Track 2: Materials over Time: Points of Change
Modern Materials: Challenges in the Details
Monday, September 24
10:30 AM - 12:00 PM
Location: BNCC- 101BG
Modern materials present unique challenges in terms of assessing performance and evaluating whether these materials can (and should) be repaired and conserved, or whether they need to be replaced. For example, some modern materials are inherently vulnerable to deterioration—or are no longer manufactured and thus, if too deteriorated to repair, are difficult to replace in kind. Modern wall systems tend to be less forgiving of water leakage than traditional masonry wall construction; responses to leakage in modern systems can be non-reversible or highly visible. Modern thin cladding present complex problems, such as hysteresis of thin stone veneer and resin panels. Issues of strength loss and anchorage deterioration are also of greater concern with modern thin claddings. The effects of material weathering may be considered desirable on traditional materials but is often less acceptable on highly machined materials typical of modern buildings.
However, not only modern materials require special consideration in preservation, but also the way in which these materials are detailed for use on modern buildings and structures—detailing that often makes it difficult to develop an effective yet non-intrusive repair. For example, the relatively flat roofs prevalent on many modern structures provide little room for incorporation of sufficient slope to drain, and greater slope (if possible to incorporate) is difficult to conceal behind shallow or non-existent parapets. Steel and glass assemblies typically do not have sufficient tolerance to permit additional separation of the metal and glass components if needed in a repair design. Modern curtain walls with single glazing do not necessarily accommodate thermal improvements without significant modification. Thin veneer claddings often rely on highly repetitious anchorage systems such as kerf anchors; failure of one anchor will likely be repeated, as the detail appears multiple times across a facade.
This presentation will illustrate a variety of materials and details used in modern buildings, the problems presented by these assemblies, and repair solutions developed. Examples will include various iconic modern historic structures that the presenter and her colleagues have investigated in recent years, and will also be drawn from the less iconic (but equally challenging) case studies presented in the monthly “Failures” column co-authored for the Construction Specifier by Deborah Slaton and David Patterson of WJE for the past two decades. The APT “Consensus Principles for Practice on Renewing Modernism” will be discussed with reference to the examples presented. This presentation is intended as a companion piece to the presentation entitled, “Modern Materials: Assessment and Repair,” presented by the author at the symposium, Renewing Modernism: Emerging for Practice, at the APT annual conference in Kansas City in November 2015.
- Understand the range of materials used in modern buildings and the challenges presented in repairing these materials.
- Understand some of the detailing issues presented by modern building construction.
- Describe some solutions developed to address problems with modern materials and details.
- Apply the APT Consensus Principles for Practice on Renewing Modernism to relevant examples.