Symptom dossier

Frost inside the attic

Frost on cold roof surfaces often reveals warm humid indoor air reaching the attic and freezing before it can dry.

Urgency profileAct soon
Use timing, location and checks to separate competing explanations.

Frost is stored water

When temperature rises it can melt into insulation and framing. Investigate air leakage, ducts, ventilation and indoor moisture sources.

ObserveDistinguishControl sourceVerify
Living dossierPublished knowledge is connected and improved as new cases, images and outcomes are added. Updated 2026-07-20.