A roofing membrane retainer is provided having a cylindrical plate. The cylindrical plate has a central aperture for receiving a fastener. The plate also includes a pair of concentric inner and outer raised reinforcing ribs and a plurality of scoop-shaped projections. The scoop-shaped projections extend downwardly from the plate in concentric inner and outer cylindrical arrays. The inner cylindrical array of projections and the outer cylindrical array of projections are radially outward of the inner rib and the outer rib, respectively. The projections each comprise a scoop with a base periphery having an open mouth edge and a remaining peripheral portion contiguous with the plate. The projections in each array are spaced equidistance about the plate. The mouth edge of adjacent projections are oriented in alternating radial inward and outward directions.