SEAM PLATE FOR RETAINING ROOF DECKING MEMBRANE

A seam plate for use in connection with securing membrane sheets to underlying roof decking substructure com- prises a substantially rectangular plate having a central aperture for receiving a bolt fastener. Upstanding rib structure is provided upon the plate so as to provide dif- ferent regions thereof with different rigidity, flexibility, and bendability properties. The rib structure can have, for example, a substantially diamond-shaped configuration or an X-shaped configuration for respectively providing corner re- gions of the plate with increased or decreased flexibility. A plurality of downwardly extending projections, having sub stantially V-shaped cross-sectional configurations, are pro- vided upon the underside of the seam plate so as to engage the membrane sheets and retain the same at their desired locations upon the underlying roof deck substructure assem- bly. The projections are arranged within longitudinally and transversely separated pairs so as to be dispersed through- out the extent of the plate so as to distribute pressure loads throughout the underlying membrane and thereby pre- vent tearing and rupture of the underlying membrane.