Chimneys are notorious for leaking, and the culprit is almost always the sheet metal flashings. Just ask any roofer. But it doesn’t take an expert to spot problems simply look for water stained ceilings or other telltale signs of leaking in the
vicinity of your chimney. You’ll want to install
new chimney flashing if it’s missing, rusted
through, falling out or completely
covered with roofing tar.