I didn’t intend to take that picture on a pseudo-artistic slant, but it’s more trouble than it’s worth to straighten it out. The old buildings on the right are pretty much plumb in reality. Also, the picture isn’t reversed – the Stone Street Tavern has this sign painted backwards because this facade, on Pearl Street, is the back of the building.
The building is an 1836 store and loft building, constructed with heavy wood-joist floors and masonry exterior walls. A decade or so later and the storefront would have been built as cast iron; a few decades later, the street facades might have been entirely iron. In this case, the storefront consists of granite piers and lintels, allowing a pretty good percentage of window space. When iron storefronts came along, they pretty much copied this layout but made the piers smaller.
At first glance, the granite lintels seem impressive. They’re clear-spanning a decent distance, which is not something Americans generally do with stone beams. But they’re actually doing less than it seems. There’s a line of windows centered on each of the lintels, and the windows aren’t that much narrower than the storefront windows. If you imagine extending the vertical lines of the storefront piers up to the second floor, the projection of the brick pier beyond the face of the granite pier is maybe a foot or so. That’s easily within the distance that masonry can corbel, so the vertical load path probably would work okay if the lintels vanished. As it is, the lintels serve as one-piece corbels, transferring the load from the upper pier outside edges in towards the center of the lower pier.
We see this kind of construction a lot and it not only works, it works so well it can be eerie. Since the lintel doesn’t need to span, it works even if it is cracked in the middle. (The most common reason for cracks like that is differential settlement of the piers, particularly if the building is located, like this one, adjacent to the old river bank or on old landfill.) It’s odd to see a lintel – which certainly looks like a beam – cracked clear through but still performing, but it makes sense when you realize it’s not really a beam in the structural load-path sense.
