Prevent Mold Growth in Your Garage

How to Prevent Moisture and Mold Growth in Your Garage

If your garage is constantly damp or moldy, you’re not alone. Garages, especially those built into hillsides or partially underground, are prone to moisture issues. These conditions create a perfect environment for mold, which can be persistent and harmful. Below, we’ll discuss effective steps to keep moisture and mold at bay for a cleaner, healthier garage.

Waterproofing Subterranean Walls

For garages built against or partially surrounded by soil, moisture from the earth can easily seep through the walls. This is especially common in basement garages or structures partially embedded in a hillside. Water naturally follows the path of least resistance, making underground walls vulnerable to leaks.

Solution: Waterproof exterior walls to keep soil moisture out. Professional exterior waterproofing involves applying liquid and solid waterproof membranes on the outside of the walls, blocking water from even reaching the wall itself.
Note: Avoid filling wall cracks from the inside. This can trap water inside the wall, causing structural damage over time as the water freezes and expands.

Install a French Drain

If your garage is located at the bottom of a hill or slope, rainwater runoff may flow directly toward it. This runoff can cause flooding, which, in turn, leads to chronic moisture problems and mold. Installing a French drain can help direct this water away from the garage.

What Is a French Drain? A French drain is a trench filled with gravel or rock and includes a pipe that redirects water away from vulnerable areas. When installed in front of the garage, it acts as a barrier, stopping rainwater from flowing toward the entrance.
Benefits: French drains are durable, low-maintenance, and allow for vehicle access.

Preventing Mold Growth

Once you’ve taken steps to reduce water entry, the next priority is to address any existing mold and prevent it from returning. Here’s a breakdown of effective mold removal and prevention solutions:

Bleach: A cost-effective, strong cleaner for removing existing mold. However, bleach does not prevent mold from regrowing, so it’s best used as an initial cleaning agent.
Concrobium: A non-toxic, EPA-approved mold remover that kills mold and creates a barrier to prevent future growth. Concrobium is safe for most surfaces, including plastic and painted areas, and doesn’t leave a toxic residue like bleach.
Grapefruit Seed Extract: A natural, safe option for preventing mold regrowth. Mix with water, spray on affected areas, let it sit for a few minutes, and then wipe clean. Grapefruit seed extract prevents mold from returning and doesn’t have strong odors or toxic effects.

Keep the Garage Dry with a Dehumidifier

Even after waterproofing and mold treatment, garages can still have high humidity levels, especially in rainy or humid seasons. If the air in your garage remains humid, mold can still grow on items that are harder to treat, like cardboard boxes or wooden surfaces.

Solution: Use a dehumidifier to reduce moisture levels in the air. A dehumidifier pulls excess water from the air, preventing mold growth on surfaces that can’t be directly treated. For optimal results, set up the dehumidifier to maintain a relative humidity level below 60%, as mold generally thrives above this threshold.

Final Tips for Long-Term Maintenance

To keep your garage free of moisture and mold over time, consider these final maintenance steps:

Regularly inspect walls and floors for any new cracks or damp spots, especially during rainy seasons.
Keep the French drain clean and clear of debris to ensure it effectively redirects water.
Run the dehumidifier as needed, especially during high-humidity months, to keep moisture under control.

By following these steps, you can create a dry, mold-free garage environment that’s safe and resilient. Proper moisture control and mold prevention will not only protect your garage but also improve the air quality and overall health of your home.