If you dread a rising damp issue, you aren’t alone. The combination of Australia's diverse climate and the design of our older buildings makes rising damp a surprisingly common concern.
Rising damp occurs when ground moisture travels up through walls, leading to serious structural and health problems. Damp, mildew, crumbling masonry, and even structural decay can all happen swiftly—making decisive action your best bet to prevent major maintenance issues.
If you are worried about a potential rising damp problem in your building, or just want to be prepared, don’t stress. In this blog we will discuss the causes of rising damp, how to recognise if you have a problem, and then share our top tips for what to do about rising damp in the future.
What Causes Rising Damp?
Rising damp is often due to a lack of barrier between the ground and the walls of a building (usually called a Damp Proof Course (DPC)).
This issue largely affects older buildings as many were built without a DPC at all, but modern buildings aren’t immune. Any building can be affected if the DPC becomes damaged, or wasn’t installed correctly in the first place.
Risk Factors for Rising Damp:
- Lack of Damp-Proof Course (DPC): Many older Australian buildings were constructed without a DPC, a physical barrier installed in walls to prevent moisture from rising.
- Damaged or Deteriorated DPC: Over time, the DPC in a building may become damaged due to wear and tear, poor installation, or even shifts in the building's foundation.
- High Groundwater Levels: In areas with high water tables or poor drainage, the likelihood of rising damp increases as groundwater pressure forces moisture into the building materials.
- Poor Site Drainage: Insufficient drainage around the building's perimeter can cause water to pool around the foundation, exacerbating the risk of rising damp.
The Effects of Rising Damp
Unfortunately, moisture is kryptonite to building materials. All that water moving up through a wall into porous masonry and timber can wreak havoc on a building. Rising damp not only causes façades to crumble, it can massively affect the structural integrity of a wall and, therefore, the building itself.
The consequences of dampness on the health of a building is also well understood. Anything from unsightly moisture stains on the walls, to bad smells, to serious health issues due to mould can plague the occupants of a building with a rising damp issue.
How Do I Know if I Have a Rising Damp Issue?
Signs of Rising Damp
Identifying rising damp early is key to preventing damage. Look out for the following signs:
- Tide Marks: Visible lines or stains on walls, usually up to a metre high, caused by evaporating moisture.
- Flaking Paint or Plaster: Moisture can cause paint to bubble or plaster to crack and crumble.
- Musty Odours: Persistent dampness often leads to a musty smell, particularly in basements and lower levels.
- Salts on Walls: As moisture evaporates, it leaves behind salts that can crystallise on the surface of walls, forming a powdery residue known as efflorescence.
- Mould Growth: Damp conditions are ideal for mould, which can appear as black or green patches on walls.
What to do About Rising Damp
- Install or Repair the Damp-Proof Course (DPC): If your building lacks a DPC or the existing one is compromised, installing or repairing it can be a huge undertaking, but is by far the most effective solution. This can be done using physical barriers like plastic or slate, or through chemical injection methods that create a water-repellent layer.
- Improve Drainage: Make sure the ground around the building slopes away from the foundation to prevent water from pooling. Installing proper guttering, downpipes, and drainage systems can help redirect water away from the building.
- Use of Waterproofing Products: Applying waterproofing coatings to the external walls and foundations can provide an additional layer of protection against moisture ingress.
- Ventilation: Improving ventilation in affected areas can help reduce moisture levels, preventing the conditions that allow rising damp to thrive. This can be achieved by installing vents, fans, or even mechanical ventilation systems.
- Regular Maintenance: Regularly inspect your building for signs of rising damp and address any issues promptly. This includes checking for leaks, ensuring proper drainage, and maintaining the integrity of the DPC. If you’re looking for tips on how to establish a plan for regular maintenance, check out our quick guide for school maintenance plans.
Professional Help
While some measures can be taken in-house, rising damp is a serious issue often best managed by professionals. Specialists can accurately diagnose the extent of the problem and recommend the most effective solutions, ensuring that the issue is fixed for good.
At First Maintenance, we are experienced in managing and resolving rising damp issues. If you would like to discuss your concerns around rising damp, do get in touch for more information on how we can help. If you are looking for a quote for a school maintenance work, including rising damp management you can request one here.
Rising damp is a serious issue that can compromise the structural integrity of a building and pose health risks to occupants. In Australia, where our older buildings aren’t built for damper climates, it pays to take proactive steps. By recognising the signs and taking quick action, you can protect your building in the long term.