Why Too Much Indoor Humidity Is Bad for Your Roof

It’s common knowledge that exposure to the elements will eventually take its toll on your exterior over time. What’s less well-known is the problems that high humidity levels—specifically warm, humid air that can’t exit your roof or attic—can do to your roof. 

Here’s an overview of some of the issues caused by high indoor humidity levels: 

Mold and Mildew 

If it can’t exit your roof or attic, warm, humid air will condense into droplets on wood roof rafters, support beams, joists, and decking. Excess condensation is a problem because it creates a damp environment that’s the perfect breeding ground for mold and wood, which can slowly eat away the wooden components of your roof’s support. Not to mention they can easily affect other parts of your home if left unattended. 

Cracks in the Roof’s Structure 

Trapped heat in your roof can wooden parts of your roof’s structure to expand, creating cracks through which water can infiltrate your roof. 

Curling Shingles 

High temperatures and humidity levels in your attic can shorten your roof’s lifespan. If you see curling or faded shingles on your roof, you’ll need to replace them with new residential roofing shingles as soon as possible. 

How to Keep High Humidity Levels Under Control 

Your roof and attic should have enough air vents to allow warm, humid air to exit and fresh air from outside to enter. How much ventilation does your roof need? As a rule of thumb, there should be a square foot of net free area (NFA)—the area through which air can pass—every 300 square feet of floor area for attics with a vapor barrier.

Important note: Keep in mind that more ventilation isn’t necessarily better. That’s because installing too many air vents can disrupt indoor airflow. If you’re not sure if your roof has enough ventilation, it’s best to have a roofing contractor inspect your home. 

Looking for roofers near you? 

M & A Roof Home Improvement, a company with an A+ rating with the Better Business Bureau®, offers a wide range of professional roofing services, including roof repair and replacement services.  To request a free quote, call us at (757) 779-5244 or fill out this form. We serve homeowners in Virginia Beach and Norfolk as well as the surrounding VA communities.