Stability of wall when using exterior insulation
t_barker|Posted inGreen Building Techniqueson
是否有人想知道用外墙构造的外墙隔离层在外墙上的结构完整性？
我假设构建器将窗户和门绑在结构层中可以适当地支撑门。但是，从结构壁上出来的饰面层的重量呢？
例如，用6英寸的螺钉拿起一堵墙，将4英寸的XPS绝缘固定在结构框架/护套上。然后是其他用于防雨等材料的层，最终是水泥板，甚至是石材贴面材料。因此，完成层可以很容易地从墙的结构层出现5英寸。
所有螺钉上可能会有很大的弯曲负荷，尤其是尺寸较少的窗户或其他开口的良好墙。几乎就像5英寸厚的浮墙一样，从结构接触点起，一堆螺钉将其重量为5英寸。
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答复
这是一条经常旅行的路径，具有精心设计的解决方案。有针对紧固件类型，间距，螺柱穿透深度等的规格，具体取决于泡沫 +毛茸茸的厚度和覆层的重量/类型。看：
//m.etiketa4.com/article/fastening-furring-furring-strips-to-a-foam-sheathed-wall
T. Barker，
达纳是正确的。很重的类型的包覆metimes be a problem with very thick rigid foam, but for most foam thicknesses and siding types, this isn't a problem. Just choose the right fasteners for the furring strips, make sure that the fasteners hit the studs, and use enough fasteners.
As Dana noted, you can find more information in this article:“将毛茸茸的条固定在泡沫外墙上。”
NOTE: This post has been edited to reflect an error I originally made calculating the psf of the furring. I still think builders should use caution.
I need to spend some more time on this, but after initial review of several references this issue should not be taken lightly.
当前的工作链接指向几个文档：
1.) Research Report (updated Aug./2018)https://www.drjcertification.org/system/files/drj/ter/node/726/drr130304attachingexteriorwallcoveringsthroughfswood.pdf
2.) Code Compliance Report (updated Aug./2018)
http://www.appliedbuildingtech.com/system/files/files/abtgrr_1503_02_attachment_of_exterior_wall_covering_coverings_through_through_fpis.pdf
Most of the current Hardie siding products combined with 1x4 furring will just barely fall into the 3 psf column in the tables. However, the Hardie Artisan Lap siding will fall into the 11 psf column. Many of the stone veneer products will fall into the 18 psf column in the tables.
So for example, "HardiePlank" siding with 1x4 furring, ignoring wind design requirements for a moment, and just considering weight of cladding. Yes, with specific fasteners you should be good with 4" foam, assuming 16" OC framing. If 24" OC framing you need to be a little more careful with fastener spacing.
但是，如果您使用Hardie“ Artisan”壁板，则进入11 psf列（带有毛茸茸），只有一种特定情况，允许4英寸厚的XPS，并且构建器需要至少使用0.162“直径。指甲，每8英寸，并穿透至少1-1/4英寸的墙壁框架，假设16英寸OC框架。
对于许多培养的石材产品，看18 psf列，只有一种特定情况，即使没有定制工程设计，甚至可以允许2英寸泡沫。
It seems to me that all builders need to pay close attention when using any amount of exterior foam and cladding on a building.
I think Martin wrote an entire article on this topic- most uses screws - here is a link to the Simpson catalog see page 11
Oops here is the Simpson Link
https://embed.widencdn.net/pdf/plus/ssttoolbox/s1whq1ewsi/f-f-f-sdws14.pdf?u=cjmyin
T. Barker，
The fasteners with exterior insulation are mostly in tension, not bending. The insulation, fastener and furring strip form a small triangular truss structure, the load through the screws is fairly small. There is a good report that looks at displacement and fastener loads with various insulation thickness and siding options.
https://buildingsciencelabs.com/wp-content/uploads/2017/11/CCBST-2017-Structural-Testing-Screws-through-Thick-Exterior-Insulation.pdf
很有意思。
I believe this is the full report, which is needed to thoroughly understand the test and results.https://cdn01.rockwool.com/siteassets/o2-rockwool/documentation/technical-guides/commercial/structural-testing-of-screws-through-thick-exterior-insulation.pdf?f=20181004102146
The insulation and strapping create a stiff assembly and take some of the load in compression. Combined with friction resistance between the layers, bending/deflection is significantly reduced. In the range of most cladding loads it's still primarily a bending problem when screws are installed at 90 degrees.
对我来说，大的接管力是：
1.）在大多数覆层载荷（即最多25 psf）的极限内，甚至最多45 psf，在所有情况下，挠度都非常小。我认为可以忽略不计。
2.) Semi-rigid Rockwool is every bit as good as stiffer XPS boards regarding deflection, and insulation thickness between 3" and 12" does not significantly change the deflection either.
3.) Not necessary at normal cladding loads, but ideally screws would be installed at 45 degree upward angle.
4.) If I was going to install 4" or more of exterior insulation I would consider (but probably wouldn't) upgrading my sheathing to 3/4" plywood because of the increased chance of screws missing the framing.
Still need to remember that this research covers a specific case with 0.20" dia. Heco-Topix 8.0x (or equivalent) screws, spaced every 12", 16" OC.
Same with the Simpson Strong-Drive timber screws mentioned in a post above. Substantial screws at 0.22" diameter, recommended 24" spacing for most cases. Although their conditions would exclude Rockwool semi-rigid board (probably incorrectly according to this report).
>半刚毛的岩盘和关于挠度的XPS板一样好，
建筑科学链接显示def低大约30%lection with XPS.
>理想情况下，将以45度向上安装螺钉。
是否担心这样的角度会将大量水引导到护套上？
Not clear to me is if there would be any advantage to adding glue. Less potential for movement against the foam, especially if long term creep reduces compression.
“直径为0.20”。Heco-Topix 8.0x（或同等）螺钉，每12“，16” OC。
必须使用该类型和间距的螺钉意味着紧固件的成本从背景杂物转移到影响房屋预算的一件。
I agree.
The authors said further research needs to be done to assess alternate screw diameters.
> Semi-rigid Rockwool vs. XPS.
Yes, but 30% of what amount? In this application that difference in deflection is so small it does not have any practical impact. So in my opinion, "every bit as good" from a deflection perspective.
>以“ 45度向上角”螺钉。因此，螺钉的头将低于嵌入框架中的螺钉点。因此，从下部到更高。我看不出如何将水引导到护套上。
30% difference may allow fewer or cheaper screws for the same deflection.
Agreed on "45 degrees up towards the interior".
So how do we reconcile this RDH Building Science information with the IRC tables and also with tables from various fastener manufacturers like Simpson SDWS Timber Screws? How would you convince a building inspector what to allow?
最好的是让结构工程师规格细节。那里唯一的缺点是根据工程师的CYA因子，您可能会插入很多螺钉。
I guess I was lucky with my build as the inspector never asked about the details of the exterior insulation and siding.