Montpelier Mansion, a National Historic Landmark, will undergo its first major restoration in more than 30 years to repair water damage. (Jamie Anfenson-Comeau/THE GAZETTE)

The 200-year-old Montpelier Mansion historic site soon will get its first major restoration in 30 years to combat moisture problems, according to Maryland-National Capital Park and Planning Commission officials.

Restoration efforts are in the developmental stage. Restoration work is expected to begin in the spring, said Monica Wharton-Henley, M-NCPPC project manager.

“This is going to cut into our programs a little bit, but it has been a long, long time coming and it is definitely overneeded. Old buildings need a lot of tender, loving care,” said Susan Morris, president of the Friends of Montpelier and a longtime volunteer at the mansion.

Officials expect the mansion to be closed for a while, possibly through September, and its educational programs are being hosted by community partners, M-NCPPC Museum Manager Mary Jurkiewicz said.

The mansion also might be limited for weddings, Jurkiewicz said. Montpelier is not taking reservations for spring through September.

Anyone who wishes to tour the mansion is asked to call in advance.

Jurkiewicz estimated the closing will cost about $5,000 in revenue.

The grounds still will be open to the public, unless renovation work dictates otherwise, and the Montpelier Arts Center, on the mansion grounds, will stay open, Jurkiewicz said. She said many residents walk the grounds and enjoy the scenic view, particularly during warmer months.

Montpelier Mansion was constructed in 1781. Only 70 acres remain of the original 9,000-acre property, which played host to several prominent people, including President George Washington and Abigail Adams, wife of President John Adams. In 1983, the house was restored and refurnished as it might have appeared from the late 18th century to 1830.

The restoration is necessary to deal with moisture issues that have worsened in the centuries-old structure, Wharton-Henley said.

Laytonsville-based Oak Grove Restoration Co., which received the $767,000 restoration contract, specializes in historic preservation and conservation of historical architecture using traditional methods, according to the company’s Web site.

“We have to ensure that we have professionals who are experienced in preserving historic buildings,” Wharton-Henley said.

Much of the work will have to be done manually, brick by brick and tile by tile, Wharton-Henley said. Two brick terraces, not part of the original home but constructed in the 1930s, have severe water damage, with erosion on the walls and elevated surfaces. They will need to be removed, she said.

“They were made with modern masonry, which is not compatible with the historic masonry and could be trapping moisture against the original mansion walls,” Wharton-Henley said.

The full extent of the water damage cannot be determined until after work begins, Wharton-Henley said.

“I feel like a sleuth trying to find clues to solve a Montpelier mystery,” she quipped.