Building materials typically suffer damage when air humidity remains above what percentage?

Building materials are particularly susceptible to damage when air humidity remains above 60%. This threshold is significant because elevated humidity levels can lead to a variety of issues including mold growth, material degradation, and a compromised structural integrity of surfaces like drywall, wood, and insulation. When humidity exceeds 60%, materials can absorb moisture, leading to conditions favorable for mold spores to germinate, which not only damages the materials themselves but can also pose health risks for occupants. Maintaining indoor humidity levels below this percentage is critical in water damage restoration practices to safeguard the integrity of building materials and promote a healthy environment.