Examples Illustrated

I was at the annual SEAoNY conference yesterday – 9½ hours devoted to building codes – and it was, as expected, informative and interesting. Obviously, that’s not what I’m going to write about here. The conference was at Convene (a place where you can rent space for conferences) in a 1987 office building in midtown. I took this picture during the morning break, looking up at the underside of the third floor above us.

We’ve got a nice view, albeit fuzzy from the spray-on fireproofing, of standard office steel construction from not quite 40 years ago, AKA when I was just starting out in structural engineering. You’ve got the relentless grid of girders and filler beams, the underside of steel deck alternating ordinary composite deck and electrified deck with room for conduits, various hung items supported off fasteners into the deck and clamps on the beams, and two huge web penetrations in the girders. There’s the unused penetration left of the column, meant for pipes or conduits, and the penetration to the right of the column, currently housing a pretty big air duct.

All of this was meant to be covered, and is exposed because of the interior alteration when Convene took the space a few years ago. The unused penetration relates to the previous interior build-out. The vogue for “open ceilings” – i.e., letting the underside of the structure and the hung mechanicals all hang out, exposed to view – started well after 1987. Even the wood-slat sort-of-ceiling in the background is, to my eyes, preferable to the bumpy texture of the fireproofing. The fireproofing is fragile but is not exposed to impact in this layout, so that seems okay.

In the pre-BIM days of the 80s, there was often a mad rush by the structural engineers, late in the project, to provide slab and beam penetrations for unforeseen pipe, conduit, and duct. In my brief time working on new buildings back then, I encountered one steel-frame building where our company provided large penetrations at a regular spacing through every beam, leaving places where the mechanicals could later be put.