What is rising damp?

UK Home Improvement

What is Rising Damp?

No matter what kind of property you live in, it’s essential that you can relax safe in the knowledge that your health is not at risk.

However, there are a number of issues that regularly occur in domestic properties that can put you and your loved ones at risk if not properly dealt with. One of these is rising damp. 

Rising damp is actually one of the biggest problems that UK households deal with, and if not correctly treated the consequences can be costly. 

In this article, we’ll take a look at the question of ‘what is rising damp’, outline the causes and how you can treat the problem. Read on to find out more… 

What Is Rising Damp?

Rising damp is a form of damp that impacts the walls of buildings. The condition is caused by moisture from the ground that rises up through walls via the process of capillary action – hence its name rising damp. 

Essentially, the moisture is sucked vertically through a wall, travelling through tiny tubes and gaps in the brickwork.  

Typically, walls will also contain porous materials like plaster and timber that can be found in skirting boards, floorboards and joists. It’s extremely easy for these types of materials to absorb the water causing them to rot.  

Generally, the damp will be visible on household walls and so can be easy to spot. If not properly treated, not only can it cause costly physical damage to the property, but those living within it can also suffer from various health issues. 

What Is Rising Damp Caused By?

Now we’ve outlined what rising damp actually is, let’s take a look at how it is caused. 

The most common cause is a lack of damp proofing. 

The majority of properties will have some kind of barrier installed at the bottom of the building that will prevent moisture from rising upwards. This is known as a damp proof course (DPC). 

Usually, DPC is made from non-absorbant, water resistant materials but if your property does not have any installed or yours has become damaged, it can result in the presence of rising damp. 

Older buildings in particular may be susceptible to rising damp. This is because their original barrier may be worn, damaged or simply no longer fit for purpose. Often, people might not even realise their DPC is not working until they start seeing the common symptoms of rising damp appearing in their home. 

Another common cause of rising damp is if the DPC has become bridged. This is when a construction issue causes the rising damp to bypass the house’s DPC. 

Problems that could cause DPC to bridge include:

  • Debris in or damage to the wall cavity 
  • Insufficent insulation in the wall cavity
  • Plaster overlapping the DPC
  • Solid flooring
  • Raising the external ground level above the DPC
  • And more

So, if you find yourself wondering ‘what causes rising damp?’, it’s likely to be one of the reasons above.  

Signs Of Rising Damp

As mentioned above, people often don’t realise that their property has a rising damp issue until they start to notice common signs of it. 

With this in mind, it’s important that you keep an eye out for the following common signs of rising damp:

Tide-mark Stains 

One of the most obvious signs of rising damp is a ‘tide-mark’ stain that has appeared around the bottom of an internal wall. 

Water that has risen through your walls may start to evaporate, leaving a stain that will be damp to the touch. As well as a tide-mark, a yellow/brown stain may also be left behind on the wall. 

Often, this kind of stain will be accompanied by hygroscopic salt on the wall. This leads us neatly onto… 

Visible Salt 

As refrenced above, the presence of salt in a property is often a sign that rising damp is an issue. As well as showing up inside, a bigger indication of rising damp is if you spot salt on your external walls. 

As the moisture rises, salt from the water may be left on the wall. If you see any white deposits on your bricks, it is one of the clearest signs that you have a rising damp problem. Often, this will also be accompanied by a damp smell near the wall.   

Damp and Decaying Skirting Boards 

If you’ve been dealing with a rising damp issue for a while, it’s likely that more than just your walls will be impacted. For example, skirting boards may start to rot due to the damage being caused to them by the water. 

If you notice crumbling, cracked, flaked or peeling skirting boards, it might mean that damp is causing damage.  

Wet Wallpaper 

Over time, the damage caused by rising damp can become more and more severe, causing problems with anything that has come into contact with your internal walls. If you have wallpaper on your wall, you may see it start to peel and come away from the wall. 

This will particularly be the case with wallpaper that is close to the skirting boards at the bottom of your wall. 

While it might also be a sign of condensation, you can confirm if it’s a rising damp issue by feeling the wall with your hand. If you feel the wallpaper cracking or crumbling, damp may be the culprit. 

Black Mould On Walls 

If your house is particularly humid or has been exposed to a large amount of moisture, black mould could form on the walls. This mould is also a sign of condensation, but if it has appeared along the skirting boards and nowhere else in the house then it might be rising damp.  

In addition to the causes listed above, the presence of rising damp will also often create a musty, damp odour across the property. The smell alone will not be enough to diagnose a damp issue, but if it is in conjunction with the signs we’ve outlined, it might reinforce your suspicions of rising damp. 

How To Treat Rising Damp

Undoubtedly the best way to treat rising damp is by using a damp proofing injection cream. There are a variety of options on the market but they all work in a similar way. 

The product works by injecting cream into a wall’s mortar where it will quickly absorb into the brickwork. Once completely absorbed, the cream will use its water-resistant properties to repel water from rising up the wall. You should check that the DPC has not become bridged before injecting it with the cream treatment. If it is, then the damp may return in future regardless of the cream.  

Alternatively, you can treat the issue of rising damp by installing a brand-new DPC layer. However, this is often a more costly and far more complicated process.   

While the injected cream will help prevent further damp from occurring, if you already have damage to your internal walls it’s important to address that, too. 

Usually, wherever you see rising damp on an internal wall, it must be treated. You’ll have to remove all wallpaper or plaster, stripping it all the way back to the wall’s brickwork. Then, re-wallpaper or plaster the wall.  

Once you’ve conducted your treatment, be sure to monitor the moisture levels in the affected areas. You can do this by simply checking the area for dampness with your hands or, if you want to be more precise about it, using moisture meters. 

If moisture remains high despite your best efforts, it may be best to seek professional help.

Health Issues Caused By Rising Damp

It’s important that any areas in your home that have been affected by rising damp are appropriately treated. This is because the damp, mouldy environment it can cause can lead to various health issues if left untreated. 

While it’s important to note that not everyone exposed to rising damp will develop health problems, those with certain sensitivities or pre-existing conditions might be particularly vulnerable. 

Some conditions that have been linked to living with rising damp include:

  • Respiratory problems – The most common issues caused by rising damp will affect respiratory systems. For example, mould spores can trigger asthma attacks or exacerbate existing symptoms. Likewise, allergies can be made worse by mould spores and dust mites that thrive in those conditions. Reactions could include sneezing, runny noses, itchy eyes and more severe conditions. 
  • Fungal infections – In some circumstances, exposure to mould or damp can lead to fungal infections on the skin or respiratory tract. 
  • Bronchitis – Those who are exposed to damp and mouldy conditions for long periods of time will face an increased risk of developing bronchitis – especially if they have other respiratory conditions. 
  • Immune system – Research suggests that living in damp and mouldy environments can weaken immune systems, hindering their response to infections and illnesses while also making people more susceptible to other health conditions. 
  • Negative mental health – If prolonged for long periods of time to damp or mouldy living conditions, it can take a toll on an individual’s mental health and well-being. This is because living in an uncomfortable environment can lead to fatigue and irritability which can then lead to stress and anxiety.  

If you suspect you have rising damp in your home, it’s important to address the issue as soon as possible. As well as the information in this blog, our website is full of other helpful guides on a whole host of home improvement topics, so be sure to check them out. 


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