A damp-proof course (DPC) must be installed in walls above ground level to prevent water from rotting the timbers and keep it out of the living area.
Note: Black speckled mould growth from floor level is not rising damp; it’s just the natural growth of the fungi.
Rising damp is groundwater moving up the capillaries in a wall’s masonry and occurs in buildings that lack a barrier, known as a damp-proof course, which prevents moisture from creeping upward and slowly breaking down the masonry and abutting timber. As the water rises, it carries salts that increase dampness and damage masonry.
Its rise on a wall is controlled by:
Wall thickness.
Masonry pours size.
The amount of water at the wall base.
Rate of surface evaporation.
Rising damp issue:
Arrange for an inspection by a qualified person.
Is there a cure
- Install a chemical DPC course to control groundwater by injecting a water-repellent fluid under pressure or by a cream into the mortar joints. This course is not a barrier to water vapour.
- Install an electro-osmotic system to control rising damp by reversing its flow using an electromagnetic field that repels water and salts.
- Drain the ground around the property. This may not be practical.
- Cut into the wall and install a physical DPC. This could affect the wall structure.