A specialty classification that involves fabrication, assembling, erection, installation, alteration, and repair of glass, glazing and allied construction products. The scope of work includes the installation of all types of windows and glass, whether fixed or movable to existing walls, floors, or columns, and the cutting and installation of glass and mirrors. Also included is installation of prefabricated glass, metal or plastic curtain walls or panels, caulking, shower and tub enclosures, and installation or replacement of wind-borne debris protection devices incidental to such work and assembly.