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Housewraps and Building Paper: Beyond Water Resistance
Tensile strength, vapor permeability, and pliability are important, too.
在最近的一个blog post，我涵盖了防水屏障（WRB）测试，以在防水性方面将小麦与谷壳分开。但是，一个好的WRB也具有其他属性。它需要坚硬，而不是撕裂，然后将其拉紧并固定。如果水确实进入组件，则需要允许干燥。它需要灵活，能够在不折断或削弱的情况下弯曲。
已起草了新的ASTM“用于机械固定的蒸气柔性板抗耐水性屏障的标准规范”，以解决拉伸强度，蒸气渗透性和柔韧性。
此处介绍的表说明了一些行业代表的一项建议，以简化WRB要求指南。它与ICC-ES AC 38非常相似 - ”防水障碍的接受标准。”该表有几件事要注意。
Table 1: Requirements for Water Resistive Barriers
| Test Requirement | Specimen Type | 测试方法 | Minimum 性能要求 |
|
|---|---|---|---|---|
| Type I | II型 | |||
| 干拉伸 力量或干式力量（选择1） |
(1) as 制造＆（2）根据本标准的A1.2年龄 |
ASTM D 828 for Paper and Felt materials, or | 3500 N/m（20 lb/in) minimum (machine & cross direction) |
|
| 聚合物材料的ASTM D 882或 | 3500 N/m（20 lb/in) minimum (machine & cross direction) |
|||
| ASTM D 5034 (Grab Method) | 178 N (40 lbF） 最小（机器方向） 156 N (35lbF）minimum (cross direction) |
|||
| 防水性 测试（选择1） |
(1) as 制造＆（2）根据本标准的A1.2年龄 |
D 779 or | 10 min minimum | 最低60分钟 |
| 防水池测试（A.1.1节）或 | 没有水通过120的膜传播 最小 |
不适用 | ||
| AATCC 127 except that the specimens shall be held at a hydrostatic head of 55 cm (21.6 in). |
不适用 | No leakage is permitted to the underside of any 标本在300分钟内。 |
||
| 水蒸气传输测试 | 收到 | ASTM E96/E 96M Dessicant Method | 290 ng/（pa•s•m2）（5个perms）最低 | |
| Pliability Test | 收到 | see Section A.1.3 of this standard | 材料 弯曲在1.6mm（1/16英寸）直径的Mandrel上时不会破裂 温度为0 C（32 F） |
|
- 1。两种类型的WRB：I型WRB具有所谓的“基础”防水水平。II型WRB具有所谓的“增强”水平的防水性。这种差异仅反映在防水要求中。似乎I型WRB可能会在干燥的气候下（每年降雨20英寸或更少），而II型是所有其他气候的门票。
- 2。拉伸力量或破裂力：可以从中选择三种不同的ASTM测试方法，但所有的都是材料强度的代理。
- 3。蒸气渗透性：All WRBs must be a minimum of 5 perms; 5 perms is considered to be vapor semi-permeable (Joe Lstiburek classifies materials in the range of 1 to 10 perms as a Class III vapor retarder, based in part on the Canadian General Standards Board approach to vapor retarders). This is good because WRBs should keep out water but also allow drying.
- 4。Pliability:鉴于柔韧性测试的温度，即使WRB是“冷”（32ëšf），WRB也必须是柔韧的。
- 5。老年测试：必须对“接收”和“老化”的材料进行拉伸强度和防水性测试。老年测试涉及润湿和干燥的循环以及紫外线（UV）暴露。
Will these tests and their thresholds help us select high-performance WRBs? A quick check of a number of products (Typar, Tyvek, PinkWrap,雨滴， 和巨型Tex)表明,他们都能通过这些性能tests (although none of these products currently reports the required aged testing results). The only thing I could find that would not pass the new draft standard performance tests is standard roofing felt (often mistakenly called “building paper” and just as often mistakenly used on walls as a WRB—see thisFortifirer资源）。1
So when all is said and done, we are probably back to the “empirical” approach:
- 1.从符合新建议的标准性能测试的WRB开始
- 2.将每个制造商的说明安装在模型墙上，然后让组装在阳光下烘烤数周。
- 3.水测试模型，然后安装覆层。
- 4.再次测试模型。
- 5。If it passes, make sure your crews install the WRB system with the same degree of care and attention to detail as they showed in the wall mock-up.
……………………
1我们可能需要一个关于构建论文的其他博客，弄清或至少试图尝试沥青浸渍的床单上的所有属性和术语。敬请关注。
7条评论
请澄清
这是该网站上WRB的GBA定义：
有时也称为防毒性障碍物，任何墙壁组件的这层都是墙壁壁板的内部材料，形成了液态水的二次排水平面，使其超过了覆层。这层可以是building paper, housewrap, or even a fluid-applied material.
Seems to be some confusion with this post and your comments on felt paper.
请澄清
我的意思是我需要一个关于构建论文和毛毡的博客，正确的卡尔？
在以前的建筑科学博客中，我引用了2006年的IRC，该博客使用了“ Felt”一词而不是纸。更多的混乱。这个主题肯定是下一个建筑科学博客。感谢您的跟踪。
Is asphalt felt a WRB?
Peter,
我必须不同意您的陈述：“标准屋面感觉……[经常]在墙壁上被错误地用作WRB。”用作WRB，在墙壁上使用屋顶毡不是错误。数十年来，它不仅是标准做法，而且由2006年IRC授权。
2006年IRC的R703.2节要求“一层15号沥青，没有孔或断裂，符合ASTM D226的1型毛毡或其他批准的防水屏障，应在所有螺柱上或所有螺柱上应用外墙。”
需要15号沥青。它应安装。任何其他WRB只能用作批准的此要求的替代方案。
Furthermore, manufacturers of ASTM D226 asphalt felt unanimously agree that the product is manufactured for roofs. My conclusions:
1. ASTM D226沥青毡是屋顶的感觉。
2. 2006年IRC在墙壁上要求使用屋顶毡。
3.例外，只要已批准使用这些替代物，2006年IRC将允许使用替代产品替代沥青感觉。
建造纸与屋顶毡
马丁 - 你是对的。并感谢您在JLC和EDU中撰写的参考文献，并提供有关此主题的澄清信息。我没有将新的博客文章专门磨练这两个经常使用的术语，而是在GBA词汇表中添加了用于建造纸张和屋顶的定义，现在这些术语将作为整个网站的弹出窗口可用，包括建立有关该主题的科学博客。
JLC article
任何有兴趣阅读JLC文章的人都可以在此处进行检查：
http://www.dickseibert.com/martin.pdf
Belt and suspenders?
We're starting to use stucco wrap taped to our window flanges and pipe and electrical penetrations and then covered with #15 felt before siding to keep the surfactants from cedar shingles and hardi siding off the stucco wrap.
价格不高得多，我们具有焦油纸的耐用性，带有胶带包裹的气压阻力，以及灰泥包裹正面和焦油纸的后部之间的排水平原。
TMI，真正的问题焦油纸或塑料废话...
I'm not sure how much real world experience you all have in the field, and I don't want to assume. Roofing felt is simply 30 lb. tar paper, as opposed to 15 lb. felt which is meant for walls. What I do know is that the perm rating of tar paper is high, but that when it is quickly covered and protected from sun damage, does a wonderful job as a WRB. Typar and Tyvek in my experience are not that great at water sealing. I do not trust any material that touts vapor transmission ability, and attains it by poking a bunch of visible holes in it. I have seen circumstances where the tannins from wood siding have broken down the moisture resistive properties of the Tyvek wrap and damage definitely occurred due to this. I have also seen water move directly through Typar, and do not trust this material one iota. In my mind, we would be better off trying to create a more vapor permeable kraft paper WRB than the "better world through chemistry" direction. This was more of a rant than direct building science statistics, but I know that there are facts that back it up.
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