Definitions for "Nailing fin"
Keywords:  fin, clad, vinyl, patio, rough
A piece of vinyl or metal band can be attached to the four sides of a window. This band or fin is used to nail through when installing a window before the installation of siding.
A vinyl or aluminum extension attached to the frame of a window or door which creates a positive seal between the window and the framed wall. Acts as an additional barrier against air and water leakage. Screws or nails are fastened through the fin to hold the unit in the opening.
A leg of the extended aluminum or vinyl exterior of clad units that forms a 90 degree angle to the window and is positioned flush against the sheeting of the building. Clad windows are easily secured in the rough opening by nailing through the fin into the sheeting and jack studs of the rough opening.