After beginning of spring every year, indoor moisture regain will occur in some areas, which makes clothes and furniture damp and moldy, which is often called "southerly day".
The high indoor moisture regain in spring is because the temperature of indoor walls and floors drops day by day after winter. After spring, the indoor heating rate is slower than that outside. When the outdoor air suddenly rises sharply and is very humid, it will condense into small water droplets on the cold ground and walls, and even form a flowing water layer. If it is cloudy in the morning, the weather is too warm and there is a strong south wind, there will be a resurgence that day.
Design principles of moisture regain treatment:
First, minimize the appearance of construction joints during moistureproof construction. Since the construction of the moistureproof layer is carried out after the completion of the civil foundation project, and it is a concealed project, the subsequent construction of the moistureproof layer should be considered during the construction to reduce the occurrence of unfavorable construction conditions for the moistureproof layer construction in advance.
Secondly, the time of moistureproof construction should be after the foundation room is backfilled to avoid the damage of backfill to the moistureproof layer. Clay or loess shall be used as the filling material for moistureproof ground, and 2: 8 or 3: 7 lime soil shall be used when conditions permit, and compacted by layers, with each layer being 20cm.
Third, deal with some details. Remove sundries, mortar, etc. On the base surface, water the brick before the construction of the moistureproof layer, and keep it fully moist. When the surface of the brick is slightly air-dried, the construction of moisture-proof layer should be started in time. These details seem small and unimportant, but they will greatly affect the failure of the moisture barrier. So please pay attention.