Dampness problems in your home: solutions

Damp walls, seepage, mould... In Luxembourg, more than one home in five is affected by damp problems. Fortunately, there are solutions. Here's what to do if you're faced with this type of problem.

Signs that you have a damp problem

Before you can deal with this type of problem effectively, you need to know how to recognise it. Here are the most common indicators that should alert you:

Signs you can see:

You have a damp problem if you notice :

• Moisture stains on walls or ceilings (this means that there has been seepage or water damage)
• Green or black mould in corners and behind furniture or in damp rooms such as bathrooms
• Persistent condensation on windows (particularly when there are temperature variations during the day or evening)
• Peeling wallpaper or paintwork
• Skirting boards that warp or wooden joinery that swells
• From saltpetre (a whitish powder) that develops on walls. This is particularly common in old Luxembourg buildings with stone walls.

Signs you can smell:

• Persistent musty smells in certain rooms
• An abnormal sensation of coldbecause humidity reinforces the perception of cold
• Respiratory problems (allergies, asthma or chronic coughs)
• Clothes that remain damp, even after a long drying period

To accurately measure the humidity level in your home, ideally use a hygrometer (a device that costs between €20 and €40 and allows you to measure the concentration of water in the air). If this level exceeds 60%, there's a problem.

The main causes of damp in Luxembourg homes

It can be normal to have a certain level of humidity in Luxembourg, particularly :

• If you live near a watercourse (Alzette, Sûre, Moselle...)
• If you live near a forest or large wooded area
• If it rains a lot this year or this season (humidity levels can exceed 80% in autumn or winter)

On the other hand, humidity becomes abnormal in the following cases:

• When there is an infiltration problem (roof, terrace, facade) or water damage to the structure of your flat or house
• When ventilation is inadequate in your home (if you have neither mechanical ventilation nor Double flow CMV)
• When you notice capillary rise (rising water along the walls, due to old foundations that did not insulate properly from the earth).

Immediate solutions to adopt

To combat damp effectively on a day-to-day basis, here are some simple, affordable solutions to start with:

• Air your home every day for at least 10 minutes, morning and evening, even in winter (ideally create draughts by opening opposite windows)
• Ventilate especially after showering, cooking or drying clothes
• Clear the air vents in your home and maintain them regularly
• Install air vents in rooms that don't have any

In addition, you can use devices to absorb moisture naturallysuch as minerals (coarse salt, bicarbonate of soda, charcoal) or special houseplants (Boston fernSpathiphyllum, Chlorophytum ...)

Solutions to eliminate damp for good

If, despite your best efforts, the problem persists, you'll need to renovate your home to eliminate it permanently. Here's how:

1. Call in professionals to deal with structural problems in your home. They will be able to offer you a capillary rise treatment (by injecting waterproof resins), a peripheral drainage (important for houses on slopes) and waterproofing of critical areas of your home (roof, terraces, façades).
2. Install an efficient ventilation system: Opt for a single or double flow CMV to continuously evacuate stale air and bring healthy air into your home.
3. Improve the thermal insulation of your home: the heat dries out your indoor air, and so combats excess humidity. To keep your home healthy over the long term, make sure you have a good thermal insulation. As a result, your home will retain heat better and your interior will be less damp for longer.

In addition, and temporarily, you can use electric dehumidifiers or air extractors to significantly reduce the level of damp in your home. However, these techniques will require a significant amount of electricity to operate effectively.

Ideally, if you are in a situation where the level of humidity is too high and linked to structural problems, you will need to carry out a major renovation (insulation, heating, ventilation). Fortunately, this type of renovation is heavily subsidised in Luxembourg.