Many homes have at least three 1.5 to 3-inch PVC plumbing, furnace, radon, or other PVC vent pipes on their rooftops that are exposed to the elements. Pipey is one of those PVC vent pipes. His job is to safely release harmful gases and exhaust from your furnace, sewer, and radon lines. When He's doing his job, you're happy and healthy. Plumbing Roof Vent Cap
Squirrels, birds, and other small animals like him - a lot. They bring nesting materials, nuts, and other debris and drop it down into your sewer or furnace system through his open top. Even if the animals leave him alone, the wind and rain don't; any storm that comes his way drops rain, leaves, sticks, and all kinds of other debris down into your home.