A shower floor former assembly is provided which comprises a shower floor former having a non-circular waste-plate receiver and a drain waste plate which is dimensioned to be receivable in the waste-plate receiver. A centre point of the waste-plate receiver is offset from a centre point of the shower floor former, and the drain waste plate has a drainage aperture therethrough, a centre point of the drainage aperture being offset from a centre point of the drain waste plate. The drain waste plate is receivable in the waste-plate receiver in a first condition in which the centre point of the drainage aperture is offset relative to the centre point of the shower floor former. The drain waste plate is also receivable in the waste-plate receiver in a second condition in which the centre point of the drainage aperture is coincident with the centre point of the shower floor former.