Houston Heat: Leaky AC Condensation & Toxic Mold

By Franklin Everett Shaw

August 13, 2025

The air in Houston hangs heavy, thick with humidity. It’s a beautiful city, but that same humidity, combined with our aging AC systems, creates a perfect breeding ground for something far less appealing: toxic mold. We’re not talking about a little mildew in your shower; we’re talking about the kind of mold that can make you sick, damage your home, and drain your bank account. This isn’t just a cosmetic issue; it’s a serious health and safety concern that every Houston homeowner needs to understand.

Houston’s climate is practically an incubator for mold. The combination of high humidity and frequent heavy rains, especially during hurricane season, means that water intrusion is a constant threat. And where there’s water, there’s mold.

One of the most common culprits behind indoor mold growth in Houston homes is leaky AC condensation. Think about it: your AC is constantly pulling moisture out of the air. That moisture has to go somewhere, and if your drainage system isn’t working correctly, it can lead to standing water, damp drywall, and, you guessed it, mold.

So, how do you know if you have a problem? And more importantly, what can you do about it?

First, let’s talk about identifying mold. Visual inspection is the first step. Look for:

Visible mold growth: This can appear as fuzzy or slimy patches in various colors (black, green, white, brown). Pay close attention to areas around AC vents, under sinks, in bathrooms, and along exterior walls.
Musty odors: A persistent musty smell, even if you can’t see any mold, is a strong indicator of hidden mold growth.
Water stains: Look for water stains on walls, ceilings, or floors. These stains often indicate a past or present leak that could be fueling mold growth.

But visual inspection alone isn’t enough. Sometimes, mold can be hidden behind walls, under flooring, or in other inaccessible areas. That’s where mold testing comes in.

There are two main types of mold testing: DIY kits and professional testing. DIY kits are readily available at most hardware stores, including Lowe’s and Home Depot in the Houston area. They typically involve taking a surface sample or an air sample and sending it to a lab for analysis.

While DIY kits can be a good starting point, they have limitations. They often only identify the type of mold present, not the amount. This is crucial because even common molds can become problematic at high concentrations. Furthermore, DIY kits can be prone to false positives or negatives if not used correctly.

For a more accurate and comprehensive assessment, it’s best to hire a professional mold inspector. A qualified inspector will use specialized equipment, such as moisture meters and thermal imaging cameras, to identify hidden sources of moisture and mold growth. They will also take multiple samples, including air samples and surface samples, to determine the type and concentration of mold present.

In Houston, look for mold inspectors certified by organizations like the IICRC (Institute of Inspection, Cleaning and Restoration Certification) or the ACAC (American Council for Accredited Certification). These certifications ensure that the inspector has the necessary training and experience to conduct a thorough and accurate mold assessment.

Now, let’s say you’ve confirmed that you have mold. What’s next?

The first step is to address the source of the moisture. If the mold is caused by a leaky AC condensation line, you’ll need to repair or replace the line. This might involve:

Cleaning the drain line: Over time, the drain line can become clogged with algae, dirt, and debris. You can try flushing the line with a mixture of bleach and water or using a wet/dry vacuum to remove the blockage.
Replacing the drain line: If the drain line is damaged or corroded, it’s best to replace it entirely. This is a relatively inexpensive and straightforward repair that most homeowners can handle themselves.
Improving insulation: Condensation can also occur if the AC unit or ductwork is not properly insulated. Adding insulation can help prevent condensation and reduce the risk of mold growth.

Once you’ve addressed the moisture source, you can begin the mold remediation process. The extent of the remediation will depend on the size and severity of the mold problem.

For small areas of mold growth (less than 10 square feet), you may be able to handle the remediation yourself. However, it’s crucial to take proper precautions to protect yourself from exposure to mold spores. This includes:

Wearing personal protective equipment (PPE): This includes a respirator, gloves, and eye protection.
Isolating the work area: Seal off the affected area with plastic sheeting to prevent mold spores from spreading to other parts of the house.
Cleaning the affected surfaces: Use a mold-killing solution, such as a bleach and water mixture or a commercially available mold cleaner, to clean the affected surfaces. Be sure to follow the manufacturer’s instructions carefully.
Disposing of contaminated materials: Dispose of any contaminated materials, such as drywall or carpet, in sealed plastic bags.

For larger areas of mold growth (more than 10 square feet), it’s best to hire a professional mold remediation company. These companies have the training, experience, and equipment to safely and effectively remove mold from your home.

In Houston, look for mold remediation companies that are licensed by the Texas Department of State Health Services. These companies are required to follow specific protocols and procedures to ensure that the mold remediation is done safely and effectively.

Here are a few reputable mold remediation companies serving the Houston metro area:

Mold Remediation Houston: (This is a placeholder - research and insert a real company name and contact information). They offer comprehensive mold inspection, testing, and remediation services.
Houston Mold Experts: (Another placeholder - research and insert a real company name and contact information). They specialize in mold removal and prevention for residential and commercial properties.
[Insert a third company name and contact information here]

When choosing a mold remediation company, be sure to:

Get multiple quotes: Compare prices and services from several different companies.
Check references: Ask for references from past clients and contact them to see if they were satisfied with the company’s work.
Verify licensing and insurance: Make sure the company is licensed by the Texas Department of State Health Services and has adequate insurance coverage.

After a hurricane or severe rain event, the risk of mold growth in Houston homes increases significantly. Floodwater can quickly saturate building materials, creating a perfect environment for mold to thrive.

If your home has been flooded, it’s crucial to take immediate action to prevent mold growth. This includes:

Removing standing water: Use pumps, wet/dry vacuums, and fans to remove standing water as quickly as possible.
Drying out the affected areas: Open windows and doors to allow for ventilation. Use fans and dehumidifiers to speed up the drying process.
Removing damaged materials: Remove any damaged materials, such as drywall, carpet, or furniture, that cannot be thoroughly dried.
Cleaning and disinfecting: Clean and disinfect all affected surfaces with a mold-killing solution.

Even if your home wasn’t directly flooded, it’s still important to inspect for signs of water damage and mold growth after a hurricane or heavy rain event. Pay close attention to areas around windows, doors, and roofs, as these are common entry points for water.

Finally, let’s talk about the health risks associated with mold exposure. Mold can produce allergens, irritants, and, in some cases, toxins (mycotoxins) that can cause a variety of health problems.

Symptoms of mold exposure can include:

Allergic reactions: Sneezing, runny nose, itchy eyes, skin rash.
Respiratory problems: Coughing, wheezing, shortness of breath.
Headaches: Frequent or persistent headaches.
Fatigue: Feeling tired or weak.
Skin irritation: Rashes, hives, or other skin problems.

People with allergies, asthma, or other respiratory conditions are particularly vulnerable to the health effects of mold exposure. Children, the elderly, and people with weakened immune systems are also at increased risk.

If you suspect that you are experiencing health problems due to mold exposure, it’s important to consult with a doctor. They can help you determine if your symptoms are related to mold exposure and recommend appropriate treatment.

Preventing mold growth is always better than dealing with a mold problem. Here are a few tips for preventing mold growth in your Houston home:

Control humidity levels: Use dehumidifiers to keep indoor humidity levels below 60%.
Ensure proper ventilation: Make sure your home is properly ventilated, especially in bathrooms and kitchens.
Fix leaks promptly: Repair any leaks in your roof, plumbing, or AC system as soon as possible.
Clean and dry wet areas immediately: If you spill water or experience a leak, clean and dry the area immediately.
Use mold-resistant building materials: When renovating or remodeling, use mold-resistant drywall and other building materials.
Regularly inspect your home for signs of water damage and mold growth.

Dealing with mold in Houston can be a daunting task, but by understanding the risks, taking preventative measures, and knowing when to call in the professionals, you can protect your home and your health. Don’t let the humidity win; take control and keep your Houston home mold-free.