A method for mounting a shower tray, comprising the steps of: arranging a plurality of shower tray supports on the floor or on the shower tray; arranging at least one temporary mounting structure on the floor at a position within and adjacent a boundary of an area at which the shower tray is to be positioned in use, wherein the height of the temporary mounting structure is less than the height of the shower tray supports; wherein the mounting structure comprises a bottom portion having a planar structure for resting on a floor, and an upper portion having a planar structure for supporting a shower tray, wherein the mounting structure further comprises means for adjusting the distance between the planar structure of the bottom portion and the planar structure of the upper portion, wherein the bottom portion and the upper portion are wedge shaped members (11a, 11b), each of the wedge shaped members (11a, 11b) being provided with a top surface (12a, 12b), the top surfaces (12a, 12b) are connectable to each other thus forming the means for adjusting the distance between the planar structure of the bottom portion and the planar structure of the upper portion, wherein each one of the upper portion and the bottom portion (11a, 11b) forms a hollow cavity configured to receive a corner of a shower tray, positioning the shower tray onto the shower tray supports and the floor, tilting the shower tray upwards such that the shower tray is standing on the at least one temporary mounting structure, adjusting the height of at least one shower tray support, and repositioning the shower tray onto the shower tray supports. arranging a plurality of shower tray supports on the floor or on the shower tray; arranging at least one temporary mounting structure on the floor at a position within and adjacent a boundary of an area at which the shower tray is to be positioned in use, wherein the height of the temporary mounting structure is less than the height of the shower tray supports; wherein the mounting structure comprises a bottom portion having a planar structure for resting on a floor, and an upper portion having a planar structure for supporting a shower tray, wherein the mounting structure further comprises means for adjusting the distance between the planar structure of the bottom portion and the planar structure of the upper portion, wherein the bottom portion and the upper portion are wedge shaped members (11a, 11b), each of the wedge shaped members (11a, 11b) being provided with a top surface (12a, 12b), the top surfaces (12a, 12b) are connectable to each other thus forming the means for adjusting the distance between the planar structure of the bottom portion and the planar structure of the upper portion, wherein each one of the upper portion and the bottom portion (11a, 11b) forms a hollow cavity configured to receive a corner of a shower tray, positioning the shower tray onto the shower tray supports and the floor, tilting the shower tray upwards such that the shower tray is standing on the at least one temporary mounting structure, adjusting the height of at least one shower tray support, and repositioning the shower tray onto the shower tray supports.