At a glance
- Crawlspaces are damp by nature — soil moisture, plumbing, and outside air meet there.
- Mold grows on floor joists and the underside of the subfloor.
- Crawlspace air rises into the house — odors and spores can follow.
- Call (385) 250-2825 for an inspection.
Common causes
- Missing or torn vapor barrier over the soil
- Plumbing leaks — supply and drain lines run through crawlspaces
- Groundwater and spring runoff
- Dryer or bath fans vented into the crawlspace
- Condensation when warm, humid air meets cold surfaces
Signs upstairs
- Musty smell, especially in rooms over the crawlspace — musty smell guide
- Soft or bouncy floors
- Cupping hardwood
- Higher humidity indoors
Fixing it
- Find and fix the moisture source.
- Contain and remove or clean mold-affected wood; replace badly damaged insulation.
- Dry the framing to standard.
- Install or repair a vapor barrier over the soil.
- Recheck after the next wet season.
Related: crawlspace water damage · remediation vs removal.
Musty smell from under the floor?
Call (385) 250-2825 — answered live 24/7 by the Vault crew.
Mold remediation services · Crawlspace water damage · Mold remediation cost
More guides: Finished basement water damage · Mold or efflorescence?
In Provo? See mold remediation in Provo for inspection pricing ($99, $199 or $349) and how a job runs.