11.Weather Barrier and Rain Screen_Aug 12, 2013.pptxVIP

水分阻隔层与防雨幕墙Weather Barrier and Rain Screen第二章Ch.2第12章，附录BCh 13/ App B水分阻隔层定义Weather barrier definition水分阻隔层是在防雨幕墙安装前应安装的一层膜。呼吸纸，用人造纤维制成，或者是外墙纸（沥青浸纸）通常用作水分阻隔层以提供对于暴漏处的冷凝水提供保护。另外，这层膜可以透过水蒸气，这意味着水蒸气可以双向通过这层膜。 A weather barrier is a membrane installed over the sheathing before installation of the rain screen. Either housewrap, made from synthetic fibers, or building paper is generally installed as a weather barrier to provide an additional line of defense to protect the sheathing from exposure to moisture. 防雨幕墙定义Rain Screen definition外墙体外层的防雨幕墙通常包括以下构件：外层包裹，与外饰面形成排水通风的空腔，防虫网，水分阻隔层。防雨幕墙的最初意义在于为外饰面内部和水分阻隔层中形成一个断层。同时，防雨幕墙形成了水和空气的通路，这样可以使外围迅速干燥。A rain screen on the outside of an exterior wall assembly comprises the following components: an exterior cladding, a cavity behind the cladding to drain water and vent to the outside, a bug screen, and a weather barrier. The primary purpose of a rainscreen system is to provide a pressure break between the backside of the cladding and the face of the weather barrier. Additionally, the rainscreen provides a drainage channel for water to escape and for air to flow, which, in turn allows the assembly to dry out.水分阻隔层内容要点Key message on weather barrier?呼吸纸宽为900mm一卷而外墙纸尺寸最大可达3m。呼吸纸透气性很差（可以用于气密系统），但水蒸气透气性很好。水分阻隔层必须铺满整个建筑区域，接缝处必须部分重叠以防水。水分阻隔层多用钉枪安装。如有任何裂口需要用胶带及时修理很重要的一点是，水分阻隔层必须在墙体穿孔处正确密封，如水管、通风口和电力连接处。Building paper is manufactured in 900 mm rolls whereas house wrap rolls vary in size up to 3 m. ?House wrap has low permeability to air leakage (and can be used in an air barrier system) but high permeability to water vapor diffusion. Weather barriers must cover the entire areas of sheathing and must overlap at joints to shed water. Weather barriers are generally installed with staples. Any tears or holes should be repaired with approved adhesive repair tape. It is important that the weather barrier membrane be correctly sealed around exterior wall penetrations such as water pipes, ventilation ducts, and electrical connections. 要点:Key message防