在4A中对双螺柱的水分问题？
Hi all,
首先，这是一个很棒的网站！我一直在阅读超绝热房屋上的所有内容，该网站是一个巨大的帮助。
We are in the planning stages to build a new home (which we hope to be “THE” home that last the rest of our lifetime). We would like to be as efficient as possible with energy use, as well as from a construction cost standpoint. I am willing to pay extra for a system that will pay off down the road, but also don’t have an unlimited budget (who does?) so I have to be smart where we spend our money. I live in central KY, which is zone 4a, so I would like to build a “Pretty Good House” with R-30 walls and R-60 attic. I also want a brick exterior if that matters.
我已经读到了双螺柱墙壁与传统框架的利弊，并在外部添加了刚性泡沫，并来回摇摆了我所在地区最好的泡沫。我已经读到，双螺柱似乎比在外部上的刚性泡沫便宜一些，并且更容易安装窗户，门和固定装置（例如窗户，门和固定装置）。但是，我担心水分积聚。我知道4A区没有太多关注，但是人们对人的意见似乎也有所不同。似乎一致认为刚性泡沫不会受到伤害，对于4A区，任何泡沫的厚度都足以控制水分。但是，我发现的那些文章说，4A可以接受泡沫板的任何厚度，只是在谈论传统的框架技术，而不是双螺柱。我认为我没有发现一篇文章明确地说，对于4A的双螺柱，外部泡沫绝缘不是必需的。
因此，要正确地……对于4A区，如果我使用双螺柱墙壁结构，我还需要在外部安装刚性泡沫板吗？而且，如果我这样做，这是否可以减少双螺柱结构的成本节省，以至于我不妨使用几英寸的外部泡沫来传统的2×4或2×6？It seems like going double stud PLUS rigid foam board on the exterior will be way more than the R values I am needing for my area, but I can’t figure out if that is still cheaper than going 2×4 or 2×6 with 4″ of exterior foam.
任何帮助将不胜感激。（我也有一个关于HVAC的问题，但我会再保存它）。
GBA细节库
A collection of one thousand construction details organized by climate and house part
Replies
粘土，
外部刚性泡沫的使用与双螺旋壁不兼容。
双层墙壁需要干燥到外部。泡沫外的墙壁不能干燥到外部；它们被设计为干燥到内部。
You need to choose which way to go -- don't mix-and-match these two approaches.
If you plan to install brick veneer, I strongly suggest that you frame your walls with 2x6 studs and install exterior rigid foam. Rigid foam is a great match for brick veneer, since it protects the studs from water intrusion and stops inward solar vapor drive in its tracks.
Thanks for the reply Martin! I was hoping you would respond. I have been reading your articles and was hoping to get your opinion. Sounds like the clear and obvious choice is rigid foam over 2x6 studs.
The brick veneer also has a severe thermal bridging factor to contend with at the top of the foundation- it'll undercut the high thermal performance of the walls if you don't take measures to deal with it:
//m.etiketa4.com/sites/default/files/Exterior%20basement%20insulation%20is%20incompatible%20with%20brick%20veneer.jpg
Pouring the foundation with a ~1' stepdown to the exterior side of the framing to support the brick, and running the rigid foam in the cavity all the way down to the step helps. Then insulate the foundation on the interior side with rigid foam, then over the top of the foundation sill as well. You still have a thermal bridge at the band joist, but it's a fraction of the size that it would be otherwise.
这就是它在平板上的外观，并在坡度梁中一步一步：
http://www.buildingscience.com/documents/insights/content/bsi-059-slab-happy/images/bsi059_figure_04_web2.jpg
（找不到一个非常出色的完整版本的照片。）
You can also deal with this by stacking autoclaved aerated concrete blocks (which are insulating) under the foundation sill and insulating on the interior with rigid foam, but it's a somewhat messier build.
带有2x6的墙壁，带有吹牛的纤维素和3英寸的箔纸polyiso，最终将带有您要寻找的〜r30的全墙性能。您必须将polyiso的底部边缘远离混凝土或'LL Wick水分（即使是1/4”的缝隙也足够好，但是您也可以放下1英寸的EPS或其他东西。）
这种类型的墙壁的一个普遍问题是找到可以容纳那么多泡沫的合适砌体关系。那里有一些公司开始解决这个市场（但我没有使用过任何公司）。使用3英寸泡沫，您可能需要在放置泡沫之前使用固定在框架墙上的类型，这样您就可以确保它确实与螺柱绑在一起，因为要错过钻头的螺柱 -通过泡沫变得越来越浓。例如：
http://www.h-b.com/index.php?main_page=product_info&products_id=106
(There are others...)
Thanks for the extra advice Dana. This surely helps. If I am looking at the diagram correctly, it look like the rigid foam extends down the exterior wall and onto the foundation and stops just above the top of the step. Correct? What about the white block that sits on the step under the brick?
我喜欢look of a stone veneer foundation (aiming for the house to look like it was built in the 1800's). I spoke to the builder about this and he mentioned needing to have a stepdown on the foundation for this, so it sound like this might not interfere? I assume the insulation would need to go between the stone veneer and the foundation it is sitting on? Can this sit below grade?
Consider thin brick, ! It is 1/2" thick bricks that are "glued" to the walls. I plan on using thehttp://ambrico.com/system with NO exterior sheathing. The outer stud wall, of the double stud pair,, after installing insulation, will be covered with "Tyvec" then a layer of "Greenguard DC-14 (which serves as a ventilated drainage plane as well as blocking solar driven vapor) , then the Ambrico metal substrate panels, brick & Mortar. Using thin brick won't save much money but it allows thinner walls.
Jerry,
我不确定我是否同意您的房子没有墙壁护套。听起来像金属基板面板被用作护套。
This is a proprietary system that I am not familiar with. I would advise Clay and other GBA readers to investigate the system thoroughly before considering its use.