The useful answer starts with timing and pathway
Pressure differences can pull odor from a crawlspace, drain, wall cavity or attached garage and release it elsewhere.
Best first comparison
Document when the symptom begins, what condition preceded it and where the first visible or measurable change occurs.
Before deciding on a repair
Compare at least one credible alternative cause and choose a check that can separate the two without creating new damage.
Observe→Compare triggers→Repair source→Verify outcome
Living field guideThis useful article is public now. Sources, cases and graph connections continue improving without blocking publication.
