Identifying and Treating Rising Damp
By Wirral Waterproofing
Rising damp commonly affects the interior and exterior walls of a property. It is the result of moisture from the ground being drawn up through a building’s walls by capillary action. This means that the ground water travels through the miniscule holes found in a range of porous building materials, including bricks, wood, plaster, and mortar.
Easily noticeable by the familiar ‘tide marks’ it leaves on interior walls, rising damp poses a serious risk to the structural integrity of your property, if left unattended.
Treating Rising Damp
Fortunately, rising damp is easy to treat, once you have identified it. The most cost-effective and efficient way to do so is with a damp proofing injection. Holes are drilled at key points in your wall’s mortar and a damp proofing cream injected into them. The cream reverts into a liquid state, getting absorbed into the mortar and forming a waterproof barrier.
To successfully treat rising damp, you need to strip away any affected plaster and wallpaper down to the original brickwork. This area then needs to be replastered and re-papered once the treatment is complete.
What Causes Rising Damp?
Most properties in the UK are fitted with a damp proof course (DPC). This layer of water-resistant material forms a physical barrier at the base of the wall to prevent water from being drawn up. Over time, the DPC can fail or deteriorate, leaving a route for the water to rise. In other cases, the DPC might be intact, but the water can bridge the barrier, often due to a construction fault. This includes the exterior ground level being raised above the DPC, use of certain types of insulating material in the walls, solid floors, and so on.
Identifying Rising Damp
The most common sign of rising damp is a tide mark on the wallpaper or plaster of your interior wall. This is where mineral salts have been drawn up through the wall, along with the water, and stained the plaster or wallpaper. These often reach as high as a metre from floor level, though sometimes they can extend even higher.
Other tell-tale signs include:
- dark patches on the walls that are damp to the touch
- peeling wallpaper and blistering paint
- a damp, musty smell
These are also common identifiers for other kinds of damp, such as penetrating damp. Because of their similarity, it’s important to get a full damp survey to determine the exact nature of the problem.