Abstract: A preformed hollow partition of plastic sheet material is disclosed for attachment to horizontal and vertical studs on the floor and wall of a bathroom to associate the partition with the plumbed end of a bathtub fixture. The partition is generally rectangular and is open along the bottom edge and one side edge thereof to receive the corresponding stud to which the partition is fastened for support. The side of the partition facing the tub is cut on site to accommodate the edge flange on the end of the tub and to provide openings for faucet, water valve and shower fittings. The opposite side of the partition is provided with an access opening to facilitate plumbing work.