Deflection, Seismic Drift, Panel Walls, and Control Layers

This presentation initially took place at IIBEC's 2022 International Convention and Trade Show in Orlando, Florida.

Building structures are not entirely static, as they are designed to deflect and move under various loading conditions such as live loads, wind loads, and seismic loads. Some movement locations such as building expansion joints, cladding expansion joints, and curtainwall stack joints are typically well defined by the architectural design of the building. In many instances, however, the movement of a building structure occurs at more subtle interface and transition conditions that are not always clearly defined architecturally. Determining the location of this movement can become increasingly complex with unitized and panelized wall systems in seismic areas that have airtightness requirements. This presentation provides background on how building structures move and the impact that movement has on enclosure systems and their geometry. This presentation also suggests design approaches for identifying the building movement locations to address control layer continuity.

Brad Carmichael, PE, CPHC
4EA Building Science | Seattle, WA

Brad Carmichael has been consulting on building enclosures throughout North America for more than 15 years; his work has included complex new construction and rehabilitation projects. He is passionate about good design and the role it can play in social and environmental stewardship. He believes that durable and efficient building enclosures are critical for a built environment that is low consumption and long lasting.