I'm working on a house built in 1992 in Nebraska (climate zone 5) that has exterior walls with asphalt covered fiber board sheathing. I'd expected the asphalt be on the exterior of the wall cavity, but as shown below, it is facing the interior. The wall cavity was fulled with blown fiberglass insulation (BIBS) with poly and drywall on the interior side of the wall cavity. The exterior of the fiber board sheathing was tyvek home wrap and hardie board siding. the walls had high moisture content and mold issues.
My question is do we need to remove the asphalt from the fiberboard on the inside of the sheathing to allow drying to the outside? Ideally, we'll replace the BIBS with another BIBS but use the air and vapor permeable netting instead of the plastic (I guess they used poly back in the early 1990s).
It doesn't matter which way said product is facing. The biggest issue is where is the water coming from & stopping it / diverting it after drying out the cavities
In my opinion, this is not installed correctly as it will prevent natural drying towards the exterior wall (to avoid dampness and mold issues). Besides, unless I'm mistaken, this interior cladding wouldn't pass the Fire regulations.