Best Insulation Practices in Quebec, Zone 7
我正在帮助一个朋友在魁北克克斯重建外墙，目前没有绝缘。我们将更换腐烂的铆钉并更换浴室窗户，并希望了解绝缘墙壁的最佳方式。我们目前正在考虑封闭的电池喷雾泡沫，内部和胶合板护套，Tyvek，刚性泡沫，1英寸空气空间，然后使用板和板条固定在水平的毛刺条（垂直毛茸茸条顶上允许空气和水分流动）。
这是矫枉过正吗？或者将简单的内部喷雾泡沫安装是否足够，而不会增加大量并发症，如窗户安装（在现在的较厚墙壁上）？使用闭孔喷雾泡沫结合外部泡沫板是否有问题？（一直在阅读一些关于这个的争议）。
你会怎么做?
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答复
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Q. "Are there issues with using closed cell spray foam in conjunction with exterior foam board?"
A. Yes. For a long-lasting wall assembly, it's best if the wall sheathing can dry in at least one direction. That means that if you decide to install rigid foam on the exterior of your wall, you should choose a vapor-permeable insulation (fiberglass, mineral wool, cellulose, or open-cell spray foam) to install between the studs.
有关此主题的更多信息，请参阅Calculating the Minimum Thickness of Rigid Foam Sheathing。
It really depends on the thickness & types of spray foam & foam board. A flash-inch of closed cell polyurethane foam isn't sufficiently tight to qualify as a vapor barrier under Canadian code, but it almost is. (In practical terms it's "as good as..." ). Unfaced Type -II EPS doesn't get there until it's more than 3" thick.
闭合电池泡沫通过铆钉热桥接是浪费的好泡沫。虽然中心腔R可以非常高，但是壁的热性能受到通过框架馏分传导的热量的限制。在2x4腔内的R6 /英寸闭孔泡沫的全腔填充仅为R13纤维素腔填充或R15岩棉将提供的全壁性能增加了大约R2。
Save the foam budget for fatter exterior foam- it'll buy a lot more performance per dollar, and it buys more moisture resilience too. If you put 4" of EPS on the exterior it typically costs less than $2 per square foot, and with a cellulose or batt cavity fill and the described rainscreen gap you'd be at about R26-27 whole-wall. With 3.5" of closed cell foam the foam would cost you over $3 per square foot, and you'd have a whole-wall R of about R12 plus the R value of the exterior foam. With the closed cell foam cavity fill it would take 3" of exterior EPS to hit comparable performance to the 4" EPS + cellulose cavity fill wall.
With R15 rock wool and 3" of exterior EPS (R12-12.5) you would have sufficient dew-point control at the sheathing to build it without interior vapor retarders, and it would still have some drying capacity toward the exterior. With R13 cavity fill you'd make it with only 2.5" (R10-ish), but more exterior-R is always better.
如果您要欺骗这些数字来限制墙壁的厚度，在室内石膏下使用更加蒸气的智能气旋器，例如Cerkainkeed膜在春季和夏季期间不会妥协朝内部干燥，但会限制冬季水分扩散到胶合板护套的安全水平。
谢谢马丁！还有一个问题：采取时间和精力在护套/ tyvek之间创造空域，并计算出的完成楼梯？
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问：“采取时间和精力，在护套/刚性泡沫/ Tyvek之间创造一个空域，并获得完成的房屋榜样？”
A. Usually, yes. For more information on this issue, seeAll About Rainscreens。
The air space is even more important with board & batten siding, which often gets in more rain penetration than clapboards or ship lap siding.
谢谢达纳和马丁....为每个答案有两个问题......
1. Would horizontal furring strips, with adequate kerfs for airflow, be okay... or should I go to the trouble of a base-layer of vertical furring and overlay rows of horizontal over that? Basically will horizontal furring strips only defeat the purpose of the rainscreen?
2. If we went with the 4" of exterior foam, w/rainscreen, I am having trouble visualizing trim details at the top of the wall where it meets the soffit. Would I trim that with an extra thick trim board and run the foam up to that.... or run the foam all the way to the top of the sheathing and put trim board over top of it as well as the siding? Would this area require flashing? How would I create ventilation for the top of the rainscreen..... Any suggestions or visuals would be great.
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除非你谈论的墙是特别暴露于天气（由于刺痛的屋顶悬垂或不寻常的高度），或者除非房子在一个非常暴露的位置（俯瞰海洋的山丘），否则除非房子（俯瞰海洋），否则我认为你不需要两个毛茸茸条纹（垂直+水平）。水平毛刺条将为您提供Rainscreen间隙的大多数好处，并且在雨后，壁板应该易于干燥。
The trim at the top of your wall (the frieze board) can be in the same plane as your battens. Or, if you prefer, you can use 5/4 stock for your frieze (installed on top of the siding boards) and 3/4" (nominal 1") battens, so that the frieze is proud of the battens.
有关排出RIANSCREEN顶部的信息，请参阅以前链接的文章：All About Rainscreens。但请记住，如果您只需安装水平粗发条（而不是垂直+水平），就没有真正需要排出雨屏差距的顶部。
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