Diagnostic Guide
Why Is There Condensation on the Inside of My Windows?
Indoor window condensation forms when humid room air meets cold glass. Learn how surface location, timing, and affected windows narrow the cause.
MoistureDiscoloration
Home system
Windows & Doors problem guides
Drafts, condensation, sticking, gaps, locks, and water intrusion. Start with a symptom or use the Problem Finder when you are not sure which guide fits.
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Published guides
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Diagnostic Guide
Why Is Mold Growing Around My Windows?
Mold-like growth around a window means the area stays damp. Use moisture timing, location, and damage patterns to find the source before cleaning.
MoistureDiscoloration
Diagnostic Guide
Why Are My Walls Sweating?
Moisture on a wall may be surface condensation or water arriving from elsewhere. Use location, timing, weather, and scope to narrow the source safely.
Moisture
Diagnostic Guide
Why Is There Condensation Between My Window Panes?
Fog or moisture trapped between window panes points to a different problem than condensation on accessible glass. Learn how to locate the moisture and compare glass, sash, and window options.
MoistureDiscoloration