Pristine

I’ve put up so many photos of badly-weathered steel that is seems only fair to put up this one. You’ll need to click on it to expand it to see it properly.

This is a roof spandrel beam on an office building downtown, uncovered for parapet reconstruction. There’s a column connection on the right and the rivet heads for a beam connection behind on the left. It’s clear in the picture, but it’s worth saying: this steel is in fantastic condition. The beam itself is unrusted – the square edges of the bottom flange are sharp and straight as a die – and the rivets heads are perfect. The red color is the original red-lead primer coat of paint, and the black is some kind of mastic that was probably applied as waterproofing.

The presence of waterproofing is not the reason this 95-year-old steel looks so good. A lot of the damaged steel we see was painted and waterproofed. It might be that the masonry of the wall veneer in front of the beam and the masonry of the parapet that was (and will be again) above were more solidly built than normal, but that’s unlikely. A lot of the damaged steel we see has been hidden within well-built masonry. This is a tall building near the river, so it’s certainly exposed to enough rain.

I suspect that the ornamental veneer of the parapet did a better than usual job of shedding water outward, so that the water didn’t soak into the masonry and then onto the steel. But that’s just a guess.