SUNY Purchase College, Student Services Building
At Purchase College, a State University of New York (SUNY) campus, sustained winds contributed to catastrophic failure of the Student Services Building’s roof system. During a major rainstorm, the corner of the single-ply ethylene propylene diene monomer / terpolymer (EPDM) roof membrane sustained a 20-foot tear. As the storm continued, separation proliferated to encompass nearly 100% of the roof area.
The State University Construction Fund (SUCF) retained Hoffmann Architects + Engineers to evaluate the damage and to design and oversee roof replacement and rehabilitation. Our design professionals began by researching weather history data to determine why the storm led to such extensive roof failure. What we found was that wind speeds, while significant, were insufficient to cause complete blow-off. Our investigation revealed inadequate adhesion of roof assembly components, likely due to poor substrate preparation and inappropriate bonding compound selection.
Inattention to detail and incorrect installation caused what might have been an isolated problem to become a near-total roof failure. Hoffmann’s forensic investigation and research allowed us to piece together a likely chain of events, from initial membrane separation to complete roof system devastation. Failure to anchor drains, as well as the membrane itself, permitted enough air infiltration to delaminate and tear the membrane, at which point wind continued to lift remaining areas.
The extent and cause of damage now established, our architects and engineers moved on to designing and implementing the solution. We provided design documents for a more secure roofing system, with extensive detailing to minimize susceptibility of drains, flashings, and penetrations to wind uplift forces. SUCF retained Hoffmann Architects + Engineers to administer construction and provide field representation, to see that the solution was implemented as designed.