Challenges of modern materials: assessment and repair

Abstract

ABSTRACTModern materials present unique challenges in terms of assessing performance and evaluating whether these materials can be repaired, restored, and conserved, or whether they need to be replaced – based on criteria including inherent significance and integrity, anticipated performance, durability, resiliency, and potential for continued use. Some specific issues encountered with modern materials include questions related to weathering, lack of redundancy, and the use of innovative but inherently non-durable materials and assemblies. The effects of material weathering (patina) may be considered desirable on handcrafted materials but is often less acceptable on highly machined materials typical of modern buildings. While the weathered appearance of traditional materials may be considered tolerable or even desirable, some modern buildings may demand frequent treatment to achieve a consistently new appearance. The inherent lack of redundancy in modern thin claddings such as thin stone veneer and resin panels, as well as glass and metal curtain wall systems, presents complex problems that were not historically of concern with traditional materials. For example, modern materials and systems are less forgiving of water leakage than traditional masonry wall construction; issues of strength loss and anchorage deterioration are of greater concern with modern thin claddings. Finally, some modern materials and systems have a limited life span and are far more demanding in terms of cyclical maintenance than traditional materials, while changes in production have rendered some materials obsolete and difficult or impossible to duplicate exactly if replacement is required. Innovative materials also present particular challenges if they have not performed well over time or contain hazardous components. However, if the materials are significant and character-defining, they will likely warrant preservation based on technical uniqueness and in order to preserve the original architectural intent. This article examines a range of modern materials and their characteristics in light of these issues and criteria, illustrated with examples from recent projects involving thin stone and resin cladding panels, glazing systems, and coatings and sealants, among others, with comparison to traditional materials where appropriate. The article also seeks to inform the development of conceptual guidelines for the assessment and repair, restoration, and conservation of modern materials.