Do I need drywall between rafters and T&G wood plank ceiling?
我读了许多有关未通风大教堂天花板设计的文章。我是一个DIY家伙，正在田纳西州纳什维尔（Nashville）装修1978年的砖砌牧场。我不确定我在哪个气候区域。根据地图，我认为我是4个，但是代码要求似乎是基于3。我认为我的阅读量足以使自己不确定自己。我将雇用所有这些工作，但我想确保做正确的事情以优化我的绝缘材料，不要引起更多问题。我知道有关此主题的几篇文章，但是我还没有发现任何与我的确切设置相关的内容。感谢任何人都能提供的任何帮助。
我现有的情况：
…cathedral ceiling
Asphalt shingles roof
Plywood sheathing
2×8 rafters
R11 fiberglass insulation with vent cavity left between sheathing and insulation (no baffles)
油漆的石膏板天花板
Non functioning ridge vent
What I am considering:
..cathedral ceiling
Metal standing seam roof
2″ of rigid foam
Existing plywood sheathing
Open cell foam cavity insulation (7″ to 7.5″)
Toungue and groove plank ceiling
Do I need drywall between the t&g planks and the rafters? Is there another alternative? Does everything else look ok?
谢谢
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Replies
E.C. Felts,
First, I suggest that you read this article:How to Build an Insulated Cathedral Ceiling.
Nashville, Tennessee is in Climate Zone 4A.
Q. "Do I need drywall between the tongue-and-groove planks and the rafters?"
A. Probably. If you install spray foam between the rafters, you need to have a thermal barrier -- that's code-talk for 1/2-inch drywall -- on the interior side of the spray foam for fire protection. If you want to confirm this requirement, talk to your local code authority.
If you install fiberglass batts or mineral wool batts between the rafters, you should probably have the 1/2-inch drywall as an air barrier.
问：“还有其他选择吗？”
A. There are always alternatives. If you specify rigid foam above the roof sheathing with a minimum R-value of R-15 (for example, 2.5 or 3 inches of polyiso), you could substitute fiberglass batts or mineral wool batts for the spray foam. The resulting roof assembly would be a little more robust (because the roof sheathing would be warmer, and therefore dryer, during the winter) and the entire assembly would probably be cheaper.
So, to clarify...the stack up that I have suggested would be fine as far as moisture goes and a thermal barrier may be required as a firewall? One of my insulation contractors suggested a spray on thermal barrier in lieu of drywall. Are you familiar with that type of product? I suppose the codes official is the one I need to satisfy. I would like to think the contractor would have only suggested the spray on thermal if it meets code requirements. I will start my research on thermal barriers.
感谢您的答复。
您应该与代码执行者交谈，然后再进行屏障上的喷雾剂。如果他们给您绿灯，我想确认不会出现室内空气质量问题。如果您安装了有很多VOC的东西，那将是解决路线的PITA。
E.C. Felts,
抱歉 - 我之前的建议是错误的。我决定重新阅读GBA article on thermal barriers and ignition barriers, and realized my mistake.
According to 2009 IRC R316.5.2, an interior thermal barrier is不是当将喷雾泡沫安装在屋顶组件中并在内部受到保护时，需要用一层舌槽板或胶合板进行保护至少15/32英寸厚。因此，您不需要额外的热屏障；您的舌头板就足够了。