Miami Saunas: Is Cheap Wood Rotting Your Lungs?

By Franklin Everett Shaw

August 5, 2025

Forget the generic “relax and unwind” spa day. Let’s talk about the hidden danger lurking in Miami’s saunas: wood rot and mold, and the mycotoxins they release. This isn’t just about aesthetics; it’s about your lungs.

Miami’s relentless humidity is a breeding ground for trouble, especially in the enclosed, hot environment of a sauna. The combination of heat and moisture accelerates the decay of wood, leading to mold and the release of mycotoxins, which are toxic substances produced by certain molds. Inhaling these mycotoxins can lead to a range of health problems, from allergic reactions and respiratory issues to more serious long-term health effects.

The most common types of wood used in saunas are cedar and redwood, prized for their natural resistance to decay and their aromatic qualities. However, even these durable woods are vulnerable in Miami’s climate. Cedar, particularly Western Red Cedar, contains natural oils that act as preservatives. Redwood, similarly, has tannins that offer some protection. But these natural defenses are no match for constant exposure to high heat and humidity.

Consider a hypothetical scenario: A small, family-owned gym in Little Havana installs a new sauna to attract more clients. They opt for a cheaper, less treated cedar to save money. Within a year, they start noticing a musty smell and dark patches on the lower benches. Unbeknownst to them, mold is thriving, releasing mycotoxins into the air. Clients start complaining of headaches and respiratory irritation after using the sauna. This isn’t just a hypothetical; it’s a common occurrence.

So, how do you protect yourself? First, learn to identify the signs of wood rot and mold.

Here’s a step-by-step guide to inspecting your sauna:

Visual Inspection: Look for discoloration, dark spots, or a fuzzy growth on the wood. Pay close attention to areas near the floor, corners, and around the heater, as these are the most susceptible to moisture accumulation.
Smell Test: A musty or earthy odor is a telltale sign of mold. If you detect such a smell, investigate further.
Touch Test: Press firmly on the wood with your finger. If it feels soft, spongy, or crumbles easily, it’s likely rotting. Use a screwdriver or awl to probe deeper into the wood; if it penetrates easily, the wood is compromised.
Check Ventilation: Ensure the sauna has adequate ventilation. Stagnant air promotes moisture buildup and mold growth. Look for vents near the floor and ceiling.
Inspect the Heater: The area around the heater is prone to water damage from splashing. Check for rust, corrosion, and water stains.

Now, let’s talk about mitigation. If you find rot or mold, don’t panic. Here’s what you can do:

For Minor Mold Growth: Clean the affected area with a solution of bleach and water (1 part bleach to 10 parts water). Wear gloves and a mask to protect yourself from the mold and bleach fumes. Ensure the area is thoroughly dry after cleaning.
For Extensive Rot or Mold: Replace the affected wood. This is the most effective solution for severe damage. When replacing wood, consider using more durable, treated options.
Improve Ventilation: Install or upgrade ventilation systems to ensure proper airflow. Consider adding a dehumidifier to the sauna room to reduce moisture levels.
Use Non-Toxic Wood Preservatives: Apply non-toxic wood preservatives to protect the wood from moisture and mold. Look for products specifically designed for saunas and that are safe for use in high-temperature environments.
Regular Maintenance: Regularly inspect and clean your sauna to prevent rot and mold from developing. This includes wiping down the benches and walls after each use and ensuring the sauna is properly ventilated.

Choosing the right wood is also crucial. While cedar and redwood are good choices, consider these factors:

Kiln-Dried Wood: Kiln-dried wood has a lower moisture content, making it less susceptible to rot and mold.
Treated Wood: Pressure-treated wood is resistant to rot and insects, but ensure the treatment is non-toxic and safe for use in a sauna. Borate-treated wood is a good option.
Alternatives: Consider using alternative materials like ceramic tiles or stone for the flooring and lower walls, as these are impervious to moisture.

Miami-specific considerations:

Hurricane Season: Prepare your sauna for hurricane season by ensuring it is properly sealed and protected from flooding.
Salt Air: Salt air can accelerate corrosion and wood decay. Regularly clean the sauna to remove salt deposits.
Professional Inspection: Consider hiring a professional to inspect your sauna for rot and mold, especially if you are unsure about what to look for. A qualified inspector can identify hidden problems and recommend appropriate solutions.

One common mistake is neglecting the area beneath the benches. This is a prime location for moisture to accumulate and mold to grow. Regularly lift the benches and clean underneath them. Another mistake is using harsh chemicals to clean the sauna. These chemicals can damage the wood and release harmful fumes when heated. Stick to mild, non-toxic cleaners.

Let’s look at a real-world example: The Standard Spa in Miami Beach uses a combination of cedar and teak in their saunas. They have a rigorous maintenance schedule that includes daily cleaning, regular inspections, and the use of non-toxic wood preservatives. They also have a sophisticated ventilation system that ensures proper airflow and reduces moisture levels. This proactive approach helps them maintain a healthy and safe sauna environment for their guests.

Don’t underestimate the importance of ventilation. A simple exhaust fan can make a big difference in reducing moisture levels. Consider installing a timer on the fan to ensure it runs for a sufficient amount of time after each use.

Finally, remember that prevention is key. By taking proactive steps to protect your sauna from rot and mold, you can ensure a healthy and enjoyable experience for years to come. Don’t let the Miami humidity ruin your sauna experience. Take control and protect your lungs.