The Upper and Lower Pontalba buildings are two of the most historic buildings in New Orleans. They line the up river and down river sides of Jackson Square at the heart of the French Quarter, and are believed to be the oldest apartment building in the United States.
The Upper Pontalba Building has a second floor gallery that has tongue and groove wood decking that spans across wood purlins on iron outriggers. The gallery is supported below by cast iron columns and have ornate iron railings and panel columns above that support a covered roof canopy above. The wood beam that spans between the cast iron columns is vulnerable to rot and deterioration, especially where the beams connect at the columns.
The panel columns, consisting of two parallel vertical iron square bars with ornamental cast iron components between, rests on a flat iron plate. This plate, which is completely invisible because it is buried inside the beam, sits on top of an iron post that attaches the top of the cast iron column to panel column above. The wood beam bears on the iron plate on top of the cast iron columns. The wood beam consists of a core beam, which spans from column to column; a thick outer fascia that runs continuously across the front face of the beam and splices the beams on each side to each other; and an inner fascia that provides a bearing surface for the iron outriggers.
The detail above shows the collaboration efforts of myself and a restoration contractor to provide a fix that would outlast the previous repair, most likely done during the WPA.
Our solution was to replace the beam core with a new piece of pine timber, pressure treated for ground contact, and with the ends cut and notched and wrapped with W. R. Grace’s Ice and Water Shield. In addition, the top of the beam would be covered with the Ice and Water Shield with some excess provided on the outer side so that it can also be lapped over the outer fascia, and the top of the cast iron column cap plate would be covered with the Ice and Water Shield with excess turned up onto the iron post that supports the panel column above. The wood trim under the decking edge conceals the edge of the Ice and Water Shield where it laps over the top of the outer fascia. The outer and inner fascias, and the wood trim under the decking edge are cut from Spanish Cedar, a wood species that is more resistant to deterioration than other species.
Hopefully, this solution will last 50 years or more.