An American in Paris: the carpenter from New England helping rebuild Notre Dame Cathedral

5 years since a fire ravaged Notre Dame Cathedral. Hank Silva a carpenter from New England helped rebuild the roof made by medieval craftsman. It still doesn't feel real. I'm honest, it's still a bit bit of a dream really. Hank belongs to carpenters without borders to restore historical structures, the world over. And last year he watched overwhelmed as the trusses he crafted which transported and lifted into position. What was it like to watch that to see a trust of that scale. Hand hewn peg together flying through space, it's it's a really out of time kind of experience. A journey that took him to the top of the cathedral following in the footsteps of carpenters from 800 years past for 5 years only a select group have been allowed inside Notre Dame as NBC News was last December. So this is the fire that went crashing down. We all watched it all around the world. We first met Hank last summer at a workshop in northern France painstakingly crafty the roof beams. In the U.S. we have a built tradition that's much newer but that is derived from these European methods being able to work on this building which is the birth of this technique particularly meaningful. Using replicas of medieval tools like these axes Hank and his colleagues reconstructed each trust exactly as they were made in the 13th century. Almost we've had to recreate all this thing because all these inconsistencies all these deformations that have accrued over the centuries. For Hank helping transform Notre Dame has changed his life. For the rest of your life you can come here. Yeah, I look at this. No that you had a part in it. I'll be dining out on this. And 5 years on clear signs, the medieval landmark is now nearing the finish line. Kier Simmons NBC News.