Historic Structural Detail: Assembly Required

by Don Friedman on March 22, 2017

It’s been a while since I’ve done one of these posts, possibly because my attention has wandered to more fertile fields of criticism. In any case, the picture above is a nice illustration of just how much cast-iron facades were kits to be assembled. (Note that there’s some flash burn on the left side of the image. As explained below, this picture was taken in a very cramped space in the dark, so it’s inevitable that the flash would reflect back in the lens unevenly.)

This is the inside of a cornice on a cast-iron facade. The brick on the right is fireproofing back-up, as can be seen from how sloppily it’s laid up. A structural brick wall is flat, more or less. The thing past the brick is a structural cast-iron column, and the visible bolt is part of a connection. That beautifully curved bracket is cast-iron, holding up the cast-iron cornice fascia on the left. I absolutely love the inside-out view of the dentil band on the left.

The iron is all in good condition, which is not surprising. Cast iron resists rust very well, because the surface rust (the reason that it’s all brown) adheres to the base metal and protects everything below from oxidation. The brick looks terrible, in part because the presence of the iron means that these brick joints have never been repointed. And the inside of the cornice is, unsurprisingly, filthy.

The big iron works churned out standardized columns and brackets and beams, and it was up to the architects and builders to find different combinations of assembly to make the buildings look different. It worked to some degree, but the overall effect is something like a row of brownstones: the small detail differences fade compared to the overall similarity:

Greene Street cast-iron facades courtesy of Andreas Praefcke.

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