Rising damp happens when groundwater travels upward through the walls or floors of your home — the same way a sponge soaks up water. This moisture carries salts and minerals with it, which then damage paint, plaster, timber, and masonry over time.
The Main Cause: A Failed or Missing Damp-Proof Course (DPC)
Most Australian homes are built with a damp-proof course, a barrier designed to stop moisture rising. Rising damp occurs when this barrier has failed, has been bridged by soil or paving, or is missing altogether, which is common in older or heritage homes. When the damp-proof course is no longer functioning, groundwater can move freely up through bricks, mortar and concrete.
Other Contributing Factors
While the root cause is always moisture rising from the ground, certain conditions can make the problem worse. Poor drainage around the property, high groundwater levels, older construction methods, porous building materials and salts in the soil can all contribute to more severe rising damp. These issues don’t cause rising damp on their own, but they can intensify it once the damp-proof course (DPC) has failed.
Why It Matters
Rising damp doesn’t go away on its own, and it typically becomes more severe over time. Identifying the cause early ensures the right treatment is used and prevents long-term damage to your home.
