Q&A – Ridge vents and airflow

Looking at their roofline, this homeowner had some concerns. Naturally, they turned to the experts at AskARoofer.com!

When John, a Maryland homeowner, was looking at their roof, they noticed something odd. This is what they shared: 

I’m reaching out with a quick question about my roof’s ridge vent caps. I’ve attached a photo for reference. Can you please take a look and let me know if the nails appear to be driven down too far? I’m concerned this may be compressing the mesh and restricting airflow through the ridge vent. I’m asking because not only am I seeing issues in the shingles, but my attic temperatures during the summer are exceeding 140°F on 95°F days. I believe this excessive heat is overwhelming my HVAC system to the point where it cannot cool the upstairs below 76°F on those days.

And this is what our roofing expert John Kenney with Cotney Consulting Group had to say in response to the picture and question:

John, those nails do appear to be overdriven, which can compress the ridge vent and restrict airflow. From your photo, the cap shingles look tightly pinched against the vent material, leaving little to no expansion space. A properly installed ridge vent should allow air to flow freely through the mesh or baffle system beneath the ridge caps. When the fasteners are driven too far, the vent can lose its open channel, significantly reducing exhaust airflow.

Your attic temperatures confirm the issue. On a 95°F Day, a well-ventilated attic should typically stay around 110–120°F. Readings over 140°F suggest the hot air is being trapped, likely due to a combination of restricted ridge venting and possibly inadequate intake ventilation at the soffits.

I’d recommend having a qualified roofing professional remove a few ridge caps for inspection. If the vent is indeed compressed or misaligned, it may need to be replaced or reinstalled using the manufacturer’s specified fastener depth and spacing. Also, confirm that your soffit vents are open and unobstructed; both the intake and the exhaust vents are required for balanced airflow.

Continue the conversation in our Forum.