Miami Mold: Is Saltwater Intrusion Ruining Homes?

By Franklin Everett Shaw

August 8, 2025

The musty smell hits you the moment you open the door. It’s not just an unpleasant odor; it’s a warning sign, especially if you call Miami home. Saltwater intrusion, a growing threat in South Florida, is creating a perfect breeding ground for mold in our homes. This isn’t just a cosmetic issue; it’s a health hazard and a threat to your property value.

Miami-Dade County is particularly vulnerable. Rising sea levels are pushing saltwater further inland, seeping into the ground and wicking up into our buildings. This salty moisture creates an environment where mold thrives, even in places you wouldn’t expect.

Let’s dive into how to identify, combat, and prevent this problem, specifically tailored for Miami homeowners.

First, understand the enemy. Mold needs moisture, a food source (like drywall or wood), and a suitable temperature to grow. Saltwater intrusion provides the moisture, and our humid subtropical climate takes care of the temperature.

Moisture Testing: Your First Line of Defense

Don’t wait for visible mold. Invest in a moisture meter. These handheld devices can detect moisture levels in walls, floors, and ceilings.

How to use it: Press the probes into the surface you want to test. A reading above 16% in drywall or 20% in wood indicates a potential moisture problem.
Where to test: Focus on areas near the ground, around windows and doors, and in bathrooms and kitchens. Also, check areas that have previously experienced leaks.
Pro Tip: Keep a log of your readings. This will help you track changes over time and identify potential problem areas early.

If you find elevated moisture levels, investigate the source. Is it a leaky pipe, poor ventilation, or saltwater intrusion?

Ventilation: The Key to a Drier Home

Proper ventilation is crucial in Miami’s humid climate. It helps to remove excess moisture from the air, making it less hospitable for mold.

Bathroom and Kitchen Fans: Always use exhaust fans when showering or cooking. Ensure they vent to the outside, not into the attic.
Air Conditioning: Run your AC regularly, even when you’re not home. It helps to dehumidify the air.
Open Windows (Strategically): On dry days, open windows to allow fresh air to circulate. Avoid opening windows during periods of high humidity or rain.
Dehumidifiers: Consider using dehumidifiers in areas prone to moisture, such as basements or crawl spaces.
Challenge: Many older Miami homes lack adequate ventilation. Retrofitting ventilation systems can be expensive, but it’s a worthwhile investment in the long run.

Mold-Resistant Building Materials: Building for the Future

When renovating or building new, choose mold-resistant materials. This is especially important in areas prone to saltwater intrusion.

Mold-Resistant Drywall: This type of drywall is treated with a fungicide to inhibit mold growth. Look for products specifically designed for humid environments.
Cement Board: Use cement board instead of drywall in bathrooms and kitchens. It’s more resistant to moisture and mold.
Mold-Resistant Paint: Choose paints that contain mildewcides. These paints help to prevent mold growth on surfaces.
Pressure-Treated Lumber: Use pressure-treated lumber for any outdoor construction, such as decks or fences. This lumber is treated to resist rot and decay.
Example: Instead of standard carpet, opt for tile or vinyl flooring, which are less susceptible to mold growth.
Pitfall: Don’t assume that all “mold-resistant” products are created equal. Research the specific product and its performance in humid environments.

DIY Remediation: When to Tackle It Yourself

For small areas of mold (less than 10 square feet), you may be able to handle the remediation yourself.

Safety First: Wear gloves, a mask, and eye protection.
Cleaning Solution: Use a mixture of bleach and water (1 part bleach to 10 parts water) or a commercial mold cleaner.
Scrubbing: Scrub the affected area thoroughly with the cleaning solution.
Drying: Dry the area completely. Use a fan or dehumidifier to speed up the drying process.
Important: If the mold returns, it’s a sign that you haven’t addressed the underlying moisture problem.
Common Mistake: Simply painting over mold will not solve the problem. The mold will continue to grow underneath the paint.

When to Call a Professional: Don’t Hesitate

For larger areas of mold (more than 10 square feet) or if you suspect that the mold is widespread, it’s best to call a professional mold remediation company.

Why? Professionals have the equipment and expertise to safely and effectively remove mold. They can also identify and address the underlying moisture problem.
Finding a Qualified Professional: Look for companies that are licensed and insured. Check their references and read online reviews.
Beware of Scams: Be wary of companies that offer extremely low prices or guarantee to completely eliminate mold. Mold is a natural part of the environment, and it’s impossible to completely eliminate it.
Real-World Scenario: A homeowner in Key Biscayne noticed a musty smell in their living room. They initially tried to clean the area themselves, but the mold kept returning. They eventually called a professional, who discovered that saltwater was seeping into the foundation of the house. The professional was able to repair the foundation and remove the mold, preventing further damage.

Navigating Insurance Claims: A Miami-Dade County Guide

Dealing with mold caused by saltwater intrusion can be expensive. Your homeowner’s insurance may cover some of the costs, but it’s important to understand your policy.

Read Your Policy Carefully: Pay attention to the exclusions and limitations. Many policies exclude coverage for mold caused by flooding or rising water.
Document Everything: Take photos and videos of the damage. Keep records of all expenses related to the remediation.
File a Claim Promptly: Contact your insurance company as soon as possible after discovering the mold.
Be Prepared to Negotiate: Insurance companies may try to deny or reduce your claim. Be prepared to negotiate with them.
Consider Hiring a Public Adjuster: A public adjuster can help you navigate the claims process and negotiate with the insurance company on your behalf.
Specific Challenge: Proving that the mold was caused by saltwater intrusion, rather than a covered peril like a burst pipe, can be difficult. You may need to hire an expert to assess the damage and provide documentation.
Actionable Insight: Familiarize yourself with Florida Statute 627.706, which addresses mold damage claims. Understanding your rights under Florida law can be crucial in getting your claim approved.

Saltwater intrusion is a serious threat to Miami homes. By taking proactive steps to identify, combat, and prevent mold, you can protect your health, your property, and your peace of mind. Don’t wait until the musty smell becomes overwhelming. Start taking action today.