I have been soliciting bids for the interior insulation of my current build. I originally spec’d dense pack cellulose in the walls and ceiling and closed cell Lapolla 4G in the rim joists. The dense pack was to be held in place with a netting (smart vapor retarder), 2×3 horizontal furring strips placed on edge which would also create a service cavity for electrical. The exterior insulation is 4” of roofing polyiso on the gable roofs, an even thicker layer on the low-slope roof and 3” of ROXUL on the walls. The exterior insulation thickness was designed to insure that the ratio of exterior to total r-value was at lest 31% (CZ4). The exterior sheathing is Zip. To my surprise, I was able to find subs who have already converted over to 4G. I realize I don’t need CCSF in my rim joists, but none of the vendors will do open cell and trying to get dense pack in that area is difficult. To my surprise, the subs were also using damp spray cellulose and recommending I use that over dense pack even though I would be installing the vapor retarder and furring strips myself.

So now I am contemplating using damp spray as it would solve a few issues for me. First, it would make a netting unnecessary which saves me money and time. I still plan on using a service cavity in the walls regardless of which insulation method I go with. Second, it would solve an issue I have at the ridge in my gable roofs. The collar ties make it very difficult to get netting attached to the bottom of the rafters for the dense pack. Basically I would have to come up the rafters starting at the floor and then go across the bottom of the collar ties. This would put my exterior/total r-value ratio at less than 31% in the exact area I am most vulnerable to condensation. I could use CCSF there, but the downside is that I will never find a leak (it will happen eventually) until it is too late. However, the damp spray would allow me to fill the entire rafter space, even the area in the ridge above the collar ties, with the right amount of insulation without the issues mentioned above, plus more money and time saved by avoiding netting. Lastly, it would be cheaper to use damp spray in the rim joists, obviously less r-value, but with r-12 continuous on the exterior, not sure I am losing much, especially when it comes to the 1st and 2nd floor rim joists. It might still make sense to use CCSF in the basement rim joist.

现在为了我的关心。潮湿的喷雾将在组件中增加很多水分。我不喜欢向OSB添加水分，我相信Zip护套小于1 pers（我认为他们为OSB做广告1.2，但不要说涂层的内容）。另外，我的外部屋顶绝缘材料已经在屋顶上的外部干燥。好消息是房子现在干燥，窗户已经安装，所以我可以在天气有利于干燥的情况下打开，我可以在9月这样做，通常湿度较低，我可以在安装安装后的一个月后等待一个月绝缘以安装干墙。

My gut is telling me that damp spray throughout would be be the best choice given my situation. Thoughts?