Rising damp: causes, signs, and solutions

If you are a homeowner or looking to buy a home in a wet climate or near wetlands, you may come across rising damp.

Luckily for us in Perth, we live in a Mediterranean climate, with hot, dry summers, however we still have cool, wet winters and a number of wetlands, so it’s important to still be aware of potential rising damp.

Damp patches on walls are definitely something that should be investigated with a structural building inspection. However, they shouldn’t scare you away from purchasing a property as they can be fixed.

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What is rising damp?

Damp is moisture-caused damage in the brickwork of a building. It can result from moisture absorbed through intrusion from outside or condensation from within the structure.

Rising damp, when left unattended overtime, can create a lot of problems including structural defects.

This article will discuss the causes, signs, and treatments of rising dampness.

Causes of rising damp

Whether the rising damp is attributed to moisture entering through the wall cavity or condensation due to lack of ventilation, dampness on interior walls can cause Perth homeowners a wide array of problems.

The main reasons rising damp occurs are:

  • A change in environmental conditions that the damp proof course cannot handle (such as a rise in ground level).
  • The damp-proof course has been damaged or has become faulty.
  • There is inadequate sub-floor ventilation, causing a humidity build-up and restricting the evaporation of damp air.
  • There is debris in the sub-floor obstructing ventilation under the structure.
  • Leaking pipes, resulting in drainage issues.

6 Common signs of a rising damp issue

1. Stained walls

The most obvious sign of rising damp is the appearance of stains on the walls and floors.

If the lower part of your wall is stained but doesn’t appear to be wet, it may be becoming temporarily wet from periods of extreme weather or the rise of moisture in the ground due to high tides.

However, the inside of the wall could contain moisture due to continuous dampness issues, but not enough moisture that the wall’s exterior feels wet.

2. Peeling wallpaper

Dried wallpaper glue becomes rehydrated and ineffective when moisture builds up in walls. This causes the wallpaper to become loose and peel off the wall.

3. Flaky or bubbling plaster

The moisture from rising damp causes plaster on walls to weaken significantly and sometimes flake off the wall. This causes obvious aesthetic damage to the plastered walls in your property and will continue spreading until the rising damp is resolved.

4. Weakened skirting boards

Skirting boards are so close to the floor that they are usually the first to fall victim to rising damp.

You can identify rising damp in skirting boards as the wood will start to decay and become mushy. This is due to excess moisture impacting the timber, causing a fungal attack.

5. Black mould

If you have black mould, you have a condensation problem. In turn, your structure is likely suffering from rising damp or another damp issue.

You can normally identify if the issue is rising damp as the black mould would be growing on the lower portion of the walls or the floors.

6. Reappearing mould

Mould is a very common symptom of any damp issue.

An early sign of mould is a musty smell that will fill a room. It can spread at an alarming rate and affect the health of those who come in contact with it. So, if you see mould appearing in your home, make sure not to delay diagnosing the issue.

4 Steps to treat rising damp

Depending on the severity, rising damp doesn’t make a home uninhabitable and shouldn’t necessarily turn off potential home buyers right away. However, once you notice it, you should take action as soon as possible to stop it quickly spreading through your home and becoming a costly repair.

Rising damp can often be mistaken with other damp issues, so diagnosing the issue is essential so that you can address it with the correct approach.

Here are four steps to fixing rising damp.

1. Use damp proofing injection cream

The first step to fix rising damp is applying a damp proofing injection cream. The cream is injected or hand-pumped into specially-positioned holes in the mortar course. Once inserted, the cream liquefies. This allows it to penetrate the bricks, making them waterproof and stopping the damp from spreading.

2. Remove wallpaper and plaster work

In the case of both external and internal walls, you need to remove any wallpaper and plaster covering the affected area. This will help you identify the issue that needs to be fixed.

3. Chemical injections

Once the issue has been identified and resolved, a chemical injection is applied to reseal the damaged damp proof course. Through the years, the formulations have improved and are now proven to provide lasting protection against damp rising.

4. Replastering after treating rising damp

After injecting the new damp proof course, you’ll need to replaster the affected area. It’s a good idea to have the plaster use a high-quality water-resistant plaster to deter any possible future issues from quickly getting out of hand.

Identifying rising damp with SURE Building Inspections

Is your Perth home or the property you wish to purchase showing signs of rising damp?

At SURE Building Inspections Perth, we are an inspection company that can correctly identify damp, and the extent of damage to the structure.

Please don’t hesitate to contact us today on 1300 787 327, or click ‘Book now‘.

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