Airbnb Hosts in Miami: Preventing Mold Between Guests

October 17, 2026 · 4 min read

A vacation rental lives a different life than an owner-occupied home. It sits empty for days, then fills with people taking long showers after the beach, then sits empty again. Guests set the thermostat however they like, leave sliding doors open to enjoy the breeze, and check out with damp towels in a pile. In Miami's climate that pattern is close to ideal for mold, and a musty smell at check-in is the kind of thing guests mention in a review. The good news is that prevention is mostly routine, not expense.

Why short-term rentals are more exposed

Nobody is watching. A slow leak under a sink or a clogged AC drain can run for a week before the next person walks in.
The AC gets misused. Guests turn it off when they leave for the day, or run it very cold with the balcony door open, which pulls humid air inside and creates condensation.
Moisture loads are high. More showers, wet swimsuits, coolers, and laundry than a typical household.
Turnovers are rushed. Cleaners have a short window and focus on what guests see, not on the back of a closet.

Set the unit up to defend itself

The aim is to keep indoor relative humidity roughly between 30 and 50 percent, and always under 60, whether or not anyone is there.

Install a smart thermostat with temperature limits, so the system cannot be switched off entirely or left at extremes. Keep it cooling between stays; do not shut it down to save power.
Place an inexpensive humidity monitor in the unit, ideally one that sends alerts to your phone.
Have the AC serviced on a regular schedule, change filters often, and keep the condensate drain line clear. A float switch that shuts the unit off when the drain backs up prevents a lot of ceiling and closet damage.
Make sure bathroom exhaust fans actually move air and vent outside. A fan on a timer or humidity sensor removes the need for guests to remember.
Add water leak sensors under sinks, behind the washer and near the water heater and air handler.
Choose furnishings that tolerate humidity: hard flooring instead of carpet, washable shower curtains, and furniture kept a couple of inches off exterior walls.

Between stays: your cleaning team and your guests

Turnover checklist

Add these to the standard clean. They take only a few minutes.

Remove every wet towel, bath mat and linen from the unit. Never leave damp laundry in a closed washer or hamper.
Squeegee or wipe down shower walls and glass, and leave the shower door or curtain open to dry.
Look under each sink and around the toilet base for drips or swollen cabinet floors.
Check the ceiling and walls near AC vents for spots or water stains.
Open closets and look at the back corners and the baseboards.
Confirm the thermostat is back on the between-guest setting and all windows and sliding doors are fully closed.
Leave the washing machine door and detergent drawer ajar. Wipe the door gasket on front-loaders.
Note any musty smell on arrival, before cleaning products mask it, and report it.

Simple house rules for guests

Guests generally cooperate when the request is short and explains why. Consider a line or two in the house manual:

Please keep sliding doors and windows closed while the air conditioning is running.
Please leave the air conditioning on when you go out; South Florida humidity builds quickly.
Use the bathroom fan during showers and hang towels on the bars or hooks.
Let us know right away about any leak or water on the floor.

Long gaps and the off-season

If the calendar is empty for weeks, especially in the summer rainy season, have someone walk the unit on a regular schedule. They should check the humidity reading, run water in every drain so traps do not dry out, flush toilets, and look at the AC drain pan. During hurricane season, plan for power outages, since a unit without AC for several days in August will get damp quickly.

What you can clean and what you should not

Surface mildew on tile grout, caulk or a shower curtain is ordinary housekeeping. A musty smell with no visible source, growth on drywall or ceilings, stains that return after cleaning, or anything connected to a leak is different. Painting over it or masking it with air freshener before the next check-in does not fix it and can leave guests in a unit with an active problem. If you want testing, an independent licensed mold assessor provides that; remediation companies in Florida do not assess the same property they remediate.

If you find a problem

Block the calendar, stop the moisture source, and get the affected materials properly removed before the next booking. To have the job scoped and priced, request an on-site remediation estimate at drymiami.com or call (954) 778-7999. The visit is $79, credited in full toward the job if you hire DryMiami.

Mold problem at home?

We come out, find the moisture source and give you a written remediation estimate. The visit is $79, credited in full toward your job if you hire us.

Request an Estimate (954) 778-7999