If a “cookie” is a small text file that provides information about a website’s use, what small thing provides information about a historic portico?
That would be a cookie wrapper.
The portico at Drayton Hall, the historic 18th-century house on the Ashley River, was repaired with large concrete beams sometime during the 20th century, but those in charge of caring for the museum house weren’t sure exactly when.
But when workers recently began removing that concrete as part of a larger renovation project, they discovered a small piece of red paper.
On it was printed a Nabisco logo, and Trish Smith, Drayton Hall’s curator of architectural resources, says that logo was used from 1923-41. As a result, the best estimate now places the portico repair no earlier than 1923 and not much later than 1941.
“This was key,” Smith says of the find. “Very helpful.”
It is just one interesting discovery as the approximately $450,000 renovation gets underway, one designed by structural engineer Craig Bennett and being built by Richard Marks Restorations Inc.
Visitors have been able to see the failing concrete beams — chunks of which had spalled off as its steel rods have rusted and expanded — for at least a decade. They may have missed other signs of the portico’s problems, such as stucco cracks on the lentils over the first floor columns and the slight bow of the two outer limestone columns and supporting brick columns.
The work is designed to address all of those problems, first by removing the concrete floor and replacing it with a new series of joists made from salvaged, old-growth wood. The joist pockets will be lined with copper or lead to protect the wood from the bricks’ moisture, and the new wood decking will get a hidden, waterproof membrane to direct rainwater away. The checkerboard sandstone and limestone pavers will be replaced — except for the marble pieces.
Just as Smith and others weren’t sure of the concrete, they’re even less sure of the portico’s original construction.
“Was it stone on wood, or was it totally a wood deck? We can’t tell,” Smith says. “The solution we’ve devised is something we think could have been used historically. And it has no concrete.”
The work also includes new support for the second-floor portico. When workers wanted to assess if the brick wall under the stairs could hold an additional load, they removed a brick and drilled a hole large enough to insert a camera.
Its images showed part of the house that was sealed up possibly before the American Revolution, including a vaulted space that supports the stairs and mysterious brick rubble on the ground.
The hope is the new portico will last a century, though its design will allow much more incremental repair as needed than the current work.
This construction is scheduled to finish later this year. Until then, the house’s most iconic facade will be a construction zone, though the museum house remains open for tours.
It may look like a bit of a shock, as Drayton Hall’s acting executive director Carter Hudgins Jr. notes, “This is a little more dramatic than anything we’ve done before.”
Those most familiar with the home, widely considered one of the best ever built in Colonial North America, may realize this new work marks a change in philosophy as far as how best to conserve the house.
Previously, that philosophy was to preserve its fabric as much as possible as it was handed down from the Drayton family to the National Trust for Historic Preservation in the 1970s.
But that philosophy, if followed without question, would cause Drayton Hall to rebuild a concrete addition that has damaged the house, and not to provide hidden structural re-enforcement to cope with its modern reality of welcoming about 60,000 visitors each year.
And that would leave the home with no good choices. If a steel I-beam isn’t inserted in the space between the first and second floor portico, then visitors should not be allowed to walk on it — or Drayton Hall will be rolling the dice of a disastrous collapse.
“Stone doesn’t give you a warning if it fails,” Smith says. “If it fails, it fails suddenly and catastrophically.”
Even though the I-beam will be hidden, Smith says the work is a little more intrusive than Drayton Hall would like. “But we’ve been trying to think about our character-defining features and how do we adjust our philosophy to maintain them. We think this is an acceptable trade-off.”
So in the long run, preservation involves more than repairing, repainting, reroofing and the like.
It also involves rethinking.
Reach Robert Behre at 937-5771.