How Humidity Affects Your Roof: What St. Louis Homeowners Need to Know

St. Louis summers bring not just heat, but intense humidity that can take a real toll on your roof. High moisture levels lead to issues ranging from mold and mildew to warped or deteriorated roofing materials. Here’s what homeowners in the Greater St. Louis area should watch out for—and how to prevent long-term damage.

How Humidity Impacts Different Roofing Materials

• Asphalt shingles: When damp, shingles are more likely to grow algae or moss, which can darken your roof, clog gutters, and contribute to premature aging.
  
  
• Wood roofs: High humidity can cause warping, cracking, or decay in wood shakes and shingles.
  
  
• Underlayment and decking: Persistent moisture may weaken wood decking and compromise roofing underlayment integrity over time.
  
  

Signs Your Roof May Be Suffering

• Dark streaks or green patches on the roof surface
  
  
• Musty or moldy odors in the attic
  
  
• Staining or peeling paint along roof edges and fascia
  
  
• Higher cooling costs due to poor ventilation
  
  

Humidity and Ventilation Go Hand-in-Hand

A humid attic isn’t just uncomfortable—it’s a sign of poor ventilation, which can shorten the life of your roof and increase your energy bills. Proper airflow keeps shingles working properly and prevents moisture buildup.

Bade Tip:

Check your attic for signs of moisture at least twice per year (after winter and mid-summer). If it feels damp or musty, it’s time to call in a professional. Proper ventilation makes a big difference.

Call Bade Roofing Today

Bade Roofing has been working with homes throughout the Greater St. Louis area since 1954. Our experienced team can evaluate your roof’s ventilation and moisture control to ensure your home stays comfortable and protected.Call (314) 892‑1331 to schedule your inspection today.