Signs of penetrating damp

How to Identify Penetrating damp?

Do you think you may be suffering from penetrating damp in your property? If so, this article will explain the tell-tale signs to look out for penetrating damp.

Before we delve into looking at how to identify penetrating damp, we always recommend that you should contact a specialist damp proofing company to confirm the diagnosis of the problem. A common issue that we come across is that penetrating damp can often get misdiagnosed with rising damp. This in turn can lead to damp treatments that will not necessarily solve the problem.

Accredited to

Nic Glover

Branch Manager and Waterproofing Design Specialist CSRT CSSW
North East

There are some checks that can be made by yourself to spot signs of penetrating damp. Properties that have external defects will allow rainwater to gain entry into the inner walls of the property. This can visually impact the look and feel of the house.

Having visible damp patches and a damp musty smell is not nice for any homeowner so it is something that needs to be rectified as soon as possible. The visible signs and musty smells are not the only issues associated with penetrating damp. Dry rot can also occur if the damp problem is not sorted in a sufficient amount of time.

How to identify Penetrating Damp? What Signs To Look Out For?

Any watermarks that appear on walls, windows and ceilings will indicate that there is a penetrating damp problem. When the surveyor checks these areas of the building these will invariably show high moisture readings.

Damp patches will occur on the inner walls of your property if water is allowed to gain entry as a result of prolonged periods of rainfall. This may result in condensation developing in areas of the property where there are damp cold areas. Water droplets may also be visible if the damp problem has become a serious issue. Compared to rising damp, there will be no salts rising from the ground.

The penetrating damp symptoms that you need to look for are as follows:

  • Damaged Plaster: Plaster will show signs of wear and tear when affected by penetrating damp. The reason for this occurring is that the moisture damages the quality of the plaster.
  • Localised Dampness: Penetrating damp will cause patches of localised damp and will occur at different areas of the property. These damp patches will not dry no matter which damp proofing method is used.
  • Mould Growth on walls: Having mould occurring at the property is often a sign of condensation but it is also a symptom of penetrating damp. Therefore, we would recommend a damp specialist to diagnose the damp problem correctly.
  • Wet rot affecting Timber: Timber floors and walls that are affected by penetrating damp can lead to signs of wood rotting issues which can cause serious damage to the building’s infrastructure.
  • Damaged to the internal décor of the property: if the inner walls of the property and the decorations that are associated have become discoloured or damp, then it is more than likely that your property is suffering from penetrating damp.

surveyor identifying penetrating damp at property

Signs of Penetrating Damp Affecting External Areas of the Building

Property owners need to be aware that penetrating damp can affect both the internal and external areas of the property.

The symptoms of external penetrating damp are as follows:

  • Moss growth on the outer walls of the building: Moss and algae start to grow on walls when there are high levels of moisture. These organisms are drawn to damp areas and can spread quickly if treatment is not carried out quickly. This will cause the brickwork to deteriorate over a long period of time and is not aesthetically pleasing for any homeowner.
  • Damaged Brickwork: The most common sign of penetrating damp is having damaged brickwork on the external walls of the property. This is usually caused by frost damage. During frosty conditions, the moisture freezes and then expands. If the moisture has penetrated its way through into the brickwork then the water will expand which will then cause issues of cracks and spalling within the walls.

What Areas Are Most Affected by Penetrating damp?

Properties that have been built with solid walls are the most likely to suffer from damp from penetrating damp compared to those that have cavity walls.

Having cavity wall construction provides protection against moisture penetration. This is due to cavity walls providing an air gap between the internal and external walls meaning that there is no moisture can easily gain access to the inner walls of the building.

Property owners should be aware that this does not mean that having cavity walls makes you exempt from penetrating damp issues. There can be problems from cavities within walls where they can become blocked which then allows water access to the inner wall even though there is air gap that usually prevents this from occurring.

If there is an issue with the outer wall of the cavity then this will allow moisture to pass through to the inner wall. This could then cause damage to the insulation of the cavity. Having damp insulation transfers moisture to the inner walls of the building.

Need a Specialist to Identify Penetrating damp?

We hope this guide has provided you with a better insight into how to spot signs of penetrating damp. If there are symptoms of moisture penetration, then it is always best to have a damp specialist conduct a survey at your property, to make sure the damp problem is diagnosed correctly.

By having a survey conducted with one of our team will you have a full inspection on all areas of the property for signs of damp and potential timber-related problems as well. Once the survey has been completed then a detailed report will be sent out to you.

This will explain what was found during the inspection of the property e.g. the source of the problem. It will also detail what steps need to be carried out to make sure the penetrating damp issue doesn’t reoccur in the future. To book a survey you can contact our team online or by calling 0800 288 8660.

Related Pages