There are three reasons why the basement is damp:
1 rainy season from June to August, wet air cannot be discharged quickly after entering, and cold air condenses on the cold wall to form dew. Solution: Strengthen ventilation, install dehumidifier, and cooperate with air conditioner for constant temperature.
2. Rainwater enters the soil in rainy season, and the waterproof of the external wall of the building is damaged, and the waterproof layer can't block water and guide water. There are mildew spots or wall skin on the first floor or basement interior wall. Solution: At this time, if the external wall is waterproof again, the project is relatively large. It is suggested that the wall and floor of indoor shady water should be treated with moisture in a small range to keep the water out of the wall. Especially in the case that the rainy season in the north is short and the amount of water infiltrating into the soil is not large, it is a good auxiliary remedial measure.
3. There are abundant groundwater resources or buildings near rivers and lakes. There is a large area of concealed water on the basement outer wall 40-60cm away from the ground, and there are water drops or 1-5cm seepage on the ground. The reason is that the waterproof layer of the building is constructed on the water surface of the external wall of the building, and its main function is to block and guide the water with hydrostatic pressure. The basement is immersed in underground water for many years, and the underground water is under pressure, and the characteristics of water are pervasive. As long as the seams of the waterproof layer are a little leaking (improper materials and workers' sense of responsibility ...), the waterproof layer will not work. Due to the movement of the earth's crust and the settlement of the room, the "protective layer" wrapped outside the room is easy to be destroyed. There may be no problems within two years after construction, but with the accumulation of water, problems appear. Solution: Moisture-proof problems are also varied and mixed together. Find a professional moistureproof person to analyze the situation and come up with a reasonable solution that suits you.
It is best to carry out moisture-proof construction at the same time of decoration, which will have better effect and lower cost. Choosing the right products and construction methods can basically keep the basement dry permanently, and there is no need to pay extra for continuous moisture prevention.
If your room has been renovated, the construction will be more complicated and the decorative surface needs to be removed, so make a moisture-proof and waterproof plan before renovation.