House wrap enclosure system
Practice has proved that no matter what type of laying is used, it is difficult to ensure the enclosure of the enclosure system. The cracking of fine aggregate concrete is difficult to avoid, and the lap joint of profiled steel sheet and tile is difficult to maintain. Through these non-sealed pores, air and water vapor can invade the envelope system, which has a serious impact on the energy-saving, durability and comfort of the building, and the house wrap envelope system can avoid this serious impact. The following are the house wrap air tightness, water tightness and steam permeability and building energy-saving, durability, comfort is closely related to several points.
1. Energy efficiency of buildings
Rainwater and water vapor intrusion into the building envelope system will reduce the effective thermal resistance of the insulation layer air flow intrusion into the building envelope system to form a convective cycle, will also reduce the performance of the insulation layer to increase heating equipment to ensure appropriate indoor temperature, thereby increasing building energy consumption.
2. Durability of buildings
Rainwater and water vapor invade the building envelope system, erode building materials, accelerate the aging of building materials, and then affect the durability of the building.
3, building comfort
The invasion of airflow has adverse effects on the thermal comfort of the room. Pollutants and radiation enter the room through airflow, thus affecting indoor air quality. Water vapor entering the building envelope is sealed in the structure for a long time, resulting in moisture generation and mold formation, thereby reducing the comfort of living.
4. condensation phenomenon
The higher the air temperature, the more water vapor can be contained, that is, the higher the saturation temperature; otherwise, the lower the air temperature, the lower the saturation temperature. When the temperature drops and falls below the saturation temperature, the water vapor will condense and separate from the air, which occurs condensation phenomenon. When water vapor accumulates and condenses in the insulation layer, it will reduce the thermal efficiency of the insulation layer, and cause moisture problems such as mildew in the inner wall.
Because of the temperature difference between indoor and outdoor, condensation is hard to avoid. Due to the sealing characteristics of traditional waterproof rolls (such as PE film, asphalt waterproof rolls, etc.), water vapor can not be freely discharged, resulting in the formation of mold.
Therefore, it is very important to ensure the permeability of the building, so that the water vapor diffuses to the outdoor form to achieve natural drying, so waterproof and breathable membrane is the best choice.