Before you start
Close it up overnight
Shut basement doors and windows the night before so odor concentrates and differences between rooms are easier to notice.
Bring tools
A bright flashlight, a hygrometer, a notepad, a screwdriver for outlet covers and a pair of gloves.
Go in fresh
Go downstairs first thing, before your nose adjusts. Step outside for fresh air between rooms if needed.
Mechanical and laundry area
Finished rooms, storage and crawl space
| Area | What to check | Notes column |
|---|---|---|
| Family room | Carpet edges along exterior walls; behind furniture on the foundation side | Record smell strength and location |
| Bedroom or office | Closet floor and corners; under the egress window | Record any staining |
| Bathroom | Exhaust fan works; base of toilet and shower; caulk lines | Record if fan is missing |
| Storage room | Cardboard on the floor; boxes against walls; soft box bottoms | Record which items smell |
| Ceilings | Stained tiles or drywall below upstairs plumbing | Record location |
| Crawl space hatch | Smell when opened; ground cover; standing water; insulation | Record humidity inside the hatch |
| Stairwell | Gap under the basement door; carpet on stairs | Record if odor rises upstairs |
Common questions
What if every room smells about the same?
An even smell across the whole lower level usually points to general humidity or to air arriving from one shared source, such as a crawl space or the furnace return. Start a humidity log and check the ductwork and crawl space before opening any walls.
Should I do this walkthrough in winter?
You can, but results are clearer from late spring through summer, when moisture is highest and odor is strongest. A winter walkthrough is still useful for drains, plumbing and storage, which do not depend much on the season.
My nose stops noticing the smell after a few minutes. What helps?
That is normal adaptation. Go outside for a couple of minutes between rooms, bring a second person who has not been downstairs that day, and write each impression down immediately rather than comparing from memory at the end.
General information for Lakewood, not a quote or professional advice. In an emergency, call 911.