Damp products: measure, dehumidify and know the limits
Before treating, it pays to measure. A hygrometer costs about €10 and an infrared thermometer €15–20; with both you know the relative humidity of the room and the temperature of the walls, and can estimate whether there is a condensation risk. Then come the products that act on the air or the surfaces: 10–12 L/day compressor dehumidifiers from about €90, calcium chloride absorbers, insulating window film and anti-mould paints.
These guides are for anyone who wants to spend little and wisely. They explain what each product does, when it helps and when it is just hiding the problem.
The key idea: no product fixes everything. A dehumidifier helps a lot with condensation and does almost nothing against active water ingress; anti-mould paint delays the mould coming back but does not change the wall's temperature. Start by choosing a hygrometer and use the dew point calculator to make sense of your readings. Measurement kits are in the shop.
Start here
Hygrometers: which one to buy and how to measure correctly
The €10 instrument that tells you more about your home than many technical visits — if you know where and when to measure.
Full guide →Dehumidifiers: which one to buy and how many litres you need
Compressor or desiccant, 10 or 20 litres, how much electricity it uses and when it won't help at all. A guide with no paid brands.
Full guide →
Do moisture absorbers work? Test and limits
Where they help (wardrobes, pantries) and where they're money down the drain (whole rooms). Simple maths and the precautions to take.
Full guide →All guides on this topic (5)
Anti-mould paint: when it helps and when it hides the problem
Useful once the cause is fixed. Before that, it's make-up — and on walls with salt deposits, not even that.
Full guide →Infrared thermometers: how to use one to find cold walls
A €15–20 instrument shows where your home is cold enough for condensation and mould — if you get the emissivity, the distance and the time of day right.
Full guide →Frequently asked questions
Indirectly. It does not measure water; it measures surface temperature. By comparing that temperature with the dew point of the air, you know whether the wall is cold enough for condensation: at 18 °C and 75% relative humidity, the dew point is around 13.5 °C. Parts of the wall below that value are the likely spots for mould.
A simple absorber costs about €9 and each calcium chloride refill about €1.50. In a very damp room the refills run out faster and the cost keeps adding up. They make sense in small, closed spaces such as a wardrobe or a pantry; for a whole room, an electric dehumidifier is usually more effective.
It can reduce condensation on the glass of single-glazed windows, because it creates a layer of air that keeps the inner side less cold. It costs about €6 and comes off without leaving marks, which makes it handy for rented homes. It does not fix condensation on aluminium frames without a thermal break or on walls, and it does not replace ventilation.