For both floors and walls, the joints between tiles are usually grouted with cementitious grout. The failed sections were repaired with grouted riprap. The drop required quick reinforcement with grouted riprap. Tiles are installed and set on mortar and grouted along the edges. With the excavation completed, the tunnel was then grouted with concrete. For partitions metal laths are grouted in with semi-fluid plaster. To ensure water-tightness, all construction joints are grouted. Foundation bolts are grouted in foundation after installation of the heater. These are then cemented together ("grouted") to form the drop structure. Using either method the annular space between the two pipes must be grouted. It was repaired in 1925 when the tower and west end were grouted and pointed. A grouted sloping boulder drop structure is the most versatile of drop structures. The pipeline was then laid through the tunnel and grouted in. The connection to the pile is usually achieved using a grouted connection. All diagonal and vertical systems must be grouted from the bottom up to the top.