Richard gets up close and personal with one of Charlestown's most iconic structures—the Zakim Bridge. Tom shows Kevin how he'll have to modify the old chimney for the new gas fireplace units, and they see the framing of the new bump out for the breakfast area. Mason Mark McCullough presents options for rebuilding the decaying retaining walls and then installs the homeowner's choice: an interlocking concrete system with a bluestone cap. Norm visits a salvage yard in Boston's South End that has dozens of architectural elements from the Greek Revival period. Richard shows Kevin the progress on the rough plumbing and electrical.