在纤维素填充墙的内部和外部都在造成蒸汽抗性障碍吗？
马克亨利|Posted inEnergy Efficiency and Durabilityon
Reading the Fine Building Mag artical ‘Designed for Success’ (link below) I noticed the 16″ double stud wall assembly had a layer of spray foam on the exterior sheeting (couple of inches) with the remaining wall filled with dense pack cellilos and closed with a 6mm poly vapor barrier . With the closed cell spray foam and the poly rap I am assuming moister in the wall is not a concern – why? Is this wall type safe in all climate zones including extream cold – we get 8000 hdd with many days sub -40. Why isn’t the due point a consern? Science based feedback would be helpful.
Thanks
标记
GBA详细资料库
由气候和房屋部件组织的一千个建筑细节的集合
搜索和下载施工细节
答复
标记，
我没有看到任何参考内部聚乙烯蒸汽屏障。也许你只是猜测，基于插图？
图中所示的内膜可能是气相渗透 - 无论是将纤维素固定到位的，也可能是“智能”（可变渗透率）蒸气延迟器。
墙板和铆钉/绝缘之间的无疑和未标记的薄柔性层可以被解释为包括吹气网的任何数量的东西。
喷涂聚氨酯泡沫也有多种densities & vapor retardencies. At 2lbs density most polyurethane runs about 1.2 perms @ 1", and would still be as vapor open as a kraft facer on a batt a 3" (R18-R20), and thus not a true vapor barrier. Toward the end of the text on the third page the author mentions a "flash coat of spray foam", which we can reasonably presume would be closed cell, between 1 & 2 perms.
在文本结束时（第3页的底部）他们注意到作者“Steve Baczek是读取质量的建筑师。马萨诸塞州在美国气候区5，因此如果在泡沫/纤维下进行露水点控制边界，他显然没有做。但是3-5级烫发室内涂料的组合蒸汽滞后性+ 1-2型渗透泡沫在气候区中的OSB或胶合板护套的足够的保护5s。（如果壁板回到通风以增强外部干燥，而且它足够好对于我们6区，即使虽然不太符合IRC代码的字母。）
虽然该堆叠不会在加拿大中西部，北安大略省或大多数魁北克 - 柔性层中削减它，但柔性层必须小于1倍（Poly会很好 - 所以智能蒸汽延迟器也会很好）仍然可以使用纤维素填充的护套的内侧上的闭孔的闪光泡沫。气密石膏和“蒸汽屏障胶乳”（约0.5倍乳胶）也可以用闪发泡护套工作。