What Is a Roofing Fillet?

A roofing fillet is something used mainly on felt and flat roofs of houses. These fillets are made of triangle shaped wood and placed near a chimney or wall. Using roofing fillets, rain water flows off the roof properly.


A roofing fillet's main purpose is to divert rain water from remaining on a roof or flowing down a wall or chimney. Roofing fillets are also used to protect joints on roofs.


Roofing fillets are triangular pieces of wood. They are made from 2-inch square pieces of wood cut into triangle shapes, typically 45 degrees. They are placed under the slates of a roof causing the roof to be angled.


When roofing fillets are used, water exits the roof without leaving water marks on the walls or getting into the walls or chimney of the house. These fillets force water to run to the gutters of the house.