I have a cathedral ceiling on the North side of my house. This is the side of the house that gets hardest hit during wither months in the midwest. I have discoloration where ceiling and walls meet the entire length of the house..Mold?! I\\\\\\\’ve had insulation co come out. Result- adequate shoots & insulation. Good airflow. Bathrooms look to be vented to the outside, from what I can see. I\\\\\\\’m at a complete loss. Cannot get even an \\\\\\\”educated guess\\\\\\\” from insulation co, gutter co or even roofing co. Help! Where to start??
Hi Linn, I’m wondering how were they able to get into the cathedral ceiling’s rafter space and issue that statement :). It could be mold but not necessarily, I’m assuming that there’s a soffit / roof overhang along that discolored area. Sometimes, when they insulate walls and ceiling cavities, they leave a small gap between the insulation edge and wall plate (top and bottom 2×4’s or whatever your wall framing is), and where the ceiling meets the wall. Cold air blowing through the soffit vents during the winter finds its way into those empty cavities and cools down the drywall. Colder areas attract dust particles, candle soot, etc. creating so called “ghost marks”.
Depending on your exterior wall finish, i.e. if it’s an easy to remove wall siding, you could just take the top panel off, make a small cut in the wall sheeting underneath and check if there’s sufficient insulation in that top section of the wall cavity corresponding to the affected area.
Without opening the wall, when it’s cold, you could measure the temperature differential between the discolored areas and the those un-affected ones (or just touch it with your hand). If there’s a significant temp. difference, it is most likely what I described above.
Please let me know if you have any questions.