A sealing gasket assembly for sealing a head-of-wall construction including a member body having a top member with first and second spaced apart side panels depending from the top member. The intersection of the first side panel and the top member defines a first inside corner and a first outside corner and the intersection of the second side panel and the top member defines a second inside corner and a second outside corner. A supplemental sealing member extends along each of the first and second outside corners. Each supplemental sealing member is manufactured from a flexible material and is configured such that a panel abutment portion thereof extends along at least a portion of an outside surface of the respective side panel and a return portion extends along at least a portion of an outside surface of the top member.