潮湿的纤维素在墙壁中
We are in the middle of a deep energy retrofit, and Wednesday before last we had a massive storm roll through. I had a section of west-facing wall that was stripped to the board sheathing that was pummeled by horizontal rain. The wall cavity is filled existing cellulose insulation, probably from the 70’s. When poking a finger into one of the installation holes or gaps between boards, it still feels damp to the touch.
We are wrapping the walls in a self-adhered vapor-permeable air barrier (Grace Vycor En-VS), followed by foil-faced polyiso foam. The interior walls are 100-year-old lath-and-plaster, with an unknown number of coats of paint. My question is:
1) Should we remove the old cellulose and blow in new before wrapping the sheathing, or
2）前进并安装气相渗透剥离的房子包装，以防止进一步的水侵入，但等待一段时间以允许干燥，或
3) Is it safe to move forward with the housewrap and foam installation?
We are in Climate Zone 4, and having an unseasonably warm winter (temperature is 60F today). I appreciate any advice seasoned hands can offer.
-Nathan
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Replies
If believe the moisture that got in was from the rain, and not from vapor drive, the first thing I would do is find out how it got in. I'd start by checking all flashing details, and roof/soffit areas, looking for leaks. You don't want anything to get in after you complete your deep energy retrofit. The big downside of sealing things up for energy efficiency is that you greatly reduce the ability for moisture to get OUT of anything, which is why you want to make sure moisture can't get IN in the first place. This is very important before you move forward with your project.
请注意，Foil面对的Polyiso将否定您使用的空中屏障的蒸汽渗透。箔面是一种蒸汽屏障，如果将蒸汽屏障层叠层（蒸汽延迟器甚至完全蒸汽打开），则最终获得主导组件的蒸汽屏障的性质。所有这意味着您的空气屏障现在只是一种空气密封，它用作蒸汽屏障，与一片聚乙烯没有不同。箔面的聚四诺将阻挡试图通过该可渗透的空气阻挡层逸出的任何值。
在密封后，你会做什么泄漏取决于纤维素的湿程。如果它只是一点水分，我会给它一个干燥的机会，看看事情是否有所改善。如果它在合理的时间（至少几天）干燥，那么你可能还可以留下它，只要它没有任何不寻常的解决。如果它不想弄清楚（高湿度水平，多雨天气等），或者你不能等待，那么拿出旧的东西并放入新东西更好。
I'll stress one more time that you absolutely want to find out how it got wet in the first place and fix that before moving forward with your project though. As soon as you close things up with the new materials, any future moisture problems are going to be much more serious.
Bill
Bill, thanks for your reply. I know how it got wet - we had the siding off, so only the board sheathing was exposed, and had a record storm (85 mph winds driving rain horizontally) that pushed water into the gaps between the board sheathing. The insulation was dry before the storm, and we are adding flashing details as part of the build-out of the wall.
The cellulose is damp but not so much you can squeeze moisture out of it. I think I will go ahead and wrap the walls with the peel-and-stick to avoid further intrusion, but leave that exposed (i.e. no foam) for a week or two for further drying.
I had a very similar occurrence. Rain pouring through old gapped board sheathing before the WRB was fully installed. But we were still down to studs w/o any insulation or interior walls.
VYCOR EN-VS的规范外观为15倍率，允许90天曝光。
I share Zephyr's concerns re: the polyiso acting as a vapor barrier. For my reno, I assumed water will someday find its way into the exterior walls. We allowed for a drying path to the exterior.