National Park Service begins roof restoration, laser cleaning of Jefferson Memorial

WASHINGTON (ABC7) — The National Park Service announced Thursday that it has begun a 15-month project to restore the roofs, repair the stone and clean the marble at the Jefferson Memorial.

The roof restoration and repair will consist of replacing the two-flat upper and lower roofs that circle the dome to keep the building watertight and dry. Additionally, the large marble “tiles” covering the portico, the dramatic front entry that projects towards the Tidal Basin, will be lifted to replace the deteriorated waterproofing below.

Stone will be repaired under the portico and along the colonnade ceilings. Improvements to roof drains, downspouts and gutters will also be completed.

To clean the visible marble on the dome and roof of the Jefferson Memorial, specialized lasers will be utilized to remove the black biofilm – a microbial colony of algae, fungi and bacteria seen growing on upper portions of the memorial.

The biofilm was first noticed in discrete areas of the white marble in 2006 and has become more pronounced in recent years. The National Park Service has studied this growth since 2014 to determine the best treatment options.

Access to the front of the memorial, including the steps, accessible route, chamber with the statue of Thomas Jefferson, exhibit area, restrooms and elevator will remain open to the public during the duration of the project. Some areas, however, like the east side of the memorial, will be closed for construction staging.

The contract for the project was awarded on Sept. 19, 2018, to Grunley Construction for $8.75 million. It’s expected to be completed in its entirety by May 2020.