Ridge Vents Preventing Airflow

Hi John, 

 

Below is what our roofing expert John Kenney with Cotney Consulting Grouphad to say in response to your 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.

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Below is what our roofing expert Luis with Wagner Roofing had to say in response to your question:

Based on the image provided, the ridge vent caps appear to have been improperly installed, as the fasteners may be driven too tightly. Over-driven nails can compress the vent material, which can restrict airflow and reduce the effectiveness of the ridge vent system.

The attic temperatures you’re describing, especially exceeding 140°F on hot days, suggest that the current ventilation may not be performing adequately. In situations like this, it is important to evaluate the attic ventilation system to determine the most effective solution.

I would recommend a professional assessment to identify the best ventilation approach for your attic. In many cases, upgrading to a rigid plastic ridge vent designed for improved airflow, combined with the installation of Lomanco powered ventilation, can significantly enhance air circulation, and help reduce attic temperatures. Improved ventilation can also help alleviate excess heat buildup that may be contributing to shingle distress and increased strain on the HVAC system.

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