Traditional Brick Masonry Detailing Meets Modern Cavity Wall Construction — A Difficult Marriage

Often architects and designers look to the past for historic precedents and inspiration on current projects, particularly that involving masonry construction. Although this practice can offer an improved aesthetic and a greater variety of interest in otherwise bland exteriors, they add construction complexity and do not always perform well. Traditional masonry wall systems were generally designed and constructed as mass walls, with little or no thought to water penetration, lateral load distribution, or other factors that impact the performance of modern cavity wall construction. Drainage provisions have taken the place of collar joints, steel structure has taken the place of thickened walls, flexural stresses control more than compressive stresses, and modern ties have replaced true headers. Lighter, thinner, taller...better? Maybe, but most definitely these changes have lead to increased consideration of performance and greater design complexity. With this transition to modern masonry wall construction, the integration of traditional details sometimes conflict with the realities of modern cavity wall construction. Architectural elements such as steep sloped roofs, roof base flashing, parapets, flat arches, conventional arches, dentils, water tables, and cornices do not always coordinate with flashing requirements, supporting structure, and expansion control requirements. This paper attempts to identify some critical considerations when traditional aesthetics are applied to modern cavity wall construction. Through exploration of these challenges and their eventual solutions, it is hoped that designers will consider the constructability of desired masonry detailing to help avoid serviceability problems in the future.