Causes of attic condensation in in the winter:
1) Air leaks: Warm, moist air from living spaces can escape into the attic through gaps around plumbing, wires, and light fixtures, and above the top
plates of walls.
2) Poor ventilation: Inadequate soffit or ridge vent airflow can trap moisture in the attic.
3) Roof leaks: Cracks or improperly installed flashing around vents and chimneys can allow rainwater to enter.
4) Stack effect: In winter, the "stack effect" can pull moist air from the home into the attic, leading to condensation on the cold underside of the roof
deck. Especially true in 20+ year older homes with newer HVAC/Humidifier units
5) Furnaces with humidifiers: Systems that add moisture to the air can contribute to attic condensation issues.
How to address attic condensation:
1) Fix the moisture source: This is the most critical step.
2) Seal air leaks: Air seal the attic floor to prevent warm, moist air from escaping the house. Use caulk or foam insulation around gaps, as traditional
insulation will not stop air movement. Attic access entries can often be the biggest issue.
3) Improve ventilation: Ensure soffit vents are NOT blocked by insulation or obstructions. Install baffle chutes at the soffits to maintain clear airflow
from the soffits to the ridge vent. Verify clear flow in EACH baffle chute.
4) Check the roof: Inspect and repair any roof leaks or flashing problems.
5) Vent appliances properly: Ensure bathroom/kitchen fans and other exhaust fans are vented to the outside, NOT into the attic.
