What is Drywall and Why is it Vulnerable to Moisture?

Drywall, also known as wallboard or gypsum board, is a common building material used in the construction of interior walls and ceilings. It is typically composed of a plaster core sandwiched between two paper liners, providing a smooth and paintable surface. However, drywall is susceptible to moisture damage, which can compromise its structural integrity and lead to mold growth and other problems.

Common Sources of Moisture

After construction, several factors can contribute to moisture exposure and subsequent damage to drywall:

• Leaks: Moisture from plumbing leaks, roof leaks, or other sources can penetrate drywall, causing it to soften and deteriorate.
• Condensation: Changes in temperature and humidity can lead to condensation on drywall surfaces, especially in areas with poor ventilation.
• Flooding: Water from flooding events can saturate drywall, causing significant damage.
• High humidity: Extended periods of high humidity can cause drywall to absorb moisture, leading to swelling and warping.

What is a Normal Moisture Reading for Drywall?

Under normal conditions, the moisture content of drywall should be between 5-12%. However, readings above 15% indicate excessive moisture, which can lead to damage.

Prevention and Mitigation Strategies

To protect drywall from moisture damage after construction, several strategies should be implemented:

• Preventative Measures:
  • Ensure proper ventilation in all areas of the building to reduce condensation.
  • Use moisture-resistant drywall in areas prone to moisture, such as bathrooms and kitchens.
  • Seal joints and edges of drywall with moisture-resistant sealants or tape.
  • Install vapor barriers to prevent moisture from permeating through walls and ceilings.
• Mitigation Measures:
  • Address leaks and sources of moisture promptly to prevent further damage.
  • Monitor humidity levels and use dehumidifiers to control moisture in the air.
  • Repair damaged drywall sections immediately to prevent further moisture penetration.

By following these measures, you can effectively protect drywall from moisture damage, ensuring its longevity and maintaining a healthy and habitable interior environment.