Rule #1: Control Humidity

Mold cannot grow below 50% indoor relative humidity. This single metric matters more than any other prevention step.

How to keep humidity below 50%:

• Buy a hygrometer. $15 at any hardware store. Keep one in every main living area.
• Run the AC consistently. Don’t turn it off when you leave for the day. Set it to 76-78 while away, not off.
• Consider a whole-house dehumidifier if AC alone isn’t enough. Especially useful in older homes.
• Address oversized AC issues. An AC that cools too fast doesn’t dehumidify. Have a pro check.
• Use bathroom fans during and 20 minutes after showers.
• Use kitchen exhaust when cooking.

Rule #2: Fix Leaks Immediately

Every leak has a 24-48 hour window before mold starts. In Florida’s humidity, ignore the leak and you’re dealing with mold, guaranteed.

What to check monthly

• Under all sinks (kitchen, bathrooms, laundry).
• Around toilets (base and supply line).
• Behind the washing machine and dishwasher.
• Around the water heater.
• Ceilings under bathrooms.
• Attic (any staining on rafters or insulation).

Rule #3: Maintain Your HVAC

Monthly

• Change your AC filter (or every 90 days for high-quality filters).
• Check that condensate drain is flowing (pour a cup of water into the pan if accessible).

Annually

• Professional HVAC tune-up before summer.
• Coil cleaning if the tech recommends.
• Condensate line flush.
• Duct inspection for leaks or contamination.

Rule #4: Ventilate Properly

• Bathroom exhaust fans should vent to the outside, not into the attic. Common Florida code violation. Check yours.
• Attic ventilation requires proper soffit and ridge vents. Blocked soffits create humid attics.
• Kitchen range hoods should vent to outside.
• Dryer vents should be short, direct, and cleaned annually.

Rule #5: Watch the High-Risk Zones

Bathrooms

Run the fan every shower. Wipe down surfaces. Seal grout every 1-2 years. Watch for peeling caulk around tubs.

Attics

Check twice a year (spring and fall). Look for staining, wet insulation, and any signs of roof leaks.

Crawl Spaces

Annual inspection. Look for standing water, wet vapor barrier, or visible mold. Consider encapsulation if repeat issues.

Around AC Air Handler

Check monthly for pooling water. Any water pooling near the air handler indicates condensate drain issues.

The Post-Storm Protocol

After any tropical storm, hurricane, or heavy rain event:

1. Inspect the roof and attic for leaks.
2. Check for wind-driven rain intrusion around windows and doors.
3. Inspect ceilings for new water stains.
4. Dry any wet materials within 24-48 hours.
5. Call a professional if you find significant water intrusion.