Basement wall fire blocking material?
Martin’s basement wall insulation article is a classic that I constantly refer to when planning my basement renovation. The main thing missing from the equation, however, is fire blocking. As I understand it, fire blocking generally needs to penetrate through any foam insulation all the way to the concrete. This presents issues with thermal bridging as well as compromising the air barrier and vapor retarder layers that the foam provides. What’s the least bad choice? Mineral wool? Pressure treated lumber? Paperless gypsum board? Perhaps with the latter two, their “buried” portion could be painted with vapor barrier paint to keep them a bit more dry?