Confused about new roof / decking / insulation job
Hi, my name is Todd and I’m very confused about what to do. My insurance company has agreed to replace the roof, including the decking (sheathing), and ventilation, in my cape cod home in Dayton, Ohio. I have a refinished, vaulted second floor, with a small attic peak. All of this was there when I bought the home 3 years ago (I think it was done in 1998). Thinking this would be a chance to improve the insulation I began to investigate what to do. Now I am completely baffled, both online sources and contractors have given me such divergent advise.
这就是我对房屋结构的了解。
我有沥青带状疱疹
I have no soffit vents.
我有海龟通风口和山墙通风口。
afters是2乘6。
I have R-19 batts crammed in the rafter along with styrofoam baffles (approximately 2 inches in depth). Thus the batts are compressed to roughly 3.5 in. This material runs from the knee wall top to the small attic floor and peak area (3 ft or so triangle).
我似乎在膝盖下方的地板a子上有更大的松散绝缘材料，并假设我在小阁楼上做（我无法接触）。
我不知道该怎么做。感谢您的建议。
Thanks,
托德
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
答复
R19是OH的相当crummy-r和子代码R。
“正确”的事情是要关闭通风口，当新的屋顶甲板下降时，将纤维素从外部吹入通风口，完全填充了（2x6？）rafter after after after after bay大约R20。然后在屋顶甲板上方，在新的屋顶甲板上涂上适当的滑动材料，3.25英寸（R20）纤维面屋顶polyiso，用外部OSB Nailer甲板固定在适当位置24英寸O.C.，带有＃30毛毡和带状疱疹或任何应用于钉子甲板。
另外（但更昂贵），可以将泡沫固定在适当的位置，2倍毛茸茸的螺丝螺丝拧到24英寸O.C.的木螺钉，并使用soffit-to-ridge通风系统将钉子甲板拧紧或钉在毛茸茸上在钉子甲板上。如果有很多臀部/山谷，值得分割毛茸茸以允许全面通风。这具有降低冬季钉子甲板温度的优势对于在终点屋顶中出现的任何未来泄漏。如果没有通风的钉子甲板，任何未发现的泄漏都可能会破坏钉子面板，甚至可能使泡沫面板饱和。但是这两种方式都完成了。
R20 ISO的材料成本加法器约为每平方英尺2美元，但是您的中心腔含量约为R40，但是由于外部泡沫被the绕被afterters损坏，因此性能将等同于R45之类的东西-r50在地板托梁之间应用，这更像是代码。在屋顶甲板上方的R20的情况下，您不需要内部蒸气屏障来保护甲板免受内部水分驱动器的侵害，并且它对美国气候5（Dayton在5区）完全符合IRC 2012：
http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_8_sec006.htm
The air leakage behind & through kneewall attics is usually atrocious, and by making the roof deck the primary air barrier and blocking the vents, it brings those mini-attics fully within conditioned space, and your whole-house air tightness numbers will be much improved, and with the roof deck now partially inside the insulation layer, it runs much warmer, and minor air leaks from the interior into the attic space through those kneewalls don't turn into a moisture & mold problem.
In some locations (like mine) there are companies that reclaim roofing foam from commercial building demolition, which cuts 2/3-3/4 off the material price. If you need a truckload, insulationdepot.com delivers, for a price. They have a facility in WV, not sure about OH. In my neighborhood I have multiple vendors pf reclaimed foam, some of whom advertise on craigslist. YMMV
除非另有标记，否则假设再生纤维面向的屋顶ISO为〜r5.5/英寸的厚度，因此3.5“也是最小厚度，即使大多数处女股票为R20 @ 3.25”。（R6/英寸）。放置更多的东西永远不会受到伤害，但是在6英寸或更高的情况下，螺丝长度有点笨拙，尤其是当您使用通风的钉子甲板方法时。
嗨，达娜（Dana），感谢您的详细回应，这非常非常有帮助。我正在研究详细信息以完成此操作。非常感谢。
最好的托德
詹姆士，
You have two choices: you can build an unvented roof assembly or a vented roof assembly. Either approach can work, as long as you get the details right.
至少,你必须确保你的insulation is thick enough to meet code requirements. You can't do that with 2x6 rafters, so you will have to make your roof thicker -- either by adding insulation on top of your roof sheathing, or by building down your ceiling to provide more room for insulation.
本文清楚地说明了所有选项：如何建造绝缘大教堂的天花板。