Water Damage Restoration Technician (WRT) Certification Practice Test

Above what percentage of relative humidity do many building materials begin to absorb excess water vapor and suffer damage?

1. 60%

2. 70%

3. 80%

4. 90%

The correct answer is: 70%

Many building materials, such as drywall, wood, and insulation, are designed to function optimally within a certain range of humidity. When the relative humidity exceeds 70%, these materials start to absorb excess water vapor from the air. This absorption can lead to various forms of damage, including warping, mold growth, and degradation of structural integrity. At or above this threshold, the materials can no longer remain in a balanced moisture content state. They begin to experience physical changes that can compromise their durability and performance. It's important for professionals in water damage restoration to monitor and manage humidity levels in affected areas to prevent extensive damage. Understanding this threshold helps technicians implement effective drying protocols and ensure that moisture is controlled to maintain the integrity of building materials during restoration efforts.