Ever since it acquired Drayton Hall a generation ago, the National Trust for Historic Preservation has lavished the utmost care on preserving all of the plantation home's historic fabric.

That's why it might come as a shock that workers are now ripping out its piazza ceiling.

“We've got some construction going on,” Carter Hudgins Jr. says recently as preservation technician Trish Smith and Kendy Altizer peel ceiling boards from the joists, creating a small cloud of dust each time.

Despite Drayton Hall's status as one of America's first and finest examples of Georgian Palladian architecture, it has much in common with Charleston's other old homes: It needs regular maintenance, especially on the piazzas, which bear the brunt of the searing sun and driving rains.

Hudgins, director of preservation and education, says structural engineer Craig Bennett is reviewing the soundness of the piazza, and while his report isn't done, it's clear that portions of the piazza are holding moisture and beginning to rot.

“The paint is actually holding the boards in place,” Hudgins says of the second-story piazza floor and first-story piazza ceiling. “It's sealed up and it's deteriorating the planks.”

That's why the current plan is to leave the ceiling boards in storage and the joists exposed for several months, possibly longer, until Hudgins, Bennett and other members of Drayton Hall's team settle on a long-term fix.

In other words, Drayton Hall's most famous facade will have a work-in-progress look for a while, particularly up close, but leaving the unpainted joists exposed should extend their lifespan by allowing them to dry out faster after a soaking rain.

“That should breathe a lot better, letting the moisture work through the system,” Hudgins says.

Ripping off the ceiling also will expose the piazza structure, reveal how it evolved over time and help experts decide how best to fix it.

What's there now is at least the second version: Where the ceiling already is gone, one can see patches in the main house's brick where earlier joists tied in.

Also, earlier images of the house provide clues about how this piazza was modified several times during the 19th century.

The current ceiling that's being removed is a sort of dropped ceiling, installed sometime in the 1880s or 1890s several inches lower than the original (the ceiling on the piazza's second floor is thought to be much older; the house's roof has offered better protection for it over time).

Workers also have chiseled off some cracked stucco from the sandstone lintels to review their condition. Fortunately, Hudgins says, the cracks were simply failing stucco, and the massive stone supports are intact.

The real challenge lies in the basement, where a series of concrete and rebar beams, installed in the early 20th century, are failing and thereby undermining the support for the piazza's first floor.

Workers soon will install support cribbing in the basement to prop up those beams until a long-term fix is found.

While the National Trust's goal has been to preserve Drayton Hall's fabric as is, if those concrete beams are causing damage elsewhere, they will need to go. But if they go, what should be put in their place?

There are more questions than answers at this point, but executive director George McDaniel says Drayton Hall wants to be pro-active in fixing its structural issues.

“We want to avoid what has happened at sites like Mount Vernon and Monticello, where they've had to replace timbers with steel,” McDaniel says.

It's unclear what will be the ultimate solution to the piazza's structural problems, what it will cost and when it will restore this house to its previous look, but in the meantime, Hudgins hopes visitors can look past the missing ceiling and appreciate the additional construction that now can be seen.

“You might think, 'Uh, the bones of the house. That's ugly. That was never meant to be seen,' but it also allows guests to see how the house was constructed,” he says. “Drayton Hall always has had layers. This allows the guests to see more of those layers.”

Reach Robert Behre at 937-5771.

Editor's note: Earlier versions of this story incorrectly identified the sandstone lintels. The Post and Courier regrets the error.