In The Details

by Don Friedman on April 28, 2017

God is in the details – Mies van der Rohe

The Devil is in the details – Anonymous

A topic that I find interesting in general, and critical professionally, is how engineers make decisions with incomplete information. This comes up in all types of engineering design discussion, from our alteration and repair niche to oil-rig design, but it’s more pertinent in terms of building investigation.

The picture above was taken in Sæmundur í Sparifötunum, the saloon in the Kex Hotel (in Reykjavík) that is housed in a converted industrial bakery. Knowing that much and nothing more, it’s a good bet that the building is constructed of reinforced concrete. Both steel and cement have to be imported to Iceland, making both relatively expensive, but the logistics of steel hauling make it more expensive and difficult to get. Also, from about 1900 onwards, multiple-story industrial buildings in most western countries have been built in reinforced concrete.

If I come at the question from the other end, what do the visible portions of structure in this occupied and finished building tell me? There’s a column with an asymmetrical octagonal section, and the beams coming in to it have haunches. That could all be fireproofing or cover, of course: it could be a steel column with a wide-flange or tubular section encased in concrete; the haunches could be concrete encasing steel gusset plates. But the geometry is wrong. There’s no theoretical steel core for that column that would warrant the octagon for encasement; and steel gusset plates would have a much sharper diagonal than those haunches.

So a contextual analysis of the situation leads to a conclusion that the building is likely concrete and an engineering review of the visible structure separately leads to a conclusion that the building is likely concrete. I don’t have any solid information, but I’m pretty certain that this is concrete. If this were a project*, I’d be comfortable asking for a couple of probes to confirm the concrete assumption and heading straight into design.

* It was, actually, dinner.

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