A temporary shield erected between two flanged structural members of a bridge or other structure, and a method for erection of the shield. A plurality of length-adjustable beams have end portions which are rested on flanges respectively of the structural members in a manner so that they are not fixed thereto. Decking is attached to the beams. At least one elongate member is cantileverly extended from at least one of the beams to underlie a structural member flange to prevent wind lift-up of the shield. A shield is also erected by adjusting the lengths of and hanging the end portions of each of a multitude of beams from the structure with the beams lying side-by-side. Decking is attached to the beams.