How Proper Ventilation Extends The Life Of Your Roof

No house comes with a parts manual. What are hip jacks? Cripple rafters? What is roof ventilation? You can get away with not knowing the structural wood members of your Massachusetts home’s roof, but you will benefit by learning about proper roof ventilation. 

Basic Physics

No need to dust off your high school science books. Your roof works using basic physics; air comes in at the eaves — through soffit vents — and exits your roof through either ridge vents or gable vents. That’s it! A current of air at the same temperature and moisture level as outside air should always move through your attic. 

A lot of homeowners misunderstand attic ventilation and insulation. After all, your attic floor is insulated. Sometimes the underside of sheathing is insulated. That insulation keeps your interior living space cozy and comfortable. It separates untreated attic air from treated interior air. 

Air moving through the attic prevents:

  • Mold and mildew
  • Wood rot and dampness
  • An inviting home for insects and rodents

Soffit vents allow air to rise by convection to ridge or gable vents. Air circulation should never stop. Rafter ends should never be blocked by insulation. 

Roof Ventilation

When you get a complete roof replacement, your roofer will assess roof ventilation and recommend improvements to its airflow. That could mean a powered gable vent, bigger ridge vents, or soffit baffles. 

Diagnosing poor ventilation is easy. You can safely climb into your attic with a flashlight. What does the underside of the sheathing look like? Can you see water stains or mold on any structural members? Is the air musty or stagnant? 

A cheap, fast, and easy test is to light an incense stick or smoke stick. A trail of thin, wispy smoke rising from the stick and exiting at the ridge (top) of your roof is good. The smoke should not merely swirl and hover at the joists, the horizontal timbers forming your home interior’s ceiling. 


Your roofer can help solve poor attic ventilation issues. Connect with your residential roofer and arrange a site visit. The solution could be improved gable vents, clearing soffit vents, or changing the ridge vents for larger ones. Couto Construction in Southeastern Massachusetts, Cape Cod, and Rhode Island is your local, trustworthy residential roofer. Contact us today to see how we can solve all your roofing riddles.