Application of House Wrap in Timer Frame Structure
In the past ten years, house wrap has become an important part of buildings especially for timer frame structures.Wrapping the house structure with house wrap helps resist water penetration, moisture and air infiltration.Therefore, if the siding of the house is the first protective layer, the house wrap is the second protective layer of the house.
The unique micro porous structure of the house wrap can resist the penetration of air and water, while allowing the internal water vapor to diffuse out of the wall structure, helping to prevent the formation of mold and rot.Neither vinyl, wood, plaster, brick, nor composite siding can completely prevent air and water penetration.In this respect, the siding of the house can only play an ancillary role, and the key to improve the comfort of the house is on the house wrap.
The thermal resistance of the insulation is measured when the air in the insulation remains stationary and the insulation itself remains dry.The U.S. Department of Energy estimates that nearly 40 percent of buildings' energy losses are caused by outside wind-driven air infiltration.The opposite pressure between the inside and outside walls causes heat and cold air to seep out through the building's walls, ceilings, door sills, exterior wall joints, top plates, electrical outlets, and crack gaps.When air penetrates in, it causes temperature changes that require heaters or air conditioners to work harder.Fluctuations in temperature can also reduce comfort level, making occupants feel too cold or too hot.Reducing air penetration can increase building comfort level.
Insulation can help improve a building's R value, but it is only marginally effective in reducing air penetration.When air penetrates, the thermal resistance itself can be reduced to 60% than before.Adding thicker insulation won't solve the problem.It only works if the air is kept out.
Proper application of waterproof membrane will help reduce air permeability, maintain R value, save energy, reduce heating and cooling costs and create more comfortable internal living space.However, the better a building is sealed, the more likely it is to have problems with moisture escaping.This can lead to mold and rot problems inside the house.Therefore, effective management of moisture is critical.
Water and moisture enter the wall system in two main ways:
Rain and snow can cause a lot of water to enter the walls, and if it doesn't dry out in a certain period of time, it can increase the moisture content of the wood to more than 30 percent and lead to decay or mildew.
Water droplets form when air flows from the warm side of a wall to the cold side.Warm air contains more water vapor than cold air. When warm air passes through a wall to cool side, water vapor cools and condenses into water droplets.The condensation temperature is called the dew point and this phenomenon is called condensation.When there is a significant temperature drop at the wall, water droplets will form inside the wall cavity.
In winter, the location of condensed water is usually on the inner surface of the outer sheath panel.Because water vapor in the air usually condenses and accumulates on the inside of the outside wall panels.In hot and humid areas, air flows from the outside to the inside.The warm and moist air flow from the outside will condense in the wall cavity on its way to the cool air flow produced by air conditioning inside. Breathing membrane is a kind of breathable membrane with micro pores, which can let out moisture inside the wall, help the wall dry and avoid damage.
Water vapor transmission rate determines the ability of water vapor to pass through a material.The higher the transmission rate is, the more "breathable" the material is, the more easily water vapor can pass through the material.Those with a transmission rate of less than 15g/m2.24h are called vapor retarder, because such materials have a very low water vapor transmission rate and essentially do not pass through.Good waterproofing membrane can achieve a transmission rate of 1000 g/m2.24h, with very good breathability, allowing water vapor to pass through freely.
Waterproofing membrane is a kind of magic membrane, which is not only a vapor barrier, but also a insulation layer.It is a product that worth your choice.