By Russell M. Sanders, AIA
The Federal Emergency Management Agency (FEMA) recommends that “building owners have a vulnerability assessment performed by a qualified architectural and engineering team.”* As building envelope materials deteriorate over time, they become increasingly susceptible to failure. Many existing facilities lack adequate strength to resist current design level winds, whether due to age, design flaws, material failure, or improper construction. By retaining a design professional to perform a vulnerability assessment, owners can prioritize areas that need to be strengthened or replaced. Proactively addressing building envelope weaknesses before a natural disaster strikes can prevent the expense and disruption of emergency stabilization and rehabilitation.
Problem: Weak curtain walls, masonry, or veneers
Solution: Remediate components incapable of withstanding wind design loads.
Problem: Aging or deteriorated windows and seals
Solution: Replace gaskets and sealants, or replace window assembly.
Problem: Hurricane zone building with standard glazing
Solution: Replace with impact-resistant glazing, or install hurricane shutters.
Problem: Aggregate roof surfacing, lightweight pavers, or cementitious-coated insulation boards
Solution: If building is in a hurricane zone, remove down to the deck and replace.
Problem: Unanchored rooftop equipment
Solution: Screw or bolt equipment to curbs. Add latches to access panels.
Problem: Weak roof structure
Solution: When reroofing, strengthen deck attachment and support structure.
Problem: Poor edge flashing or coping attachment
Solution: Attach vertical flanges with face-mounted fasteners.
Problem: Single roof membrane system
Solution: For hurricane-prone areas, incorporate a secondary membrane when reroofing.
Problem: Failed precast concrete connections
Solution: Augment or replace connections to resist wind loads.
Problem: Low parapet wall on low-slope roof
Solution: Raise parapet to at least three feet and secure base flashing.
Problem: Old sectional or rolling doors
Solution: Strengthen weak doors and tracks or replace.
*“Making Critical Facilities Safe from High Winds,” Design Guide for Improving Critical Facility Safety from Flooding and High Winds: Providing Protection to People and Buildings, Federal Emergency Management Agency, 2007.
Sanders is executive vice poresident and senior director of Technical Services with Hoffmann Architects, Inc., an architecture and engineering firm specializing in the rehabilitation of building exteriors. He is also the company’s resident expert on building envelope insurance claims, experienced in evaluating and resolving distress related to hurricanes, tornados, snowstorms, hail storms, fires, and other disasters for owners, insurers, and their representatives.
