最小化墙壁组件的风险
I’m building a house in Zone 6 in Ontario Canada. Unfortunately, I only started reading Martin’s articles on risky walls, all the Q&A here and any of Joe Lstiburek’s articles I can find on BSC recently, and am a bit too far into construction drawings and permits to make any major modifications to wall assembly thickness. Indeed, the Code “Compliance Packages” here specify a risky wall construction with R22 + R5CI or R19 + R5CI. A non CI wall can meet code with just R22 stud wall insulation.
我计划在我所吸取的风险之前，在我所在地区的许多建筑和装修中加入R5外部CI。将墙壁更换为双螺柱墙或使用2到3英寸CI需要在这一点上需要太多的返工和城市计划批准;更不用说长期的项目延误。
将R5的一个选择r5可选择使用CDX护套与可排水的WB，然后在WRB上打开1“开放的GPS。如有必要，可以在GPS底部添加脉洞，以供排水。
我的问题是真正有帮助风险，但更多的是在墙壁上获得额外的R5真的值得所有麻烦吗？我的建筑师在不值得的营地。他觉得我应该花钱和努力，如空气密封或窗户。Windows的最小代码为0.28或有效R3.5。我可以获得U 0.15或R7的高性能窗口。
如果我放弃墙壁上的CI，默认墙将是一个2×6螺柱壁，带有R22腔隔离，CDX，带有WRB或常规拉链。
GBA Detail Library
由气候和房屋部件组织的一千个建筑细节的集合
答复
How difficult would it be to upgrade your planed outsulation from the .75” R5 to 2“R14?
Walta
Allan,
您可能已经读过了这一点，但这是一个非常全面的主题概述：https://www.greenbuildingadadadisor.com/article/rethinking-the-rules-on-mimum-foam-ttickness.
既然你没有加拿大答案，我会在它上裂缝，只有在建设科学的背景下，因为我不知道加拿大建筑代码......
In our CZ6, which I think it can be pretty close to yours, we need to install R11.5 CI on a 2x6 wall and R7.5 CI on a 2x4 wall with vapor retarders Class III, or ≥R5 on a 2x6 wall and ≥R3 on a 2x4 wall with vapor retarders Class II.
它可能值得读取2021年IRC表R702.7（1）蒸汽延迟材料和课程。
使用CDX护套带有可排水的WRB或雨水屏幕在任何气候区都是一个很好的主意。我希望我的回答有所帮助。
编辑... UPS，当我在这里写下我的答案时，你有一对夫妇。用两个手指键入
2nd edit: Air sealing should be priority #1 regardless what else you do. Always!
Thanks for the replies. Walta, I would have to change wall thickness which would change interior layout a bit, not a preferred option, my site plan is locked with the city.
Malcolm: yes I read that article and Joe's article on double vapor barriers. We still put 6mil poly before drywall here. Without going too far off topic, these articles have prompted me to choose vapor permeable in both directions. CDX with Siga Majvest 200 WRB and Siga Majrex in place of the poly inside. I think this makes the wall safer in winter and summer. So does the article imply that R5 is safer with this construction?
Armando：谢谢你的信息，距离安大略湖的岸边大约500米，所以有点温和，是的，可能非常接近你的CZ6。包层将是全床和木圈和摇晃的摇晃。我也与我的建筑师辩论一个雪松摇晃壁板的Rainscreen;Obnyke Slicker或压力处理的胶合板捆扎。
我附上了Ontario Code Fyi合规性包的摘要页面，您必须选择一个，没有混音和匹配
我不能遵循你打算建造的墙。但+1还遵守2021 IECC代码中的一个选项，如果您将使用连续的外部泡沫。
没有外部泡沫，壁可以适当地关注普遍比率。
Additional things that generally help: air sealing on both sides, smart retarders on the interior side, plywood on the exterior and higher perm foam (like unfaced GPS or EPS).
Thanks for the references to IRC Table R702.7. Reading through those I found Joe Lstiburek's article BSI-026 They all laughed.... I don't know how I missed finding that one earlier. It would appear using the R5 is acceptable. So the proposed wall construction will be from inside:
drywall/Siga Majrex/batt insulation/ CDX/drainable WRB/R5 GPS/rainscreen/cladding
Joe's article is attached. Hope is OK since it was downloadable.
“我必须改变墙壁厚度，这将改变内部布局一点，而不是一个首选选择，我的网站计划被锁定在城市。”
It is hard to imagine that your setbacks from the property lines are so tight that expanding the outside of the building 1.25 inches in every direction without changing the interior would violate your zoning requirements. If that is true it sounds like you are dancing on the head of a pin and let’s hope the surveyor is on site when they set basement forms.
It seems unlikely the city inspectors will be on site to see and or notice the foam is thicker than planned before it is covered with siding and unnoticeable to anyone without a 50 foot tape measure.
Walta
With 18" setbacks, 1.5" is a lot of space. You never want to be at the point where your walls are over the setback, it only takes one neighbor to come out with a tape measure. Than, it is either committee of adjustments or moving the wall. Neither option is fun.
I understand that some projects make field adjustments that do not comply with approved plans or zoning by-laws in hope that an inspector doesn't notice or require an after the fact variance if caught. I would rather plan everything well and build to comply rather than plan to exceed allowances.
有关于加入R5刚性CI的努力和费用的额外思考的任何人都将其朝向空气密封，窗户或其他升级？
>干墙/ SIGA MAJREX / BATT绝缘/ CDX /可排水WRB / R5 GPS / RAINSCREEN /熔覆
另一个需要考虑的成本/收益权衡would be to eliminate the rainscreen.
It's not too hard to calculate the cost vs energy savings of more R value. But it's hard to put a value on "wall is more robust against moisture".