An old or damaged seal along the edge of a pop top shell will compromise the health of the roof tent it is trying to protect. This photo demonstrates the point. The gap in the rubber seal, which grew over time as the material shrunk, enabled water to travel past the seal when the pop top shell was in a closed position. Over a few seasons, the irreparable water damage to the surface of the canvas tent shows a direct correlation to the location of the gap in the seal above it. Look even closer and you can see the torn fabric. This rot in the canvas with an open tear will quickly grow with the slightest of pressure when it is this far gone. It is time to replace the rubber seal as well as the tent in this example.