Frost on corner walls with high cathedral ceilings
Only on the 2 walls which face east and north in zone 6 have frost on their corners and on the north side, have frost and moisture leading to the ceiling at the seam of the drywall. The drywall has moisture and will freeze when it gets below 20 degrees outside. The wall does not have anything obstructing it. A heater vent is 6 feet away near a window that is 2 feet away. The outside has vinyl siding. The house was built in the 80s and the attic has r50 to 60 in insulation value.
Only the corners with the cathedral ceiling in the house have this problem. Roof is a hip truss roof.. The other corners are 8 ft.
Soffits do have the vents that go up over the insulation. The house can be 20% humidity to 40% and still have a problem.
Hip truss roof
Cathedral ceiling
Zone 6
Unobstructed corners
Low humidity in the house
Frost and moisture on corners
Any remedies?
Replies
How much overhang does the roof have past the walls?
How tall are the walls where the problem is observed?
What kind of insulation provides the R50-60? How is this provided where the cathedral ceiling is?
as you likely suspect, the problem is lack of insulation in the area where frost and moisture collect. Have you used an IR temperature gun or thermal imager to map the temperature of the walls and ceiling in the area? You likely need to use a ladder or scaffolding to get closer to the area.
Remedy includes a couple options:
you can remove some insulation in the attic space and verify/replace insulation extends over the wall.
you can remove overhang soffit and access the top of the wall from there.
If the problem is wall cavity insulation which does not extend to the top of the wall, you can look into blown-in insulation to fill the gap. (via holes in the wall which are then patched) if it turns out the issue is missing wall insulation, and the soffit space extends over the missing part, you may also be able to remove soffit material for access and apply insulation inside the soffit, on the outside of the wall.
Thank you for your input and ideas.
Roof overhangs 16". Soffit is 6.5 ft away from the corner. No can lights in that area. Not sure whats in the wall, im guessing the typical r13 fiberglass. Attic had the fiberglass blown insulation added according to the papers on the house. I think the wind may have blow some of the insulation around or they didn't get the corners well. I'll have to investigate more.
Can lights in ceiling?