Wall insulation question
Hi,
We opened two exterior walls in our 1850s farmhouse in upstate NY (climate zone 6) to stop cold air in the winter and prevent rodents from entering the walls. The wall is now more rodent proof and we are moving on to insulating, but I have some questions.
其中一堵墙是一个没有绝缘的棚子，上面有一个地板 - 该墙由（从外到in）建造：1英寸胶合板，薄（约1毫米）的泡沫塑料双面双面w/ foil（一侧穿孔，一侧穿孔在另一个），焦油纸（约1毫米），1英寸木板，腐烂的纸，1英寸木板上，每个木板之间的木板，然后是〜8英寸深螺柱舱。对于这堵墙（8'x 13'），我想到了两个选项：1）8英寸岩羊器，确定性膜，胶带。或者，从螺柱托架后部的刚性泡沫开始 - 用罐装泡沫，然后是岩锅，膜和雪地岩密封刚性泡沫。
The adjacent exterior wall (8×9′) does not have an attached shed outside of it. This wall from outside to in contains vinyl siding, untaped 1″ extruded foam panel, wood lap siding, then a 6″ deep stud bay. Here I was planing on adding R23 rockwool. and vapor retarder. Alternatively, I could also seal the back of the bays with rigid foam.
We don’t want to opt for expensive alternatives on such a small project (e.g., closed cell spray foam).
Thanks – hoping to close these walls up soon!
Dave
Replies
For you shed side:
The simplest way to treat this is to assume the attached shed is similar to an attached garage for a house. Garage walls are treated the same as any outside wall, so in my area, that means interior vapor barrier with batts.
在您的情况下，问题是薄层面对泡沫的薄层。这会产生真正的冷侧蒸气屏障，这在加热主导的气候方面是个坏主意。您的选择要么取出泡沫，然后选择标准的墙件组件（干墙，VB，Batts，护套，壁板），要么添加足够的刚性绝缘层（棚内）以进行冷凝控制。在第6区中，如果您使用R30 batts，则此〜R15。您可以通过使用较薄的烤面包（例如R15 Batt，R8泡沫）来减少泡沫的量，这对于区域6来说仍然是一个很好的墙壁。
Cut and cobble the foam to the inside of the cavity won't work, the foam needs to go on the outside. If you don't want this, about 1.5" of closed cell spray foam would also work. I've used one of the two part DIY kits for this type of assembly before.
For the other wall, you assembly will work fine. Make sure you get the drywall air sealed as you are relying on the lack of air flow and warm side vapor barrier to keep the moisture out of the wall. The existing exterior rigid foam does allow for a bit of drying, so as long as you watch these details, the wall should work great.
P.S.在处理带有不平衡间距和真正2“螺柱的旧墙壁时，我发现最好获得24英寸的巴特，将它们侧面转动并切成湾的宽度。比尝试从侧面修剪1/2英寸要容易得多。
Thanks so much. Maybe removing the outer plywood and then remove the foam would be easiest - should I just put the plywood back as the inside-shed exterior wall, or would another covering be better? Should I also remove that thick tar paper when I remove the foil?
If the plywood is in good shape, you can definatley put it back. Something like densglass or fiberboard would be "better" as it is more permeable, but I don't think you need that in this case.
焦油纸是一张出色的WRB。较旧的纸张往往很脆，很容易损坏，因此您很可能必须更换它。您可以使用毛毡或众多合成房屋包装之一。
Note that he probably doesn't need a WRB inside the shed, though an air sealing layer would still be nice, and of course the wall should be rugged enough to withstand whatever the shed is used for.