What Type Of Damp is Affecting My Home?

Damp can cause serious problems for London homes. Moisture build-up leads to property damage and can even form dangerous black mould. Fortunately, experts like Damp Proof London can remedy the negative effects of damp. As damp specialists in North London, we have the knowledge to help you eliminate damp from your home. But how do you even identify a damp problem? In this guide, we’ll show you what to look out for and explain the 3 main types of damp that can affect your home.

Identifying a Damp Problem

How can you tell your home has a damp problem? There are 3 general signs to look for. The first is the most obvious and well-known, black or dark stains on the walls. These stains are a sign of mould-build up which indicates a deeper damp problem in your home.

Damp won’t always manifest as dark stains, however. You could encounter the second sign, which is a musty or damp smell. If you have this smell in your home, you likely have mould spores and mildew somewhere. At Damp Proof London, we conduct a home survey to help you locate the source of damp smells.

The final thing to look for is curling or chipping wallpaper. This usually indicates a rising damp, even if you don’t feel or smell any damp.

Now that you’ve identified a damp problem in your home, you’re wondering what to do next. The solution to your damp problem will depend on the kind of damp affecting your home. Let’s take a look at the 3 types.

Rising Damp

Rising damp is caused by groundwater moving up through your masonry underneath the plaster on your walls. Moisture is sucked in through small holes or tubes in what is called capillary action. Rising damp is most common in basements and on ground floors.

You can spot rising damp by tidemarks near the skirting boards on your walls. These yellow or brown bands are the chlorides and nitrates (salts) left behind from the groundwater. One way to prevent rising damp is through injecting a chemical, damp-proof course in your walls. This type of treatment must be regulated, so it’s best to rely on London damp proofing specialists to combat rising damp.

Penetrating Damp

Whereas rising damp moves from the ground upward, penetrating damp can spread laterally through your walls and across your ceiling. It’s caused by water leaking through your walls and is a common type of damp in London homes.

Penetrating damp is the result of a number of things. It could be due to faults in the structure, like missing roof tiles, poorly fitted windows and doors, overflowing gutters, and leaky pipes. You can spot penetrating damp as a blotchy patch on the walls or ceiling which never airs out. The spots usually get darker when it rains. Penetrating damp will also cause a damp or musty smell.

The best treatment for penetrating damp is prevention; keep your home well-maintained and check for structural issues. Damp proofing experts in London can also give you a professional survey to identify the source of the penetrating damp.


Condensation is the most common form of damp. It occurs when moist air bounces off cold surfaces, causing water droplets to form. Condensation is most prevalent in London homes with little or poor ventilation –, especially in wintertime. Bathrooms and kitchens tend to be the most affected. You’ll see condensation on or near windows, as damp patches on your walls, or even as the black mould.

Improving your home’s ventilation is the best way to treat condensation. There are specific types of vents you can install, or you can try a simple dehumidifier. Condensation might be a symptom of a larger, more dangerous damp problem, though. As always, damp specialists can help you out if you’re experiencing persistent problems with condensation.


These 3 types of damp are the most common, but damp can be linked to other causes and symptoms as well. It’s important to stay on the lookout for the warning signs of damp and call the damp proofing specialists when you need assistance.

Let’s face it – nobody wants to deal with damp. Unfortunately, it’s a common problem for London residents. With the help of the experts, you can eradicate damp and rest at ease in your home.

Contact Us:

  • damprooflondon@gmail.com