Locals 21, 56 and 74. Our Union represents a wide range of trowel trades in the Chicagoland area including Bricklayer, Concrete Specialist, Foam Insulator, Marble Mason, Marble Finisher, Mosaic Worker, Plasterer, Pointer Cleaner Caulker, Precast Worker, Refractory Worker, Stone Mason, Tile Layer, Tile Finisher, Terrazzo Worker, Terrazzo Finisher and Welder.