A vacation rental gives a family things a hotel room rarely can: a full kitchen, a washer, a porch, and a door between the kids’ room and yours. For a long weekend in the mountains or a week at the beach, that space often costs less than two hotel rooms.
But there might be a major problem in these homes nobody inspects. The host might live three states away. A cleaning crew might turn the house over in two hours, and a beach cottage might sit closed and humid for most of the off-season.
My recent experience taught me way too much about these rentals…
You have probably walked into a rental, felt the air hit you, and caught something earthy under the fresh-linen spray. Then you unpacked anyway, because the drive was long and everyone was hungry.
So the question is, how do you know a rental is fine to sleep in before your clothes are in its drawers and the refund window has started to close?
I answer that with a five-minute routine, before a single suitcase opens.
Why I don’t unpack first
My nose gives me a few honest minutes in a new place. After that, smell receptors stop reporting a constant odor, and a damp room starts to feel normal.
I also don’t want our clothes hanging in a damp closet for a week and bringing that smell home with us.
There’s a deadline too. Airbnb gives guests 72 hours from discovering a problem to report it. Past versions of Vrbo’s guarantee, now called VrboCare, asked for a report within 12 hours of arrival.
Most of my places to stay over the years have been hotels and inns, where a damp room gets solved with one call to the front desk. With a rental, leaving usually means finding a whole new booking.
First, I stand at the door and breathe
Before I turn on a light or touch the thermostat, I close the front door and breathe normally for about thirty seconds.
What I’m sniffing for are the gases mold and bacteria release while they feed on damp wood, drywall and fabric. One of them, geosmin, is the same compound behind the smell of rain on dry soil. The nose picks it up in tiny amounts, so a colony hidden inside a wall can scent a whole room.
Earthy, like a cellar or wet cardboard, tells me something is growing nearby. Flat and stale usually means the house sat closed with the air conditioning off. A sewer-ish whiff by one drain is often just a dry drain trap.
I get a little wary when every outlet has a plug-in freshener or a candle is already burning when we arrive. Fragrance hides odor without touching its source. If I catch something earthy underneath it, I slow down for the rest of the walk-through.
Under the sinks and up at the bathroom ceiling
I open every cabinet under every sink with my phone flashlight on. I’m looking for dark spots on the cabinet floor, a swollen base, old water rings or a slow drip.
In the bathroom, I look straight up. Shower steam settles on the ceiling above the tub, and a weak exhaust fan leaves it wet for hours. I hold a square of toilet paper to the fan while it runs. If the paper doesn’t get pulled in, that bathroom stays damp.
Not everything in a shower worries me. Pink or orange film is usually a bacterium called Serratia marcescens that any bathroom cleaner removes. Grey film on grout is mildew. Black specks trapped inside silicone caulk look awful, but on their own they wouldn’t make me leave.
In the kitchen, I peek under the sink, around the dishwasher door seal, and inside the coffee maker’s water tank before anyone brews that first cup.
Then I turn on the air
I switch on the air conditioning or heat while I’m still walking around. Mold on a cooling coil or in the drip pan travels through every duct. If an earthy smell shows up a few minutes after the fan starts, the unit is the likely source.
Then I look at the bedroom vents. Dark speckling on the grille slats or a damp film on the cover means cold air is meeting humid room air.
Beach and lake houses often have ductless mini-splits mounted high on the wall. I shine my flashlight up through the open louvers to see whether the blower wheel inside is clean or speckled black.
If there’s a filter behind the return grille, I check that too. Dusty grey just means it’s due for a change, while a dark filter that smells earthy points to moisture inside the unit.
The beds and the closets
Bedrooms get the most attention, because that’s where we breathe for eight hours a night. I lift a corner of each mattress and look at the underside and the base below it. A sleeping body releases moisture into the mattress every night. On a solid platform or against a cold wall, that moisture can feed growth no housekeeper ever sees.
I also look behind headboards and dressers that sit against outside walls, where still air lets condensation form. Closets on outside walls get opened and sniffed. So do the spare pillows on the top shelf, since they soak up whatever the closet smells like.
Last come the windows: water pooled on the sill, black spots in the frame corners, or paint bubbling below the glass.
When I find a stain: a photo and a humidity number
If I find a stain I can’t identify, I photograph it and run it through a free mold scanner in my phone’s browser. It takes up to three shots of the same patch: a close-up from about a hand’s width away, one from arm’s length, and a wide one of the whole wall.
The report gives the odds that it’s mold, rules out lookalikes like soot and water stains, and points to the likely moisture source. It saves as a PDF, which I can attach straight to a message to the host. Daylight works better than the flash, which glares off tile.
I also pack a small digital hygrometer that fits in my toiletry bag. The EPA recommends indoor humidity between 30 and 50 percent. A rental sitting above 60 percent with the AC running is damp enough for mold, even when every wall looks clean.
When it smells musty and I can’t find anything
I start with the drains. Every drain holds a little water in its U-bend to block sewer gas, and in a guest bathroom nobody has used for weeks, that water dries up. Running each unused sink, tub and shower for about fifteen seconds refills it. The smell often fades within the hour.
If it doesn’t, I try a simple test that evening. I air out the room with the windows open, close it up for an hour, then open the door and breathe in. A musty smell that’s back right away means something in that room is still producing it, often behind furniture, under carpet or in the ductwork.
Doing this on the first evening still leaves me time to switch rooms, message the host or report it inside the platform’s window.
If the rental doesn’t pass
I take photos and short videos, including one wide shot that shows which room the problem is in. They go in one album with the scan PDF and a photo of the hygrometer.
Then I message the host through the booking app instead of texting, so the conversation is on record if it turns into a refund request. I keep it short and kind: what I found, where, and what I’d like fixed. Plenty of hosts sort out small problems the same day by cleaning a vent, swapping a mattress or sending someone over.
If the host goes quiet or the house just isn’t livable, I go to the platform:
- Airbnb can refund all or part of the stay, or rebook you somewhere comparable, if you report the issue within 72 hours of finding it.
- Vrbo handles problems through VrboCare, which focuses on access issues and significant misrepresentation. It has turned down cleanliness complaints before, so photos and a fast report matter even more there.
Consumer advocate Christopher Elliott wrote about a couple who left a Vrbo rental near Lake Tuckasegee, here in North Carolina, over a strong musty smell. Vrbo first told them the guarantee didn’t apply and reimbursed them only after he got involved.
If anyone in your group has asthma or allergies, I’d leave first and sort out the paperwork later. Damp buildings can make breathing problems worse.
What I look for before I book
I search a listing’s reviews for words like musty, damp, humid, mildew and AC. When a host replies with a specific fix, like a new air handler or a dehumidifier in the basement, I trust that they act on complaints. When they argue with the guest, I keep scrolling.
I also notice bathroom photos that crop out the ceiling, basement bedrooms with tiny high windows, and lake houses that sit empty all winter. I’m not shy about messaging a host before booking to ask when the HVAC was last serviced and whether a dehumidifier runs in summer. A careful host usually answers in detail.
And one last thing, if you think you are struggling with mold toxins, don’t hesitate to take a quick VCS test for mold.
