A mounting assembly for fixing a wall covering comprised of a plurality of panels on a wall comprises a support member which is fastened to the wall and a panel bearing element secured to each panel and an improved profiled structural element including a main web, a first groove disposed on one side of the main web for receiving the support member and a pair of second grooves disposed on the opposite side of the main web, each second groove receiving one panel bearing member. The upper of the second grooves may support the lower part of an upper panel and the lower of the second grooves the upper part of a lower panel. The upper of the second grooves may alternatively support a special panel bearing element for a panel angled with respect to panels generally parallel to the wall.