We had a good question come in the other day. Someone wanted to know how much flashing was needed left on the vent for our shields to work. As long as there is a least an inch of lead left above the roof line our shields will work. But if its been chewed all the way to the roof line, or if the chewed area is at the roof line, you will need to reflash. This is a major leak because now water cascading down the roof is entering like a waterfall. So if you have that situation, reflash ASAP and order some Critterquitters to keep it from happening again.