Warm humid indoor air escapes through ceiling penetrations and reaches cold attic materials.
Evidence supporting it
No strong confirming clue has been added yet.
Evidence weakening it
No direct contradiction is active yet.
Deterministic building intelligence
Follow the clues.
Follow the clues.
Reduce the uncertainty.
HouseSymptoms ranks likely causes from timing, location, weather and distinguishing evidence. The score is a transparent fit index—not a remote diagnosis.
21 diagnostic profiles31 failure fingerprints32 visual patterns
Active regional intelligenceGlobal baselineNo regional layer is active. Results use the global knowledge graph.
No terminology overrideSelect a regional pack to localize building language.
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Frost or ice inside the attic
Separate indoor air leakage, disconnected exhaust and wind-driven snow by distribution and weather timing.
See0evidence clues active
Transparent cause ranking
What currently fits—and why
Fit index compares this profile’s evidence. It is not a probability and does not prove a hidden condition.
Humid exhaust air is released into an attic, ceiling or wall cavity.
Evidence supporting it
No strong confirming clue has been added yet.
Evidence weakening it
No direct contradiction is active yet.
Fine snow enters an opening and later melts inside an attic or roof space.
Evidence supporting it
No strong confirming clue has been added yet.
Evidence weakening it
No direct contradiction is active yet.
Moist indoor air reaches a surface below its dew point and deposits liquid water.
Evidence supporting it
No strong confirming clue has been added yet.
Evidence weakening it
No direct contradiction is active yet.
Most useful missing evidenceDrips during thawFrozen condensate can melt and drip during warming.+
Other questions still available
What weather preceded it?
Cold snaps and wind-driven snow create different fingerprints.
