Dealing with Skylight Condensation in Winter

Every winter, homeowners across Cookeville, Crossville, and Sparta notice moisture collecting on their skylights. Sometimes it's a light fog, sometimes it's full dripping. Before you panic about a leak, understand this: most winter skylight moisture isn't a leak at all — it's condensation, and it's usually fixable without replacing anything.

Why it happens: Warm, moist air inside your home rises to the highest point — your skylight. When that warm air hits the cold glass surface, moisture condenses. It's the same reason your bathroom mirror fogs after a shower. Tennessee's winter humidity, even indoors, makes this especially common in Kingston, Oak Ridge, and Livingston.

How to reduce skylight condensation:

• Run bathroom and kitchen exhaust fans — Remove humidity at the source. This is the single most effective step.
• Use a dehumidifier — Keep indoor humidity below 40% during cold months.
• Open vented skylights briefly — Even in winter, a few minutes of ventilation breaks the moisture cycle.
• Check attic insulation — Poor insulation around the light shaft lets warm air surround the skylight, increasing condensation.
• Ensure proper flashing — If moisture appears between double-pane glass, the seal has failed and the unit needs replacement.

For homeowners in Monterey, Jamestown, and Pikeville — where winter temperatures can drop significantly on the Cumberland Plateau — condensation is more aggressive than in the valleys. Double-pane, argon-filled skylights with low-E coatings dramatically reduce condensation compared to single-pane or older models.

When condensation IS actually a leak: If water appears only during rain or snowmelt (not just cold mornings), you likely have a flashing problem, not a condensation problem. This is especially common on skylights in Spring City and Pikeville that were installed without proper step flashing or ice-and-water shield membrane.

Old Glory Roofing inspects, repairs, and replaces skylights across all of Middle Tennessee. If you're not sure whether your skylight is condensing or leaking, call us for a free inspection. We'll diagnose the issue and give you honest options.