By Cass Jacoby.
It can be hard to conceptualize how air can damage a roof structure and insulation — it's just air! However, a big part of how sneaky air can be in creating issues for your roof is that you can’t see it. Air aids moisture, thousands of gasses, snow, rain, heat, dust and dirt.
It is important to ventilate your attic because air flow can minimize a myriad of problems. If your home lacks proper ventilation you may be at risk for mold, rotting decks, ice dams and increased home cooling costs. Air ventilation is critical to the performance of a roofing system and the interior comfort of a home, maintaining a cooler attic in the summer and a dryer attic in winter.
While it is tempting to assume that any and all ventilation is good ventilation, it would be a mistake to mix roof ventilation systems. Each vent type (box, slant-back and turbine) is designed to move air flow differently through the attic. Mixing vents may cause a short circuit in the system, negatively affecting the air flow passage which can lead to weather infiltration and increased energy bills. However, this does not mean you can’t add to the existing ventilation system. You can increase the intake or exhaust in the attic by adding additional vents of the same type. You cannot over ventilate the attic space as long as you adhere to the 1:300 rule and meet the minimum requirements for a balanced system - 50% intake and 50% exhaust.
The secret to an effective ventilation system is to create a balance. This allows hot air to escape and your roof to breathe by ensuring the air flow has a steady way to enter (intake) and exit (exhaust) the roof. You can prolong the life of your roof by properly installing something like the Quarrix StormStop Ridge Vent on the ridge and hip of your roof, which can keep attics cool and dry by creating a well-balanced air flow that allows your attic to breathe. Ask your contractor for advice on the best practices to use to maintain good ventilation this balance.
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Cass works as a reporter/writer for RoofersCoffeeShop and AskARoofer. When she isn’t writing about roofs, she is writing about movies for her master's degree and dancing with her plants.