means reusing most of the rubble found on the site and carefully choosing other materials that will blend in with the approximately 300-year-old walls that remain.
The two-section, two-story structure is thought to date to the early 1700s, when it was part of the Woodlawn manor property. It is believed to be the oldest surviving slave quarters in Howard County.
Years of neglect caused the structure, which sits on Columbia Association property off Bendix Road, to crumble in places, lose most of its roof and be overrun with vines.
The site was added several years ago to Preservation Howard County's list of the 10 most endangered historic sites. A year ago, the Columbia Association convened the Woodlawn Task Force to determine what to do with it.
The task force's efforts and a $225,000 investment by the Columbia Association led to the renovation that began last month.
"We've been working on this for quite a while, and it feels wonderful to see it being done, and to see it being done so well," said Barbara Kellner, a member of the task force.
Kellner, manager of the Columbia Archives, said the committee thinks its research into the history of the site has paid off in a renovation that captures an historically appropriate look and feel.
"It will be a good backdrop for telling the story in the future," she said.
Kellner said the task force wants to create a master plan outlining ways to use the slave quarters for historic interpretation, education programs, archaeological activities and public events.
The restoration began with clearing piles of fallen stone and debris from inside and around the quarters.
Straight-sided cornerstones from the wall, stone window lintels and sills and hearthstones found near the fireplace were set aside on six wooden pallets.
Those stones are key, because the focus of the job "is really copying what's here," said Bernard O'Reilly, site superintendent of the construction team from Worcester Eisenbrandt Inc., a Baltimore company specializing in carpentry, masonry and historic restoration.
The new, 18-inch-thick sections of walls will be built like those that are still standing, with stones layered with mortar. No steel, wire or concrete will help support them.
The workers will use as much of the salvaged stone as possible, but in an effort to make the project more affordable and flexible some new stone taken from a local quarry will be used to fill in less-visible areas.
The challenge is "getting the front of the building to match what is already there," O'Reilly said, "to use the stones found on the site and to put them together as best we can."
"I keep walking around the walls" to look at how they were made, he said. He also consults old photographs of the building.
A base coat of plaster is being added to the interior of the walls to give them more stability, O'Reilly said, and finished plaster is planned. A crumbling fireplace will be rebuilt.
The structure will be completed with wooden trusses and a cedar roof intended to give the appropriate historical appearance, and a loft will be built to re-create the upper story of the quarters.
For the immediate future, the window and door openings will be covered with wood, and a layer of gravel will serve as a floor.
The project is expected to be complete by June.
The task force is planning a celebration May 20. The community will be invited to see the progress being made at the site. A reception at Oakland Manor will include refreshments, entertainment and displays.
O'Reilly has had experience building stone structures. He said that when he heard this project was a slave quarters, "I couldn't resist saying yes to that one."