Short video today looking at the details on a roof, specifically addressing the vents and vent flanges and how they are secured to the roof. The most common method is to use nails to hold the flange down and secured to the roof decking. These nails have to be minimum 6d 1-1/2" long.
The nails used on this roof and featured in the video were nailed through the flange instead of using the holes created by the manufacturer. Nailing through a plastic flange like the one shown can crack or break the flange and make it susceptible for breaking and be free to move. When that occurs wind lifts it up and water can enter under the flange.
The most common defect I find on roofs are expose nail heads on penetration flanges, flashings, and shingles. These nail heads need to be covered with a roofing cement or roofing sealer to prevent water or moisture from causing the nail to rust. When this occurs, rust expands and creates a larger hole. Water can then migrate under the head and down the nail shank to the decking causing damage to the decking and attic structure. In severe cases, moisture will drip onto the insulation and ceiling drywall creating stains or damage.
This is very easy to correct by hiring a roofing contractor or if you are comfortable walking on a roof a caulking gun and some roofing cement will take care of the issue.
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