Apparatuses, such as shower door frame kits, for installing sliding shower door assemblies are provided. The apparatuses enable secure and convenient installation of the sliding shower door assemblies, while keeping water that may escape a shower area to a minimum. The apparatuses of the present disclosure also provide for efficient installation of the sliding shower door assemblies that can be completed with a single tool and/or in a single step. The apparatuses for installing sliding shower door assemblies may include one or more of a shower door header, a wall jamb, a shower header retainer, a shower door catcher, a roller assembly, a corner bracket, and a shower threshold.