如何最好地防止桁架增加空气泄漏？
我正在建造一个新家，并试图确保我的石膏板天花板密封。我已经读到有关桁架升降机有时会在内墙顶部形成裂缝的情况，这会打败我的空气密封工作。
我将安装桁架夹，以使桁架在墙壁上方漂浮，但是我试图决定如何最好地将天花板干墙固定在室内墙壁顶部，同时仍允许桁架根据需要移动。关于使用什么的建议？
另外，建议不要将天花板干墙固定在内壁约16英寸内的桁架上，以使干墙弯曲而不是破裂。但是，在桁架中间的房屋中央沿着房屋中央延伸的42英寸宽的走廊如何工作？这只会允许螺钉以10英寸的宽度固定在走廊中心的10英寸宽度中。听起来不正确。
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答复
黛布拉，
在如此小的区域中，您需要稍微减少无螺钉区域。我会把它们保留回12英寸，而不是18英寸。边缘由墙板支撑，因此不会下垂。
If you do get the odd crack at the intersection of wall and ceiling, it's easy to fix with paintable caulk.
从最少到最实用的三种选择来消除桁架提升问题：
1）理想情况下，您将以某种方式将整个桁架放在阁楼绝缘的上方和外部。
2）将阁楼作为地板平台上的阁楼将其置于胶合板/OSB的顶部托梁上，然后戴上桁架。
将板块胶带胶带，让它们成为空气屏障。然后，您不必担心石膏板，并且获得了服务腔作为奖励，您可以将其用于嵌入式罐头罐头的含量。
3）显然由于某种原因而有帮助。我不确定为什么单层的绑带会起作用（垂直的双层具有偏移量当然应该像减震器一样起作用），但是这些家伙说的是：
https://www.finehomebuilding.com/1998/09/01/dealing-with-with-truss-uplift
还有一个想法：将桁架作为正常安装，在桁架底部安装空气屏障和蒸气阻滞剂，然后将服务腔框架下方的服务腔 - 边缘的2x4s为接线和固定装置提供了足够的空间。
我们遵循迈克建议的技术。我们这里有详细信息：
https://kimchiandkraut.net/2017/08/16/ceiling-details-air-sealing-4/
我们进入了第二个冬天，到目前为止，桁架隆升没有裂缝。
To answer your question in my opinion , poly if you are using it. Wrap it around the wall ceiling intersection. How big are your trusses ? 30 ft is a lot bigger than 24 ft. 36 ft are big. The longer the bottom chord the more you should worry. You could design your building to have shorter trusses. Trusses are a triangle and if the bottom chord gets shorter than the top chord they start rise. The 1970 is the first time I personally saw this. We quickly learned not to design trusses with a center post. This helped a lot. Maybe only because the bottom chord could bend a bit more in the middle. I think lots of ventilation is the cheapest answer. Keep the top and bottom chord the same moisture content. Lumber does change in length with different dryness. Not much but in a truss to much.
是的，中心帖子似乎更糟糕的情况，因为那些连接和弦的人确实是阻止事情沿着飞机统一发生的原因。有点像弓箭。除了顶部的和弦延长和底弦缩短外，还需要在中心附近的限制性连接。（也许很明显，这是为什么通常不陈述的原因；否则基本上只是afters）
（编辑）：我没有观察到这种类型有任何不同的看法，我只是在迈克的观察结果……消息人士似乎说桁架类型并不重要。由于三角形将提供与单个垂直成员相似的约束，因此可能并不重要。也许很少。无论哪种方式，无论如何，它都可能与宏伟的计划无关）。
As a woodworker I've always found truss uplift confusing since we are taught wood doesn't shrink/expands hardly at all along its length. I think this becomes an issue with long spans (certainly much longer than furniture!) and with construction grade wood more likely to have abnormal (compression and juvenile) wood that exhibits increased longitudinal shrinkage.
我喜欢迈克尔的建议，以实现强大但简单的解决方案。
如果仅依靠石膏板，除了将紧固件放在靠近墙壁附近的紧固件外，使用某种鳍来捕获天花板干墙并将其紧紧固定在墙壁干墙上可能会有所帮助到顶部板（但不适合天花板） - 或者它们也使夹子和乙烯基角也可以发挥相似的功能）。
迈克尔，您是否知道通常可以在3/4英寸或1.5英寸的天花板上运行罗梅克斯，只要它们不太接近框架'可能获得指甲和螺丝渗透'的框架'？
Thank you for the suggestions. There's a limit to what I can do since the house is mostly framed already. Our trusses are 28 feet long. No center post, as we had them frame the trusses to allow for an elevated walkway running down the center of the trusses. We're finishing the interior wall framing next week.
我们可能最终不得不将一个天花板绑在一个颤抖的毛茸茸的条带上，因为主房间中的至少一个桁架比其余的桁架低1/2英寸（不要问我分包商是如何设法做到这一点的！）。但是，在房屋的其余部分中，我可能会沿着内部墙壁板板使用干墙夹，以将天花板干墙固定在适当的位置。
我有一个租赁物业，有不良的桁架提升问题。我确实在天花板的某些区域（最后18英寸左右）取下了指甲，并在阁楼上安装了砌块，该阁楼连接到隔板墙的顶板上，我的底面是我将天花板干墙拧入的。
HOWEVER---what really made the difference is something Mike mentioned in reply #4: ventilation. Right at the time I did the work I mentioned, I had a new roof installed. Crucially, the old roof had no ridge vent, just gable vents to exhaust the intake from the soffit vents. I had a ridge vent installed with the new roof. Voila, no more truss uplift, as evidenced by the disappearance of the seasonal cracks in all areas, even in the areas I had not removed nails from.
显然，在旧情况下，顶部的和弦变得过于湿润，膨胀，并通过剪刀的织带或支柱将较干燥的底部和弦与它们一起拉起。
So yes, good ventilation is vital. And even more so: air sealing the ceiling up against the attic. The devil is in the details.
Thanks for sharing your experience. Fortunately, my attic will have excellent ventilation. So, hopefully that will help.
嗨，黛布拉---
You are quite welcome. And the air sealing bit is key: much more moisture comes via air leaks as opposed to diffusion through materials. Thorough airselaling plus good ventilation, and you likely won't have a problem. Good luck!
Exactly. The small things you need to do to mitigate truss uplift - clips, keeping fasteners back from wall/ceiling intersections - assume it will be a minor problem. If they are not effective, something much bigger is in play and needs to be addressed.
I'd have no problem leaving 18" to first screw in 42" wide hall. The ceiling board is installed first, hopefully within 1/4" or so of the walls. Then wallboard is pushed up tight to the ceiling (top course first). Once that joint is taped and mudded, it's not going anywhere.