Hidden Oddity

That’s the demolition of a small commercial building on the Upper West Side. Nothing remarkable – I stopped and looked only because I used to live in the neighborhood and must have walked by this building a few thousand times in the late 80s and early 90s.

I was surprised to see that the roof is made of open-web steel joists. That structural system, basically miniature pre-fab steel trusses, is uncommon in Manhattan for reasons having to do with the building types and occupancies we have here. Here’s a close-up where you can just make out the truss closest to me:

You never know until you see it.