The simplest leak to prove evidence on is a tile roof leak. If there is a skylight within 6 feet of the drip location odds are it’s the pan flashing on the skylight. It is simply put, the most common roof leak I encounter. No one is ever told it is something they need to maintain. Only when they meet me, due to the most unfortunate turn of events, do they learn the cause and maintenance requirement therein. One simple photo instils confidence in the home owner that I know what I’m talking about. Such was the case today in Vancouver. A single photo showing the wet 1×4 wood surrounding the skylight is proof that a dirty and compromised pan flashing was the cause of the leak. Now if only all leaks were that easy to find.