Concrete spalling in aging parking garages drops chunks on cars but inspection cycles are 5+ years

Post-tensioned concrete parking garages built in the 1970s-1990s are experiencing accelerating spalling — chunks of concrete delaminating from ceilings and falling onto parked vehicles — because road salt and water infiltration corrode the embedded steel tendons. A single fallen concrete piece can total a car's hood or windshield, and garages in northern climates see 3-5 incidents per winter season. Yet most municipalities require structural inspections only every 5-10 years, and garage owners patch visible damage cosmetically with epoxy rather than addressing the systemic tendon corrosion underneath. The structural engineering required to properly assess post-tensioned systems is specialized and expensive ($15-25 per square foot for full repair), so owners defer until a catastrophic event forces action — as happened in the 2023 New York City garage collapse that killed one person.