Same symptom.
Different pathway.
Use side-by-side timing, location, pattern and verification checks before treating a symptom as a confirmed cause.
Roof leak vs plumbing leak
Use rain timing, fixture timing and what lies above the stain to separate two common ceiling-water pathways.
Compare evidence →Diagnostic comparisonRoof leak vs condensation
Compare liquid water entry with vapor condensing on a cold surface.
Compare evidence →Diagnostic comparisonSurface growth vs soot deposition
Texture, wetting and distribution help separate dark biological spotting from airborne particles.
Compare evidence →Diagnostic comparisonEfflorescence vs surface growth
Dry crystals and soft organic growth require very different interpretations.
Compare evidence →Diagnostic comparisonWindow condensation vs failed glazing seal
The pane surface and whether moisture can be wiped away provide the decisive clue.
Compare evidence →Diagnostic comparisonThermal bridge vs air leak
A cold surface and a moving draft can feel similar but require different checks.
Compare evidence →Diagnostic comparisonDrain blockage vs vent obstruction
Flow restriction and pressure imbalance overlap but affect fixtures differently.
Compare evidence →Diagnostic comparisonPipe expansion vs water hammer
Slow temperature movement creates ticking; rapid pressure change creates impacts.
Compare evidence →Diagnostic comparisonFinish crack vs settlement
Geometry, material and change over time separate cosmetic finish movement from structural movement.
Compare evidence →Diagnostic comparisonWindow flashing failure vs sealant failure
Both can wet openings, but entry location and wall drainage behavior differ.
Compare evidence →Diagnostic comparisonGround moisture rise vs foundation crack entry
A broad low band differs from a defined crack pathway.
Compare evidence →Diagnostic comparisonHigh humidity vs hidden leak
Widespread surface symptoms differ from one localized active source.
Compare evidence →