Exclusive photo gallery: An up-close look at Jefferson Memorial's $14 million restoration

WASHINGTON (7NEWS) — The scaffolding is finally coming down around the Thomas Jefferson Memorial after two years and $14 million dollars of renovations.

7News was given exclusive access to the three stages of cleaning and repairs. Reporter Victoria Sanchez took you to the top of the dome, 130 feet above the Tidal Basin, in December 2019, July 2020,and now in April 2021.

Construction crews and stone specialists turned the blotchy building into a sparking structure once again. Biofilm, made up of bacteria, algae and fungi, was first spotted on the memorial in 2006. It continued to grow, creating dark patches all over the weathered Vermont marble.

The National Park Service studied viable and environmentally friendly solutions and came up with a possible problem solver. In 2017, the NPS tested a new technique using laser beams. A 1,000 square foot test area on the dome was worked on between September and October 2017. The stark strip stood out until the rest of the 10,000 square foot dome was completed.

“This biofilm is a bit of a mystery,” said National Mall historic architect Audrey Tepper during the 2019 tour. “It just loves it here and it’s very visible for all to see.”

Tepper said the National Park Service isn’t clear why it started developing.

The monument overlooking the Tidal Basin was surrounded by an intricate maze of steps and ladders to allow crews to access parts of the normally inaccessible structure.

“It’s good exercise, I’ll tell you that,” said Construction manager Michelle Nedd on Thursday.

Nedd and Mike Litterst of the National Park Service took 7News on the third and final tour of the exterior renovation. That meant once again climbing the scaffolding to the top.

On each level, there are crews putting the finishing touches on the project. It took elbow grease, a lot of steam, and painstakingly slow laser cleaning.

“We’re not talking about Star Wars lasers here,” Tepper said in 2019. “We’re talking about lasers specific to cleaning stone.”

The high-tech laser is not quick, cleaning just two square feet an hour.

“People equate it to cleaning the memorial with a toothbrush,” she continued.

The view from December 2019 to April 2021 is awe-inspiring.

For a closer look, Nedd walked Sanchez to the top of the roof.

Just above the roof portico, the shine of the 10,000 square foot dome is hard to miss. While it is the most visible, there are other details that went into the $14 million project, including some cosmetic work on Jefferson himself, but not the towering 19-foot-tall statue.

“Very few people look up into the pediment and see the sculpture of the Committee of Five. Those are the five men that drafted the Declaration of Independence,” Litterst explained.

The nose of Jefferson in that sculpture had a crack and was repaired.

“Little nose work done. He’s good to go for hopefully the next 75 years,” Litterst said.

Through steam cleaning and lasers, the biofilm was removed, though it’s not clear how long it will last.

While the biofilm was the most apparent problem, in 2014, structural damage came to light.

“A stone here in the portico gave way in the middle of the night and fell in the plaza. Thankfully, nobody was here, no one was injured,” Litterst explained.

The new roof could last three decades, making this trip to the top one of the last for years.

While the exterior work wraps up, you’ll still see construction crews at the Jefferson memorial.

Philanthropist David Rubenstein donated $10 million to redo the underground museum, add new bathrooms and increase the number of accessible entrances for those in wheelchairs or who have a hard time climbing stairs. The history of Thomas Jefferson will also be updated to include his past of slave ownership.