If allowed to fester, humidity becomes an increasingly serious problem. Damp areas, mold, and crumbling walls can all harm you and your home.

Here are the warning signs to look for so you can spot any problems as early as possible and then begin to address them with humidity reduction methods.

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Immediate signs of moisture

The sooner you can identify and eliminate moisture, the less likely it is to cause structural or health problems.

Watch out for these five key signs of damp:

1. Smudged or dark, discolored spots on ceilings, walls or floors. They might be wet or smell musty.
2. Growth of mold and mildew. This can be green, black or white and can cause or worsen health problems, particularly those related to respiratory problems.
3. Damp or musty odors, often in poorly ventilated areas.
4. Peeling wallpaper, crumbling plaster, or peeling paint, which can be caused by moisture trapped behind the material.
5. Structural damage. This could be rotten wood or weakened walls, floors or foundations. For example, floorboards may be soft or spongy.

Different types of moisture will require different solutions depending on their root cause. Reducing humidity in your home is a good place to start – learn more about reducing humidity below.

Visit our guides to identify what type of humidity affects your home and discover how to get rid of moisture.

Do you want to immediately combat humidity? Visit our guide to best dehumidifiers

How to Spot and Test for Moisture Problems

Sources of moisture may be hidden throughout your home, but there are ways to see if water is seeping into or throughout your property.

A leaking gutter or drain pipe can spill water onto a wall and cause damp problems. People often don’t realize they have a gutter problem because we generally don’t spend a lot of time outside when it’s raining.

If you suspect a problem, wait until a day of heavy rain, then stay outside and monitor your gutters, downspouts and drains for leaks.

If you need to repair your gutters or drains, use our Which? Trusted traders service to find a merchant you can count on.

If you have unexplained moisture spots on your kitchen or bathroom walls or floors, check for leaks in any light fixtures or appliances, such as showers or dishwashers.

Moisture meters, or moisture detectors, can be used to measure the amount of water present in a material. It can then tell you if there is excess that is causing damage.

They can be used on paper, wood, drywall or concrete.

Although it can’t tell you if mold is present, a moisture meter can be used to generally identify areas where mold and moisture are more likely, due to excess water. You may then need to take additional steps to remove the moisture or call in a specialist.

Discover how much does it cost to repair damp in our complete guide. Prices are provided by the Royal Institute of Chartered Surveyors (RICS), using its Building Cost Information Service (BCIS) database.

Reduce moisture problems

There are a number of different causes and types of damp. The type you have will determine the severity of the problem and how to fix it.

Visit our guide to different types of humidity to identify what you are dealing with.

If you notice early signs of damp, take action immediately to prevent the problem from getting worse.

These three tips are a good way to start reducing buildup, spread and damage, and are smart preventative measures everyone can take in their home.

1. Reduce Moisture Buildup

Try to avoid releasing excess moisture into the air in your home without proper ventilation in place. Drying clothes indoors, showering, and cooking release moisture into the air, which can create excess humidity and humidity. Although these are unavoidable, you can reduce their effect by:

• Dry clothes outside when possible
• Wipe excess water off the walls after showering
• Use extractor hoods in the bathroom and kitchen: if you don’t have one, always open a window when bathing, showering or cooking something that releases steam.

2. Buy a dehumidifier

Many homes can benefit from a dehumidifier to extract excess moisture, especially in winter. They are especially useful if you often dry clothes indoors.

Dehumidifiers are available in a range of capacities, from seven liters to 40 liters. The model you’ll need depends on the size of your space, how many people live in your home (because more people usually means more showers and more laundry), and the severity of your humidity problem.

Read our guide to best dehumidifiers to choose the right model for your home.

3. Improve window ventilation

Even in winter, make sure to open your windows regularly, especially when cooking, washing dishes or taking a shower.

Keep windows free of condensation to prevent damage or mold growth. If yours are often damp, wipe them with a towel or squeegee.

You can also try a window vacuum. Find out about the best window vacuums in our dedicated guide.

If humidity is a persistent problem, you may need to improve your ventilation overall. Adding air vents to the top of window frames can be a great solution.

While these three tips will be very helpful for you to avoid dampness due to daily moisture buildup, if you have a serious problem, you will need to identify the root cause, which could be a structural problem. – and you may need help to fix it.

For more details on dealing with serious damp issues, such as damp proofing treatments, read our guide on how to get rid of moisture.