How to dry out a soggy crawlspace
Mitigating moisture and pulling it out of wood joists requires figuring out exactly where to start. It is hard to know whether to begin by clearing debris, running a dehumidifier, or installing an inside perimeter french drain to handle residual standing water. Until the right sequence is found, the space stays humid and can leave clothes smelling musty.
What the numbers show
Counted from the threads quoted below. How we count
- This comes up 18.1× more often in r/HomeMaintenance than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1installing a commercial dehumidifier with a pump and remote controlDid this help you?
- 2buying a unit rated for a significantly larger square footage than the actual spaceDid this help you?
- 3Installing an interior or exterior French drain routed to a sump pumpDid this help you?
- 4Encapsulating the crawl space with a plastic vapor barrierDid this help you?
- 5Running a dehumidifier in the spaceDid this help you?
- 6Cleaning gutters and extending downspouts further away from the foundationDid this help you?
- 7Relying on existing dehumidifiers and natural airflow over timeDid this help you?
- 8Monitoring the wood to see if it gets soft, spongy, or darkerDid this help you?
- 9Applying DIY anti-microbial or mold blocking sprays to the affected areaDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“There is a sump down there, but there is some residual standing water and it feels humid.”source ↗
“Our clothes smell a bit musty when we leave.”source ↗
“Where do I start? Clear debris, dehumidifier? Do I need a french drain around the inside perimeter?”source ↗
“I had to do this for a foundation on a slab but the processes similar for a crawl space or basement.”source ↗
Where this came up
People with this problem also raised
- 2Dryer vent blowing into crawl space
- 2Foundation vent won't fit because of rebar in the way
- 4Why is there condensation and damp spots on walls only on laundry days?
- 4Can you use fiberglass insulation in a basement after flooding?
- 2How to insulate a drafty floor over a basement or porch
- 3Can I insulate and finish basement walls if they get damp?