I have been looking for a picture of this. Many people put screening on their vents to keep squirrels from chewing on the lead, but one has to be careful what kind of screen is used. Metals can react with each other and cause corrosion. This is why you will never see a lead flashing on a metal roof, the lead and the metal react and corrode.
Here is a picture of a corroded screen on a vent. Its not the correct screen material to use.
Critter Quitters are a far better choice to protect your vents. They will never corrode, they dont react with the lead, and the are resistant to chewing. They also will last a very long time. Get some today, homdedpot.com or amazon.
Screen on Vents Causes Corrosion
