可怕的蒸气屏障问题
你好，
首先，让我说我几乎阅读了这个网站和许多其他蒸气屏障，但仍然感到困惑，或者过度思考，因为我是工程师，这就是我们所做的。似乎答案是案例基础的一个案例，因此在这里。
I want to finish part of my walk out basement for a play room for my kids and i am concerned with mold/rot problems in the future if not done correctly. I live in central NH which is climate zone 6 and the house is not Air conditioned but is heated and the basement will be heated with a pellet stove.
The room will have two exterior walls both of which are 4 foot of concrete and 4 foot of 2×4 construction with unfaced batts. the make up of the house is vinyl siding, house wrap, osb, 2×4 construction with unfaced batts, currently there is moisture behind the insulation on the interior side of the osb (which scares me)
我想完成一堵墙，并消除混凝土步骤，因此我的计划是用牛皮脸替换未取代的巴特，或者使用6 mil poly蒸汽屏障，然后用刚性泡沫拆卸墙壁，即使用混凝土延伸，然后运行从地板到顶部密封的刚性泡沫，将其在未裸浆中的2×4墙壁上构成2×4的墙壁。
the second wall would have a shelf so it would just be vinyl siding, house wrap, osb, 2×4 framed wall with kraft faced insulation or unfaced batts with vapor barrior then sheet rock.
我关心的是能够干燥的墙，如果我不使用蒸气屏障，我的其他选择是什么，喷雾泡沫不在预算中。
also how should i insulate the rim joist.
对不起，第一篇文章很长，但我想获得尽可能多的信息
事先感谢您的所有帮助
Never mind on the rim joist, just read the question a few below mine, thanks
GBA细节库
由气候和房屋部分组织的一千个建筑细节的集合
Replies
In zone 6 a wood sheathed wall without exterior insulation to raise the temp of the wood sheath requires something tighter than a class-III vapor retarder (such as interior latex paint), even with back-vented siding such as vinyl. (In zone 5 you could have gotten away with it.) Kraft faced batts would be adequate if air-tight, but it's nearly impossible to reliably get air-tightness with kraft facers. Unfaced batts are a code violation unless you either put air tight wallboard with a "vapor barrier latex", (about 0.5 perms), or air-tight 6-mil poly (0.05 perms) or a "smart" vapor retarder such as Certainteed MemBrain or Intello Plus (variable permeance). The smart retarders offer the most resilience, since they inhibit wintertime vapor diffusion, but becomes vapor open whenever the assembly has enough moisture to make the RH inside the cavity more than 40-50%, increasing the rate at which it can dry. See:
http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_7_sec002_par025.htm
Building the studwall portion out to make it flush with the concrete works- use unfaced EPS, which is still about 1perm @ 3", which is the edge of class-II vapor retardency.
For the concrete wall section you can skip the interior vapor retarder if your floor to ceiling foam is at least R7.5 without any risk at all, but since there isn't wood between the new batts & foam you can actually cheat that a bit- the stud edges are still warmed due to the higher thermal conductivity of the wood- it's not exactly the same situation as with a wood sheathed assembly. With 1.5" of EPS you'd be at R6.3, which would be just fine with unfaced R15 rock wool, even without interior side vapor retarders. But if you're nervous 2" (R8.4) would give you margin.
气密性比蒸汽retarden更为重要cy, and under NO CIRCUMSTANCES should you put inteiror side polyethylene, which could trap ground moisture in the assembly at the below-grade sections. A smart vapor retarder would be fine though, and may be needed if you use only an inch of EPS between the studs & concrete on above grade concrete.
将EPS的底板放在2x4 Studwall的底部板下，作为热和毛细管断裂。也。
因此，我可以用三英寸的EP省略多个屏障？膜在哪里可用？
http://foursevenfive.com/
Would it be beneficial to caulk between the studs and OSB in all the exterior bays and between the concrete and sill plate?
膜可在我当地的Menards及其网站上找到。会猜测其他大框有它或可以订购。
理查德.... 475似乎没有携带它。根据他们的Intello价格，即使他们确实携带了价格，也将超过Menards的价格。
Matthew,
要记住的最重要的事实是：将内部水分远离墙壁组件，您可以做的最重要的事情是注意气密性。这些层的蒸气渗透并不重要。
也就是说，您不希望墙壁组件中任何地方的聚乙烯。
One more point: You wrote, "The second wall would have a shelf so it would just be vinyl siding, housewrap, OSB, 2x4 framed wall with kraft-faced insulation or unfaced batts with vapor barrier, then sheetrock."
Even if you eliminate the vapor barrier -- and you should -- this is a particularly bad wall because it is so poorly insulated and because it includes the worst kind of insulation (fiberglass batts) ever invented. The wall is thin and there is no provision or reducing thermal bridging through the studs.
如果我是您，我将通过切换到密集包装的纤维素或包括连续的刚性泡沫或两者层来改善这堵墙。
Matthew,
Q. "Would it be beneficial to caulk between the studs and OSB in all the exterior bays and between the concrete and sill plate?"
A. Yes.
非常感谢Martin，我将在各处消除Poly，专注于空气紧密度，并在“坏墙”中加入一英寸半的刚性泡沫
Foundation Insulation Effectiveness: Basement building science
明尼苏达大学扩展的寒冷气候住房协调员帕特·赫尔曼（Pat Huelman）讨论了与绝缘基础墙相关的问题。
https://www.youtube.com/watch?v=kwn0Vjw_ji0
Did you watch minute 24 on... regarding foam instead of batt being better... or better yet (exterior foam). Or minute 29 regarding spray foam on the interior being one of the least risky?
His comment regarding the moisture in rim joist being most related to moisture of foundation wall was odd... since most new houses for the last 20yrs that i have seen have a complete sill seal - which prevents moisture drive into bottom plate.... but i suppose his research didn't look at any particular style/year of home.
尼克 - 泡沫状的窗台密封不会使毛细血管休息得很好，甚至没有混凝土和木材之间合理的蒸气延迟器。它确实需要EPDM，重型聚乙烯板，钣金闪光或其他一些真正的蒸气屏障才能从粉底窗台上分解混凝土。
更糟糕的是，廉价的泡沫式垫片通常不够厚，无法真正应对大多数新结构中的粉底上衣的草率，甚至不提供其设计的空气密封用途。它们基本上是“总比没有好”，但是要获得良好的空气密封需要更平坦的粉底上衣和/或更合规（高度蒸发的）EPDM EPDM窗台垫圈。
oh - no doubt they are not a airtight option - like say EPDM gasket with super flex tape on the outside sheathing as well. In-lieu of a good gasket/tape seems like most modern homes around here are then spray-foamed interior to seal that whole mess up.
但是，我必须想象，一年中的大部分时间里，位于块墙上的2x6将具有更高的水分含量，而不是在便宜的凹槽聚乙烯泡沫垫片上设置的2x6。（.25“）？与多板相同的低pers材料？
我猜我所见过的任何地下室的所有内墙都只是在平板上绿色...我在Preplan上完成了矿山，正计划使用Sill Seal来触摸地面。...不值得帽子休息？我看到BSC确实建议使用该产品作为框架地下室壁时的帽子断裂和热中断。所以我会坚持我的计划。
达娜，
感谢您解决关键细节。