Damp Proof Courses can break down with age, when this happens it can allow water from the ground to enter the structure by capillary action, major pathways through which the water rises in a wall are the mortar joints. In effect, the mortar joints form the only continuous pathways for water rising through the wall.
There are various signs that can indicate rising damp, such as:
- Salt stained plaster
- Peeling paint and/or wallpaper
Even though rising damp can be controlled by the insertion of a remedial damp proof course, salts that are contained in the rising ground water can also contaminate the wall plaster.
Therefore, it is important to remove and replace the contaminated wall plaster with a new sand and cement render containing a water proofer/salt inhibitor and salt resistant plaster finish, in addition to the insertion of a damp proof course.