The main humidity problems encountered in a house: description, solutions


Humidity is a problem we encounter in many homes, including recent ones. When its presence in the ambient air is greater than the recommended limit, it presents a danger to your home, but also to your health.

If it forms brown stains on your walls and ceilings, or even mold, it is already well installed. It then threatens the quality of your home and can cause allergies and respiratory problems among its occupants. It is important to act quickly and well to treat the cause of this dampness. Here are some tips to guide you.

A damp house? What are the symptoms ?

For a home to be healthy, the ambient air must not contain more than 45 to 50% humidity for an average ambient temperature of 20 ° C. When signs of humidity appear, it means the air is loaded with more than 75% humidity, which can be hazardous to your health.

The symptoms of too high humidity are numerous: saltpetre, dry rot in the wood, dark spots or halos form on walls and ceilings; the joints fall apart; the upholstery, coverings and plasters come off; the paint swells and blisters on the surface; a musty smell, mold or mist on the windows (outside your shower outlet) appear.

When you see these symptoms, it is imperative to act quickly. Otherwise, your home will continue to deteriorate slowly and will be affected in its structural parts. It may also become a danger to your health. A damp house has consequences for its inhabitants and the bacteria and mold that develop there can cause allergies, respiratory and joint problems, etc. Do not wait to act, your health depends on it!

Where does the humidity come from?

The presence of humidity in a home can have several origins, which can sometimes even be cumulative.

Hair lifts

If you notice moisture stains on the floor, it may be capillary rise. Water naturally present in the soil is absorbed by poorly built foundations and rises in the walls, causing significant damage, but fortunately reversible.

Water infiltration

Water infiltration is seen by the appearance of damp spots on interior and exterior walls. This problem is mainly visible in old constructions whose coating has become porous and / or is poorly insulated, but they are also possible on more recent constructions that are poorly designed and have microcracks around the windows, doors, joints and the wall. roofing.

Condensation and ventilation failure

This type of phenomenon usually occurs when ventilation is defective or when the home is not properly ventilated. If you see moisture stains and traces of mold in bedrooms, kitchens and bathrooms, it may be condensation. This is formed by the sudden presence of a large amount of water vapor (when cooking or taking your shower or bath) that cannot be evacuated properly. As a result, this water vapor settles on the walls and forms stains.

Most older homes suffer from poor insulation. On the other hand, if new constructions are well insulated, they require good ventilation to allow air to circulate and renew itself and moisture to escape naturally.

Leaking pipes and flow lines

Unfortunately, this phenomenon usually does not appear until several months after its onset, or even several years. When moisture stains form, it means your wall is already waterlogged.

A poor workmanship during construction

When a house is built, it goes through several stages, from digging the foundation and laying the screed to the final finishing touches. Most of these steps require a certain amount of water, therefore a long drying time. If these deadlines have not been properly respected, the humidity is stored and ends up coming out little by little.

What are the possible solutions against humidity?

To avoid embarking on expensive work for nothing, it is advisable to call a professional to perform a diagnosis and identify the real cause. Either way, don’t just cover up traces of moisture with paint, paneling, upholstery or various plasters. You would only push the problem away and soon you would see those misery caches getting smudged again. Hiding the moisture does not cure it and will cause you to spend money unnecessarily on beautification work. The other mistake not to make is to coat the walls with insulation or anti-humidity product. It just keeps the water inside the walls. Result, it extends until it finds another exit door. Finally, don’t equip yourself with living room dehumidifiers thinking they’ll solve the problem; yes, they collect excess moisture, but this is only a dressing, not a treatment!

The professional will be able to identify the causes of humidity and establish the right action plan, intended to definitively overcome it. To do this, several solutions can be proposed to you:

  • Completely rethink ventilation and clean up the current system. If necessary, it should be increased and sized better for your home. The installation of a CMV (Controlled Mechanical Ventilation) also allows humid air to be evacuated from the various rooms.
  • Install a waterproof membrane on floors and walls in contact with the earth to better insulate them from water.
  • Dry the walls using suitable treatments and devices.
  • Set up a water drainage device all around your home.

By calling a professional quickly, you will avoid wasting time and money and making the wrong diagnosis. Make several quotes from different providers and choose the one that suits you, able to do serious work.

For information, ventilation is compulsory for all housing built since 1982. It can take the form of a CMV called single flow (controlled mechanics), called double flow (to heat the fresh air), known as VMR (distributed mechanics) or VMI (mechanical by insufflation).

Small daily anti-humidity tips

There are little rules and tips to prevent moisture build-up:

  • Ventilate your home and ventilate it properly: that’s the basics! Air your home for between 5 and 10 minutes every day. The air is renewed and excess moisture is naturally evacuated. Complete these simple actions with an adapted and functional ventilation.
  • Do not dry your laundry anywhere: if you cannot leave it outside, prefer a well ventilated room to prevent the moisture from the laundry evaporating and settling on the walls.
  • Never block the air vents: they are sometimes – especially in modern ultra-insulated homes – the only way to let air through.
  • Keep the ventilation system on, even at night. The evacuation will be done automatically and regularly, leaving no time for humidity to settle.
  • Watch for cracks around windows and doors. But don’t just plug them in just any way, otherwise you risk moving the problem around without solving it.