brick vs. steel in the monadnock
May 24, 2019 § Leave a comment
This one again…The Monadnock continues to surprise. Elsewhere I’ve written about John Root’s towering mass of brick as a hybrid structure–a steel frame trapped within a brick building–and this past weekend it was again the subject of much discussion and many questions during a lecture to the Chicago Architecture Center’s new docent class (always a favorite date on my calendar).
Part of the building’s mythology involves Root’s minimalist detailing. Its history includes two design campaigns–one in the mid-1880s that produced a fairly standard set of elevations similar in some ways to the Home Insurance’s facades, and then a rush to redesign and actually build the structure in 1890-91. Correspondence during the latter phase between Root and the Brooks Brothers, through their Chicago agent Owen Aldis, discusses the building’s lack of ornament directly, including this classic rationale:
… So tall and narrow a building must have some ornament in so conspicuous a situation… [but] projections mean dirt, nor do they add strength to the building … one great nuisance is the lodgment of pigeons and sparrows
quoted in Donald Hoffmann, “John Root’s Monadnock Building,” Journal of the Society of Architectural Historians, Vol. 26, No. 4 (Dec., 1967). 269-177.
Pigeons may have influenced Root’s detailing, or–as Hoffman suggests–it may be that he was inspired by Egyptian papyrus plants. But none of the correspondence gets to the Monadnock’s really fundamental question: with buildings like the Tacoma (Holabird and Roche, ….) already pioneering the idea of a lightweight, terra cotta and glass skin, why make the apparently retrograde choice of massive, light-blocking masonry walls for the building’s exterior?
This choice is often attributed to the Brooks’ inherent conservatism–the assumption is that they were concerned about a new-fangled technology like steel, and wanted the reassurance of time-tested masonry for the majority of the building’s structure. I’ve suggested that rationale myself, and it makes for a clean narrative–the new, still somewhat untried structural system on the inside, being braced and assisted by the last great set of bearing masonry walls (or, as you can see in the model above, piers) to support one of the city’s skyscrapers.
Well, some digging on another question after the lecture turned up an article in the Chicago Tribune that provides another, more cogent reason for the choice of brick. The Brookses seem to have been fine with the structural capabilities of steel, but their choice of brick had more to do with building fires than building structures:
Tho contracts for this work are already let and call for a structure with a core of steel and walls of brick and terra cotta. The Boston people say that they have seen granite crumble to dust under the influence or fire, and that nothing but material fire-tried and proven by fire shall enter“Another Sky-Scraper: The Brooks Estate Will Put Up an Enormous Office Building.” Chicago Daily Tribune, Apr. 3, 1890. 1.
into the construction of the new block.
This makes sense. Boston suffered a devastating fire in 1872, which destroyed buildings of timber and stone, would have been on the Brooks’ mind, but closer to home the brothers had suffered the loss of the Grannis Block, a Burnham and Root building constructed in 1881, sold to the brothers in 1884, and promptly consumed by fire in 1885. The building’s timber floors were destroyed, but its pressed-brick front wall survived, as did its interior iron columns, protected by terra cotta fireproofing. That formula, adjusted to take advantage of steel and supplemented by terra cotta floor arches instead of timber beams, was precisely that of the Monadnock. If their preference for brick as a fireproof material extended to even the slightest suspicions regarding the light terra cotta skin of the Tacoma, it might also explain somewhat the lack of ornament–while both materials proved themselves to be fire-resistant over the next decade, brick certainly had a longer track record.
All of which is to say that the Monadnock, rather than representing a definitive type or approach, was conceived at the very cusp of several developments in structure, fireproofing, wind bracing, and real estate. It continues to be one of the richest and most perplexing of Chicago’s early skyscrapers.