Rising damp on a wall inside house

What is The Difference Between Rising Damp and Penetrating Damp?

Damp is a common problem that can affect buildings and cause various issues if left untreated. However, if you're dealing with this problem, it's vital to distinguish between rising and penetrating dampness. Understanding this difference equips you to tackle the issue effectively, safeguarding your home's structural integrity and your health.

Let's delve into the causes, symptoms, and remedies of these damp types, and turn your damp house back into a cosy, healthy home.

First of all: What is Rising Damp?

Rising damp refers to the upward movement of moisture from the ground through porous materials such as walls and floors. It is typically caused by a lack of or failure in the damp proof course, which is a barrier designed to prevent moisture from entering the building. Rising damp can affect both internal and external walls, especially those at ground level.

Causes and Symptoms of Rising Damp

Rising damp is caused by water being drawn upwards through capillary action. This can occur when the ground level is higher than the damp proof course, or when the damp-proof course is damaged or deteriorated. Common signs of rising damp include damp patches, peeling wallpaper or paint, salt stains on walls, and a musty smell in the affected areas. Discoloured plaster and decaying skirting boards may also be indications of rising damp.

Treatment and Prevention of Rising Damp

To treat rising damp, it is important to first identify the source and fix any problems with the damp proof course. This may involve installing a new damp-proof course or repairing the existing one. You will also need to address any underlying issues that may be causing the damp, such as poor drainage or blocked gutters.

Beyond that, proper ventilation and adequate heating can help prevent rising damp from occurring in the first place, so make sure you are keeping your property well-ventilated and heated in winter.

Black mould stains on an interior wall

Effects of Rising Damp on Buildings

Rising damp can have detrimental effects on buildings if left unchecked. It can lead to structural damage, including decay of timber, corrosion of metal elements, and erosion of brickwork. The presence of moisture can also create an ideal environment for the growth of mould and fungi, which can have negative health effects on occupants. Additionally, rising damp can cause dampness in ceilings, walls, and floors, affecting the overall aesthetics and functionality of the building.

The Other Side of the Coin: What is Penetrating Damp?

Unlike rising damp, which moves upwards from the ground, penetrating damp occurs when water enters the building through exterior walls, roofs, or windows. It can be caused by various factors, including leaks, faulty guttering, or cracks in the building's structure. Penetrating damp can affect any part of the building, but it is more common in areas exposed to the elements.

Causes and Symptoms of Penetrating Damp

Penetrating damp can occur when the building's protective barriers, such as the roof or external walls, are compromised. This can be due to damaged or missing roof tiles, cracked bricks or mortar, or faulty window sealing.

Signs of penetrating damp include the following:

  • Damp patches on walls or ceilings.
  • Mould growth.
  • Water stains.
  • A characteristic musty smell.
  • Tide marks or peeling paint can also be indicative of penetrating dampness.

As you can see, the effects of penetrating damp can be far-reaching if left untreated. That's why it's important to promptly identify and address any potential sources of this kind of damp in order to avoid further damage.

Peeling of cement and plaster due to dampness

Treatment and Prevention of Penetrating Damp

Effective treatment of penetrating damp involves identifying and fixing the source of water ingress. This may require repairing roof leaks, sealing cracks or gaps in the building's exterior, and ensuring proper drainage. It is also important to address any issues with gutters and downpipes to prevent water from accumulating around the building. Implementing regular maintenance checks and promptly addressing any signs of damage can help prevent the occurrence of penetrating damp.

Effects of Penetrating Damp on Buildings

If left untreated, penetrating damp can cause significant damage to the building's structure and finishes. It can lead to the decay of timber, erosion of brickwork, and weakening of the building's integrity. The presence of moisture can also create an environment conducive to mould growth, which can contribute to poor indoor air quality and health issues. Additionally, water stains and damage to walls, windows, and ceilings can impact the overall appearance and value of the property.

How Does Condensation Differ from Damp?

While often associated with dampness, condensation is a separate issue that can occur in buildings. Condensation is the result of excess moisture in the air coming into contact with a cold surface, leading to the formation of water droplets. Unlike rising damp and penetrating damp, condensation is primarily caused by lifestyle factors, such as inadequate ventilation or excessive moisture generation within the building.

Causes and Symptoms of Condensation

Condensation can occur in areas with high humidity levels, such as kitchens, bathrooms, and poorly ventilated rooms. It is often noticeable on windows or other cold surfaces as water droplets or fogging. Other signs of condensation include mould growth, particularly in corners or areas where airflow is restricted, and a damp or musty smell in affected areas.

Peeling of plaster work due to dampness

Differences Between Condensation and Damp

The main difference between condensation and damp lies in their causes and sources of moisture. Condensation is a result of excess humidity in the air, whereas dampness is caused by water infiltration from external sources. While they may share some similar symptoms, such as mould growth and musty smells, treating condensation involves improving ventilation and managing moisture generation within the building, whereas treating damp requires addressing the external sources of water ingress.

Treatment and Prevention of Condensation

To prevent condensation, it is important to ensure adequate ventilation, particularly in areas prone to high humidity, such as kitchens and bathrooms. This can be achieved through the installation and use of extractor fans, opening windows regularly, and maintaining proper airflow throughout the building. Additionally, reducing moisture generation, such as drying clothes outside or using a dehumidifier, can help alleviate condensation issues.

Other Forms of Damp

Aside from rising damp, penetrating damp, and condensation, there are several other forms of damp that can manifest in buildings. For instance, damp caused by leaks—such as plumbing leaks or roof leaks—can give rise to localised dampness and consequential damage.

Additionally, groundwater-induced dampness or flooding can pose significant moisture-related challenges to structures. Therefore, it becomes imperative to accurately identify the specific type of damp in order to effectively implement appropriate treatment and prevention measures.

Rising damp on a wall affected by moisture

How to Identify and Treat Damp Problems?

Common Signs of Damp

There are several common signs that may indicate the presence of damp in a building. These include damp patches on walls or ceilings, peeling wallpaper or paint, musty smells, mould growth, water stains, and decaying skirting boards. It is important to note that these symptoms can vary depending on the type and severity of the damp problem.

Damp Treatment Methods

The appropriate treatment method for damp depends on the specific type and extent of the problem. For rising damp, repairing or installing a damp proof course is typically necessary. Penetrating damp requires identifying and fixing the source of water ingress, such as repairing leaks or improving gutters. Condensation can be alleviated by improving ventilation and reducing moisture generation. For other types of damp, it is important to address the underlying causes, such as leaks or flooding, and implement appropriate remedial actions.

Preventive Measures for Damp

Preventing damp problems is crucial to maintaining a healthy and structurally sound building. Some preventive measures include ensuring adequate ventilation, maintaining proper drainage, regularly inspecting and maintaining the building's exterior, and promptly addressing any signs of damage or water ingress. It is also important to implement measures to manage moisture generation within the building, such as proper ventilation in high-humidity areas and reducing moisture sources.

A damp surveyor checking mould and fungus in a room

Are You Dealing With Dampness at Home? Contact Us!

At Damp Surveyors LTD, we understand that damp can be a serious problem for British homeowners. That's why we provide comprehensive surveys to identify the causes of dampness and help you come up with effective solutions.

Our team of professionals have years of experience working on homes and knows what it takes to tackle damp quickly and efficiently. With our expertise, we can help you identify the root cause of your damp issue, determine the best course of action, and provide you with a long-term strategy to combat it.

So if you’re dealing with damp problems at home, don’t hesitate to get in touch with us today!

How can I tell if I have rising damp or penetrating damp?

Rising damp is typically found on the ground floor of a building and is characterised by damp patches or staining on the lower parts of walls. Penetrating damp can occur anywhere in a building and is usually indicated by damp patches or staining on the walls or ceilings.

What are the causes of rising damp?

Rising damp is caused by groundwater being drawn up through the porous materials in a building's walls or floors. This can happen due to a lack of or damage to a damp proof course (DPC), which is a barrier designed to prevent moisture from rising.

What are the causes of penetrating dampness?

Penetrating damp is caused by water entering a building through external walls, windows, or roofs. This can happen due to gaps or cracks in the building's structure, damaged or missing roof tiles, or faulty window seals.

How can I prevent rising damp?

To prevent rising damp, it is important to ensure that your building has a functioning damp proof course (DPC) and that it is in good condition. If you suspect that your DPC is damaged or missing, it is recommended to consult a professional for repairs.

How can I prevent penetrating dampness?

To prevent penetrating dampness, it is important to regularly inspect your building's external walls, windows, and roofs for any signs of damage or deterioration. It is also advisable to fix any gaps, cracks, or leaks as soon as they are identified.

What are the effects of rising damp?

Rising damp can cause a variety of problems, including damp and musty smells, mould growth, damage to plaster and paintwork, and even structural damage if left untreated.

What are the effects of penetrating damp?

The effects of penetrating damp are similar to those of rising damp and can include dampness, mould growth, damage to internal walls and ceilings, and the deterioration of paint and plaster.

How can I treat rising damp?

Treating rising damp usually involves installing or repairing a damp proof course (DPC) to prevent water from rising up through the walls and floors. This process may require professional assistance.

How can I treat penetrating dampness?

Treating penetrating damp involves identifying and resolving the source of water ingress. This may include repairing roof leaks, fixing damaged external walls, or improving window seals. It is advisable to consult a professional for an accurate assessment and appropriate treatment.

Table of Contents

Picture of Sam Fitzgerald – CSRT Damp Surveyor

Sam Fitzgerald – CSRT Damp Surveyor

Author – CSRT Damp Surveyor
Sam is a highly qualified and seasoned damp surveyor with over ten years of specialised experience. With a strong academic foundation in building surveying and numerous professional certifications, Sam has established himself as an authority in the field of damp diagnosis and remediation.

At Damp Surveyors Ltd, Sam applies his extensive knowledge to help homeowners across the UK address and solve their damp issues effectively. His approach combines cutting-edge techniques with a commitment to honest, client-focused service, ensuring that every survey and recommendation is tailored to the specific needs of the property.

As a thought leader, Sam’s insights into damp prevention and treatment have been featured in industry publications, underscoring his role as a trusted expert dedicated to maintaining the integrity and comfort of your home.

Testing device for measuring dampness in a house


At Damp Surveyors Ltd, we stand out as your premier choice for damp survey services in the UK. Our commitment to excellence and customer satisfaction sets us apart. Here’s why you should choose us:

  • Exclusive 3 Free Quotes: We offer a one-of-a-kind optional service where you not only get our top-notch damp survey but also receive 3 free quotes from vetted local companies, giving you peace of mind by saving you thousands on getting the most competitive quotes, and also time researching and contacting other reputable companies.
  • Knowledge and Experience: We provide unmatched knowledge to every survey we conduct thanks to our team of seasoned professionals and years of industry experience. This guarantees accurate assessments and practical solutions.
  • Nationwide Coverage: Whether you’re in a bustling city or a rural area, our services extend across the UK, making us accessible wherever your property is located. Choose us for nationwide reliability and excellence.

Choose Damp Surveyors Ltd as your reliable partner for all-inclusive survey needs. Our top concerns are the health and safety of your property, and we are committed to providing outcomes you can trust.

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