What Causes Damp & How to Spot It Early in Your Property

Damp is a common and costly issue in UK homes, particularly older properties. According to the English Housing Survey, around 904,000 homes in England had damp problems in 2022. That’s a staggering 4% of properties in the county. Left untreated, damp can damage your walls, woodwork and furnishings, while also creating the ideal environment for mould growth.

Whether you’re a homeowner or a landlord, understanding what causes damp and knowing how to spot the early signs can save you time, stress and money in the long run.

In this guide, we explain how to detect damp early, what to look out for, and when to seek professional help.

What Causes Damp?

To properly tackle damp, it’s important to understand what causes it. Broadly, damp occurs when unwanted moisture enters or builds up within a property. The most common types include:

• Rising damp: Caused by moisture moving up from the ground through walls and floors, often due to a failed damp-proof course.
• Penetrating damp: Caused by water leaking through walls or roofs, usually as a result of structural issues like cracks or broken guttering.
• Condensation damp: Occurs when moist air meets a cold surface, leading to water droplets and eventually mould. This is common in poorly ventilated areas like kitchens and bathrooms.

Each type may present differently, but their symptoms often overlap; which makes accurate diagnosis essential.

Early Signs of Damp to Look Out For

Detecting damp early can help you avoid major repair work later. Here are the key indicators to look out for:

1. Musty Smells

A strong, earthy or musty odour is often the first warning sign. Even if you can’t see visible damage, damp smells are a sign that moisture is present and mould may be developing behind walls or under floors.

2. Peeling Paint or Wallpaper

When damp is present, moisture can cause wallpaper to bubble, lift or peel, especially near skirting boards or ceilings. Paint may also flake or discolour in patches.

3. Discoloured Walls or Ceilings

Look out for brown or yellow staining, particularly in corners, alcoves or behind furniture. These patches are common signs of penetrating damp or roof leaks.

4. Mould or Mildew Growth

Black mould spots, often found around window frames, ceilings or in bathroom corners, are a telltale sign of condensation damp. According to the NHS, exposure to mould can worsen respiratory conditions like asthma. It’s important to address both the mould and its cause.

5. Damp or Cold Walls

If a wall feels cold or damp to the touch, particularly during winter, it could be due to moisture absorption. This may also affect the internal temperature and increase heating costs.

6. Salt Deposits or Crumbling Plaster

With rising damp, you may see white salt deposits or bubbling plaster on lower walls. Over time, the plaster may flake off or crumble completely.

7. Condensation on Windows

Persistent condensation on the inside of windows, especially first thing in the morning, may indicate high humidity and poor ventilation – conditions that contribute to damp.

How to Detect Damp Early

Here are some simple steps homeowners and landlords can take to catch damp before it worsens:

• Inspect regularly: Walk around your property, especially after heavy rainfall, and check walls, ceilings, window frames, and loft spaces.
• Landlords: Under the Homes (Fitness for Human Habitation) Act 2018, you’re legally required to fix damp-related issues.
• Monitor humidity levels: Use a hygrometer to monitor humidity, ideally keeping it between 40% and 60%. Levels above 60% increase the risk of condensation damp.
• Ventilate properly: Keep rooms well-ventilated, especially bathrooms and kitchens. Use extractor fans or open windows regularly.
• Check exterior brickwork and gutters: Damaged pointing, overflowing gutters, or missing roof tiles can all let water in.
• Get a damp survey: If in doubt, a professional damp survey can assess the cause and extent of the issue using moisture meters and thermal imaging.

When to Call in the Experts

If you spot any of the signs above and aren’t sure of the cause, it’s best to seek professional advice. At Croft Preservation, our experienced damp specialists can carry out a thorough inspection using moisture meters or thermal imaging to pinpoint the issue, and recommend the most effective treatment. No matter whether it’s repairing a damp-proof course, improving ventilation, or treating affected walls.

Protect Your Property Before It’s Too Late

Damp can start subtly but escalate quickly. By understanding what causes damp and knowing the early signs to watch out for, you can protect your property’s structure, value and indoor air quality. Regular checks and timely intervention are key, so don’t ignore the signs.

If you think you might have a damp problem in your home, call our team on 01202 737739 or complete our online contact form to book a professional damp survey.