Rising damp is an issue that can sometimes affect all buildings. It is a problem more often in older houses where the original damp proof course has become damaged.
Over time, water from under the ground works its ways through the brick, stone work or through the mortar that holds the brick work together. This water often contains soluble salts which are on the surfaces of the walls as they dry out. In turn, these salts draw moisture from the outside giving a permanent wet feeling to the wall and producing one of the indicators to help identify rising damp.