In a nutshell, a leak barrier is a product that works to prevent leaks caused by ice dams and wind-driven rain. An ice dam is a ridge of ice that forms on the edge of a roof — preventing snow from draining from the roof when it melts. Wind-driven rain is rain that blows horizontally, which can find its way in-between shingles. As you might imagine, it’s best to avoid both of these issues, and this is where leak barriers come into play. WHERE SHOULD LEAK BARRIERS BE INSTALLED? Here is a list of the most at-risk points of a roof that can benefit from leak barriers: Rakes Eaves Around the chimney Valleys, which are the places where two angles of a roofline meet Anywhere fasteners are implemented The perimeter edges of roofing Any low slopes on the roof, because run-off can be more slow in these areas In some cases, it might be good to consider placing leak barriers on your entire roof — depending on things like climate and overall roof slope; since