Understanding Rising Damp: Misdiagnoses, signs, and next steps

Rising damp is a rare type of damp, frequently misidentified and over-diagnosed. In many cases, damp issues identified as rising damp are a different type of damp that has been mislabelled. This misidentification can lead to incorrect treatment by property owners and organisations and an unsafe living environment for tenants. This blog will help you understand why rising damp is often misdiagnosed and what steps to take to ensure you understand how to identify and manage any type of damp in your buildings.

Damp occurs in different forms, with the most common types being rising damp (most common in older buildings but most rare in buildings built this century), penetrating damp, and condensation, as well as damp caused by disrepair. All forms of damp result from excessive moisture or water, which can lead to mould growth. Correctly identifying the type of damp is key to determining the most effective remedial action, but this can be challenging due to their often similar appearances and symptoms. To safeguard your property and tenants from mould, it’s essential to eradicate the damp regardless of its type.

To discover more about damp and mould, including your responsibilities as a landlord, download our FREE Landlord’s Guide to Damp, Mould and Condensation.

What is rising damp?

Rising damp occurs when moisture from the ground is drawn upward through tiny channels in the walls of a building via capillary action. The moisture can only rise to a maximum of 1.5 metres; after that, the effects of gravity prevent it from rising further. This water contains salts that also travel upwards, often leaving salt residue on the walls in addition to damp patches. These are hygroscopic salts that are left behind on the wall and attract moisture from the air, meaning they can cause further damp issues compounding on top of each other. Due to the nature of rising damp, this hazard can only occur in a ground level room, meaning that if you notice damp upstairs, it is likely a different type of damp.

Signs of rising damp

Rising damp is often first noticed by the damage it causes to the walls of a building. Some common signs you have rising damp are listed below:

• Tidemarks and damp patches on the wall (the most common sign)
• White salt deposits on the wall
• Peeling wallpaper and crumbling plaster
• Damaged or decaying skirting boards
• Musty or damp smell

Unsure what type of damp you’re dealing with? Get in touch with an expert to arrange a Damp and Mould Survey for an accurate diagnosis. 

Causes of rising damp

Rising damp is usually caused by a failure in the building’s Damp Proof Course (DPC), allowing ground moisture to rise through the walls. However, even with a functional DPC, certain construction defeats can lead to rising damp. Common causes of this include:

• Debris in wall cavities or subfloor voids
• Plaster or render overlapping the DPC
• External ground level being higher than the DPC
• Inappropriate insulation material in the cavity
• Solid floors
• Intersecting masonry structures or garden walls 

The misdiagnosis of rising damp

Rising damp is a complex hazard to identify and is often confused with other forms of damp, particularly condensation. Accurate identification requires thorough testing, such as gravimetric testing, moisture testing (with a protimeter), and salt testing. These tests can be time-consuming and costly, leading to frequent misdiagnoses. It's easy to mistake other damp issues, especially penetrating damp, for rising damp without thorough investigation.

To avoid misdiagnosis, it’s best to consult experienced damp and mould surveyors who can perform the necessary tests and provide an accurate diagnosis. This ensures the appropriate remedial treatment is implemented for the correct type of damp.

Your next steps to address damp and mould

Unsure whether you’re dealing with rising damp? Get in touch with one of our expert damp and mould surveyors to find out if you have had a misdiagnosis, what type of damp you actually have, and the correct recommended remedial actions. Every building is unique, and your Damp and Mould Survey should be tailored to address your specific damp and mould challenges.

At Pennington Choices, we offer bespoke Damp and Mould Surveys that cater to your individual needs. We use a tiered approach, ensuring our assessments are thorough, bespoke, and actionable. Get in touch to have a chat with one of our damp and mould surveyors and arrange a survey to get to the bottom of your damp hazards.

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