What is the Difference Between Rising Damp and Penetrating Damp?

damp wallpaper

Dampness is one of the most common issues that property owners face, particularly in older properties. The problem is that dampness can arise from a variety of different sources, which can cause issues when trying to put an end to it. Often, people end up (temporarily) treating the symptoms of the dampness, as opposed to getting to the root cause of it and finding an appropriate solution. This is largely down to home owners being unaware of the differences between rising damp and penetrating damp; both of which are not to be underestimated.

Excessive moisture in buildings can lead to a whole host of issues such as the deterioration of the structural integrity of your home, decorative spoiling, plaster staining and mould – the latter of which can cause some serious health problems if left unchecked.

Let’s explore the differences between rising damp and penetrating damp:

Rising Damp

Rising damp is caused by water from the ground, ascending through the walls and floor, which is not being stopped by any damp proof course. This is typically found in older buildings without a damp proof course, or where it has been bridged over time.

Rising Damp has damp stains rising to about 1m to 1.5m high and at the top is usually a layer of nitrate salts on the surface.

How to spot rising damp:

  • Peeling wallpaper or paint
  • Wet patches on the wall
  • Rotting plaster or skirting boards
  • Yellow / brown staining on the lower wall areas
  • Long term damp can result in a white powdery substance caused by crystallised nitrate salts (usually spotted at a height of approx 1m)

Penetrating Damp

Penetrating damp enters the wall above the damp proof course. This is typically broken down into two different categories: Vertical Penetration and Lateral Penetration.

Lateral Penetration – A good example of lateral penetration dampness is on the walls in a basement. This is due to the fact that the walls are built against the subterranean ground outside, allowing dampness within the soil to penetrate them.

Vertical Penetration – Ultimately, most cases of vertical penetration dampness is due to poor building maintenance or defects in the structural integrity of the building. So, things like blocked or defective water draining pipes or cracks that have formed in the walls over time can lead to higher levels of concentrated water seeping inside.

How to spot penetrating damp:

  • Dripping and puddles
  • Wet and crumbling plaster
  • Blotching in paint and wallpaper
  • Damp circles on walls and ceilings which will typically darken during periods of rainfall

Worried About Damp in Your Home?

If you’re concerned about damp in your home and would like to resolve the issue before it gets any worse, then you should get in contact with Damp Detectives today! Using an effective combination of specialist training and the latest damp surveying equipment, we will be able to find the root cause of any damp problem and offer you the most appropriate solution.