A gap filler member apparatus for blocking air flow through a gap existing between an edge of a first electronics board and a surface of a second electronics board that is disposed generally perpendicular to the first electronics board, where the first and second electronics boards are coupled by at least one pair of connectors and disposed within an electronics equipment enclosure, to block air flow through the gap. The apparatus has at least one rib extending therefrom, with the base portion being secureable to the surface of the second electronics board. A rib extends away from the base portion and has a height approximately equal to a height of the gap, and a length at least as long as a length of the gap so that the rib at least substantially blocks air flow through the gap.