如何隔离para和弦单桁架24英寸深度
Noddon|Posted inEnergy Efficiency and Durabilityon
如何在3：12斜坡上隔离平行的和弦单桁架天花板？屋顶将是胶合板护套上的金属。另外，哪种类型的底层适合胶合板护套上的金属屋顶？
GBA细节库
A collection of one thousand construction details organized by climate and house part
搜索和下载施工详细信息
Replies
With low slope cathedral ceiling, you can use blow in insulation. It is good to get some baffles (could be stapled cardboard) against the top chord to make sure the ventilation gap stays open as it might be hard to see while filling the roof. Make sure the insulation weight is bellow the limit of the ceiling drywall so it won't cause bowing.
Looking at the drawing, you can probably fill it from the outside from the upper side before the siding goes on. This would let you install the ceiling before the insulation goes in.
我喜欢您的建议，一旦天花板建造天花板，就从外部吹到纤维素进入腔体。
//m.etiketa4.com/question/zone-5-envelope-envelope-eclosure-parelalle-chord-chord-truss是一个开始
如果您使用一个24“桁架和完全密实充填智慧h cellulose (3.5 pounds per cubic foot), that adds 7lbs per square foot dead loading at about $0.40/lb = $2.80/sqft on insulation for R-91 (about the same cost as two inches of closed-cell foam). Use either extra strapping and drywall screws on the underside to help hold that weight, or plywood/osb.
如果您要像灯光灯一样在天花板上运行东西，而纤维素会有所帮助泄漏，最好做干墙（或放下其他一些内部空气屏障），然后继续前进和毛皮在天花板的底面上有另一层干墙的服务腔。总体而言，大教堂的天花板屋顶非常敏感且难以进行故障排除，因此消除涉及空气泄漏的潜在故障点是一种便宜货。
一点点：我的理解是3:12是某些类型的金属屋面的最小值，此时问题开始出现。仔细选择金属屋顶（密封剂，焊接，接缝）的类型，并考虑使用4:12或更高的金属屋顶，可能会更便宜。
谢谢您的意见！我最初考虑了4:12的斜坡，但在考虑额外材料的成本时改变了主意。根据建筑密码和金属屋顶制造商，3:12是裸露的紧固件金属屋顶的最小有效坡度（并满足卑诗省的建筑代码要求）。无缝的金属屋面对于材料和劳动力密集型也更加昂贵。
等等..“裸露的紧固件金属屋顶？”
I like your trusses and would leave a 3" ventilation gap, but don't use exposed fastener metal roofing..
Nodden,
Snap-lock roofing is more expensive, but much less labour intensive and easier to flash than exposed fastener panels.
I have the exact same truss and am still deciding how to insulate it.
Batts will leave a lot of gaps where the truss "ladders" are. Blown-in seems like the way to go.
我用玻璃纤维吹来玩耍，因为重量将小于纤维素。无论哪种方式，都计划离开至少3英寸的气隙，因为它是由桁架深度提供的。
Fiberglass and cellulose insulation do not stop air movement because the materials are porous. So you'd somehow have to separate the ventilation air, from the insulation to get the 100% of the r value.
蜘蛛玻璃纤维会在爆炸中射击，以阻止对流和玻璃纤维内的空气运动？
Mike,
纤维素不需要分离就可以停止风吹。这是一个关于吹玻璃纤维是否做到的悬而未决的问题。
Thanks for the clarification Malcolm. I'm surprised no one mentioned the recommended flash and batt on the bottom and three layers of insulation and another layer of plywood or battens for the roofing. But the OP's cellulose with air space "should" work also and be easier imo.. I wonder if you could drape house wrap loosely from the rafters and tie the space to the soffit and ridge vents.. Or more elaborate, fill 24" space full of insulation, seal with house wrap and install sleepers for the ventilation space then battens.
Mike,
我认为475建筑物暗示了一个类似于Y0U所描述的组件。它们用可渗透的膜覆盖桁架的顶部，然后在护套前将板条安装在桁架的顶部和弦上。听起来像是一个曾经建造的好系统，但我不是一个人渴望成为船员到处都是的船员。
马尔科姆（Malcolm），我们在Ecocor工作时会定期使用该系统 - 这比您想象的要少得多。在失踪步骤的情况下，高质量的膜可以支撑一个人的体重。但是您可以看到并感受到the子，因此很容易添加临时的脚趾板。就是说，当我使用该细节进行设计时，我从建筑商那里得到了强大的推杆，所以这些天我什至不打扰。选择你的战斗...