The winter rains usually makes humidity to appear in different walls around the house. When we get back to our holidays house we found it covered by humidity stains, and it is also possible for damp housing conditions to appear in your regular house.
The first step is to verify if humidity appears because of a lack of ventilation in the room or a water filtration problem. Most of the time, damp housing conditions appear because there is no correct air circulation current, by correcting this, you will avoid humidity stains.
If humidty stains appear because of a lack of ventilation, what you need is an air chamber. These chambers are essential for every house, especially in the low level. They are usually built with the house, but you can also add them later. Unfortunately, it requires quite a sum of money. There is also a cellulose insulation that can prevent damp housing conditions but it is also quite expensive.
Sometimes you can correct the flow of air by opening windows and doors daily. A good ventilation is necessary to renovate the oxygen at home and to eliminate the fumes from the kitchen or the shower. If you keep the doors and windows closed every time, humidity will certainly appear.
A good tip is to open windows when you cook to avoid steam and fumes. You should also do this when you take a shower or when you hang up clothes to dry inside a room. Another option is to buy special salts that absorb humidity.
If the damp housing conditions are caused by water leaks then it is a little harder to fix.
First you need to locate the exact spot where the filtration originates. Water flows and it can move for a long distance from the starting point to where you see the humidity stains. Before start breaking your walls, it is a good idea to obtain a thermal image of the zone where the leak may be in order to spot the leaking area.