Abstract: Tiles are installed on a vertical wall by employing an elongate, straight device that includes a spirit level. The device is positioned in overlying relation to the wall and rotated until it is horizontal as indicated by the spirit level. A plurality of longitudinally spaced and vertically staggered slots is formed in the device. Each slot receives a fastener so that the device can be secured to studs behind the wall. A row of tile supported by the device is then installed on the wall. The fasteners are removed after the tile installation is complete so that the device can be moved and re-used. Opposite ends of the device are configured to releasably engage a device of the same structure so that multiple devices can be linked together. An alternative embodiment is notched along its extent to provide utility in the context of convex and concave walls.