Facades / Cladding
The great American architect, Louis Kahn, said that before designing a brick building, he’d ask the brick, “What do you want to be?” The brick would answer, “I want to be an arch.”
Indeed, in most of Kahn’s buildings, and from Roman times until fairly recently, brick did get to be an arch. But during the past century, brick has rarely gotten to be an arch, or even a solid wall.
Instead, brick gets to be supported on a steel shelf angle, sharing its space with flashing, metal anchors, and weep vents. Often, brick barely gets to be a brick – when it’s glazed or cored, or used as a single 3 – 5/8″ thick veneer.
NYC has thousands of buildings, in a variety of architectural styles, constructed over a span of two centuries, in which brick, stone, terra cotta, metal, glass, and concrete have been used alongside one another. (Lou Kahn was also a fan of exposed concrete.) These materials have different physical characteristics: strengths, moduli of elasticity, coefficients of thermal expansion, and porosities. They expand, contract, and move differently, but must be fastened together to form an assembly that resists imposed loads while keeping air and water out.
Inevitably, these systems succumb to the effects of the NYC environment – a rare combination of freeze / thaw cycling and a saline coastal environment.
The spectrum of solutions runs from total replacement to cautious observation. The large middle ground between these two extremes involves a variety of repair materials and techniques. As practitioners of the art and science of exterior restoration, it’s our role to select the optimum path.