Just bought a home built in 1940. Quickly realized that, in order to use the main floor bath as a shower, will need to tile or protect the wall above the tile line (walls are tiled up to 3.5 feet in the bathroom - possibly original tile). Lathe and plaster walls seem to be in really good shape. Is there a way to tile the wall without demoing or otherwise removing the plaster from the tile up? Really want to preserve the tile work. Any advice would be greatly appreciated. Thank you!