This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Every account of Fallingwater's construction agrees on the bare mechanics: Wright's staff engineer, Mendel Glickman, designed the cantilevered concrete floor slabs that carry the house out over Bear Run, and the reinforcing steel actually poured into those slabs was substantially more than Glickman had specified. What the accounts disagree on, and disagree on in ways that have never been fully settled, is who ordered the extra steel, and what that decision says about Wright, about Kaufmann, and about how much either man trusted the other. What is clear is the sequence of the falling-out. Uneasy about Wright's comparatively limited experience with reinforced concrete at this scale, Kaufmann had the cantilever design reviewed by outside consulting engineers, and he did this without first telling Wright. When the review came back recommending significantly more reinforcement than Wright had drawn, Wright did not treat it as useful engineering feedback. He treated it as an accusation. He demanded his drawings back and indicated he was prepared to withdraw from the project entirely, and by at least one telling Kaufmann backed down enough that the critical report itself was set aside rather than acted on openly. And yet the steel went in anyway, before the concrete was poured, doubled by most tellings, though the record is genuinely split on whose hand did it: some accounts have the contractor quietly increasing the reinforcement on his own initiative, at his own cost, without making a public issue of it; others have Kaufmann's own consulting engineers redrawing Wright's rebar plans directly, overriding him a second time after the report itself had ostensibly been shelved. Both versions agree that Wright, on eventually learning what had happened, was furious, writing to Kaufmann that he had put more into the house than any client had a right to expect, and that without Kaufmann's confidence the whole project could go to hell. Read one way, this is a story about a great architect's ego getting in the way of sound engineering: the reinforcement, whoever added it, may well be a meaningful part of why the house has never structurally failed, even as its longest cantilever crept downward by inches over the following decades, requiring a major post-tensioning repair in 2002 to arrest further sagging. Read another way, it is a story about a patron who could not quite let his architect alone, who went behind his back not once but effectively twice, and who therefore has at least as much claim on the credit, or the blame, as the men who actually poured the concrete. The atlas does not resolve which reading is correct; Kaufmann's own page carries the dissent, with Wright's own contemporaneous fury standing as the named challenge to any tidy story in which the outside engineers were simply, uncomplicatedly right.