Critique of Milstein Hall: Nonstructural failure

Jonathan Ochshorn

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Nonstructural failure contents: 1. introduction | 2. water and thermal control | 3. sloppy or dysfunctional details | 4. dangerous details | 5. maintenance issues | 6. cracks

3. Sloppy or dysfunctional details

I have not speculated about the reasons for detailing failures in Milstein Hall (some general notions about architects' attitudes towards detailing can be found in Designing Building Failures). It should be emphasized that such problems are not inevitable, even in complex or peculiar buildings. There is, however, a higher probability that such design problems will occur when complex or peculiar buildings are produced and, for that reason, more attention must be paid in both the design and construction phases to avoid them. By analogy to "defensive driving" techniques employed to reduce automobile accidents, architects should always employ "defensive detailing" to reduce the likelihood of sloppy or dysfunctional details.

As buildings get more complex, more collisions of geometries and of materials can be expected; each potential collision must be investigated and resolved. Anticipating problems means understanding architecture as something in motion rather than as a fixed and static object — to think of buildings as objects to be inhabited rather than merely modeled or photographed. Everything moves: structures move under dead, live, and environmental loads; elements expand and contract due to thermal and moisture changes; while water, vapor, air, and heat flows make the building enclosure a virtual laboratory of physical and chemical changes. Defensive detailing simply means that the unanticipated must, instead, be anticipated.

Here is an example of defensive detailing (or lack thereof): Alarms were placed in some of the fire-barrier doors installed between Milstein and Sibley Hall — the idea was to have these alarm go off when doors were propped open for too long a period of time. Unfortunately, the alarms have been going off quite often, sometimes several times per day, and are easily confused with actual fire alarms. Occupants of the building, hearing these alarms go off routinely, no longer respond to them: this places everyone in danger, since a real fire alarm may no longer be understood as a serious call for evacuation.

What follows is not an all-inclusive list of sloppy or dysfunctional details. I have not been given official access to such information, so the items that follow are based only on my random observations of the building:

  1. Curtain wall cover plate details were worked out in the field, having never been adequately documented for the two visually similar but internally different conditions at the south-east and south-west intersections of the ground-level sloped glazing. The glazing at the south-west corner enclosing the auditorium is much thicker than the glazing at the south-west corner enclosing the entry lobby due to the greater need for acoustic resistance at the auditorium. Workers could be seen puzzling over the detail at the south-east corner, instructed to provide a few alternative metal plate mock-ups on site, so that those in charge could decide which detail to actually use (Figure 1). While this does not necessarily lead to nonstructural failure, it does point to a lack of adequate attention paid to detailing, which certainly increases the likelihood of such failure.

    Milstein Hall glazing trim prototypes

    Figure 1. A worker creates several trim prototypes for the glazing intersection at the lobby of Milstein Hall. Image screen-captured from Milstein Hall construction video by J. Ochshorn (Part 8 — curtain wall).

  2. Milstein Hall's roof beams and corrugated steel deck are exposed in the upper level studio space, but the floor structure is mostly covered up by stamped aluminum soffit panels. Where a rectangular hole is punched in this floor structure to accommodate a stair to/from the lobby below, glass fascia panels were installed, revealing parts of the steel structure that would otherwise be hidden. The spaces between these glass panels were not sealed or covered with vertical mullions, however, thereby providing numerous access points for moths and other insects or arachnids (Figure 2). They get in, but cannot find their way out, and so this glazed area has inadvertently become something of an entomological display case.

    Figure 2. Video (1 minute long) by J. Ochshorn shows moths (and other creatures) trapped within the glass "display case" in Milstein Hall (video shot July, 2012; can also be viewed directly on YouTube).

  3. There are many ways to characterize nonstructural building failure. One type of nonstructural failure comes about because of the difference between drawing or modeling something and actually building something. It may seem obvious that representation and reality are different, yet this difference is often ignored when designing buildings. Many products are manufactured as extrusions (aluminum sections, for example), or are rolled or otherwise molded into straight elements. In some cases, such elements can be bent (drywall and steel rolled sections, for example), but in many cases, building components manufactured in straight sections cannot easily be reconfigured into curved geometries. Even intersections of straight elements that are not at right angles can cause problems.

    Both of these issues appear in Milstein Hall. The curved glass guard rail for the stair linking the lobby to the upper level studios is one example where ad hoc and sloppy construction details resulted from the use of products — designed for straight lines — in curved applications (Figure 3). The enclosure separating the upper level studios from the auditorium below is an example of a sloppy and seemingly ad hoc transition where straight elements are joined (Figure 4). It's not completely clear why this detail presented such complications.

    Figure 3. Video (2 minutes long) shows curved guard rail detailed with cheesy sealant joints and glued-on aluminum strips instead of with difficult-to-manufacture curved gaskets, resulting in sloppy and ad hoc details for the curved sections (video shot January, 2012; can also be viewed directly on YouTube).

    sloppy detailing or construction at Milstein Hall aluminum fascia trim

    Figure 4. The probability of sloppy intersections, even of straight aluminum elements, increases when unusual or nonstandard angles are specified (screen-captured from video by J. Ochshorn, January 2012).

  4. Bowing of wood floor boards occurs due to differential expansion or contraction on either face of the boards. If the wood grain is not perfectly consistent (such perfection found only in the finest quarter-sawn lumber), moisture will have a different effect on the two faces, as these faces will differ in the degree to which their grain is oriented radially rather than tangentially — wood expands and contracts more tangentially than radially. It is possible that, even with the wood grain perfectly consistent throughout the cross section, moisture will be present to a greater or lesser degree on the bottom faces of the boards that are in closer contact with moisture in the underlying concrete slab. Since wood expands or contracts depending on its moisture content, which is in turn sensitive to atmospheric conditions, any such exposure to moisture may cause bowing of the boards. Furthermore, this effect is more pronounced with wide boards such as the ash planks specified for Milstein Hall (Figure 5), since the bowing occurs over a greater cross-sectional dimension.

    bowing of wood floor boards in Milstein Hall

    Figure 5. Wide ash floor boards have bowed in the Milstein Hall upper-level "studio lounge" (image by J. Ochshorn, Jan. 2012).

  5. Acoustic problems due to hard surfaces in the upper level studio space have been partly remediated through added acoustic ceiling panels; even so, the studio space remains difficult to use for critiques because there are no separated critique rooms; the crit room below the concrete dome is an acoustical joke, or perhaps a nightmare. Aside from the inappropriately large reverberation time owing to the hard concrete surfaces of both floor and ceiling, the doubly-curved geometry of the ceiling creates unusual patterns of unwanted reflected sound including effects reminiscent of whispering galleries (Figure 6).

    Milstein Hall crit room acoustics

    Figure 6. Milstein Hall crit room acoustic problems are created by the doubly-curved shape of the cast-concrete ceiling. Conversations at point "A" can be heard at point "B," so that multiple critiques in the space — as envisioned by the architects — are difficult to actually implement.

    Auditorium acoustics are mediated by sound-insulation above perforated stamped aluminum panels on the ceiling. Outdoor noises are kept out by thick acoustically-treated glazing. However, all of this attention to the attenuation of sound is compromised by the auditorium's "weakest link": the glass door at the lowest level provides no acoustic isolation from corridor noises; the same is true with the glass doors linking the auditorium to the studio floor above (Figure 7). A new glass door between the auditorium and the adjacent crit room, mandated when a NYS hearing board ruled that the single exit designed for the crit room was illegal, makes it impossible to use both rooms simultaneously: any noise generated in either the crit room or the auditorium is heard in the adjacent space.

    Figure 7. Video (1 minute long) by J. Ochshorn shows acoustically-challenged auditorium doors in Milstein Hall (video shot August, 2013; can also be viewed directly on YouTube).

  6. Lighting failures: it is impossible to use digital projection facing and adjacent to the west wall of the studio on clear days in late afternoon or early evening because of the western sun; there have also been reported glare issues from skylights, as well as excessive lighting levels at night.1 In general, lighting systems seem to be experiencing problems: studio lighting was turned on at all times, even when the studio was unoccupied (I've heard, but cannot verify, that motion sensors were not working properly); and recessed soffit light fixtures above the outdoor, covered space between Milstein and Sibley Halls were not useable at all (I asked why these lights were not turned on during an August 2013 reception that took place in this dark covered space and was told that turning these lights on was, inexplicably, not possible — see video, Figure 8).

    Figure 8. Video (1 minute long) by J. Ochshorn shows various problems with indoor and outdoor lighting (video shot August, 2013; can also be viewed directly on YouTube).

  7. There have been a couple of instances of unintended concrete staining, or mottling, on Milstein Hall's walls and floor slabs. In the case of the floor slabs, a red stain appeared in the Crit room, possibly caused by wooden protection boards that were placed over the slab before it was fully cured. In the case of exposed concrete walls, also along the Crit room as well as the auditorium, mottling or staining apparently resulted from the combination of two form release agents that were applied to wooden forms (Figure 9). In some cases (not necessarily, but quite possibly, in this instance), the specification of LEED-friendly, but relatively untested, products causes such unintended problems.

    Figure 9. Video (1-1/2 minutes long) by J. Ochshorn shows staining or mottling of concrete surfaces (video shot April 5, 2010; can also be viewed directly on YouTube).

  8. An interior metal curtain wall veneer has started peeling (Figure 10) on the second-floor studio level, adjacent to the exterior stair.

    Metal curtain wall veneer peeling on 2nd floor of Milstein Hall, Cornell

    Figure 10. This delamination was pointed out to me by an architecture student. Photo by J. Ochshorn Feb. 6, 2015.

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Nonstructural failure contents: 1. introduction | 2. water and thermal control | 3. sloppy or dysfunctional details | 4. dangerous details | 5. maintenance issues | 6. cracks

Notes

1 See "Cornell's Sustainable Vision for Milstein Hall" (note 4): online, accessed Aug. 16, 2013.