Abstract: A strainer assembly for use with an indirect waste receptor comprising an internally threaded, expandable gasket member sized to be insertable into the indirect waste receptor discharge tube operatively connected to a building drain system drain pipe; a rigid support structure forming an externally threaded wall to operatively mate with the gasket member in a manner to expand the gasket member body into sealing contact with the discharge tube or drain pipe and having a spoke member extending across a rigid support structure passageway with a vertical opening in its center section; a strainer having a screw opening alignable with the spoke member center section opening; and a screw seatable in the screw opening and having a length to operative attach to the center section opening for affixing the strainer to the rigid support structure.