How to spot hidden subfloor damage covered by new OSB
Sellers sometimes cover up subfloor staining, mold, or urine by laying new OSB right over it. Buyers are left guessing whether the underlying issue was actually fixed or if they are inheriting a costly hidden problem before closing.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1guessing it needs the subfloor ripped out and replaced
- 2putting down new OSB and covering with LVP
- 3watering the foundation during dry periods to keep clay soil from shrinking
- 4calling a structural engineer to assess the damage and remediation options
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“curious if we are looking at mold, pet staining, or _____. We do know they placed new OSB over it. This is out of my wheelhouse and if anyone has any idea we would appreciate it.”source ↗
“My biggest curiosity is if I should be concerned if they didnt actually remove the issue if it's urine or mold.”source ↗
Where this came up
People with this problem also raised
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- 2How serious is a sewer scope belly under the street?