How to Remove Mold from Wood Window Frames: Safe and Effective Solutions

How to Remove Mold from Wood Window Frames: Safe and Effective Solutions

Updated: 04.24.2024

By Nina Tsoy

Mold growth on wood window frames and sills is a common problem, especially in homes with high humidity or moisture issues. Not only is mold unsightly, but it can cause health problems by releasing mold spores into the air and aggravating respiratory conditions like asthma and allergies. Nobody should have to deal with this!

Thankfully, removing mold from wood windows is a task most homeowners can tackle on their own with some basic supplies and techniques. Our experts at Apex Window Werks know firsthand how to help you deal with mold. We’ll walk through the steps to get rid of mold, prevent its future growth, and in which situations it’s better to apply for professional wood window repair services.

Understanding Mold

Understanding Mold

Before tackling mold removal, you should first understand what you’re dealing with. Mold is a fungus that thrives in damp environments. It reproduces by releasing spores that can travel through the air and land on surfaces. When these spores come into contact with moisture, they germinate and start to grow.

There are many different types of mold, but some of the most common ones found on wood window frames include:

  • Aspergillus: Yellow, green, or gray and grows on damp walls, ceilings, window frames, etc.
  • Cladosporium: Olive-green or brown and grows in warm, wet areas like bathrooms.
  • Stachybotrys chartarum: The infamous “black mold” that has a slimy texture.
  • Penicillium: Blue, green, or yellow mold that grows on water-damaged materials.

While some mold species are relatively harmless, others can cause respiratory problems, skin irritation, and allergic reactions. If you have a severe mold infestation or suspect the presence of black mold (Aspergillus niger), we recommend consulting with a professional mold remediation company.

Killing Mold from Window Wooden Surfaces Step-by-Step

Removing mold from your wood window frames is an important task that not only improves the appearance of your home but also protects your health and the structural integrity of your windows.

Follow these steps to safely and effectively eliminate mold using natural or commercial cleaning solutions:

Killing Mold from Window Wooden Surfaces Step-by-Step

1. Wear Protective Gear

Before starting any mold removal project, it’s essential to protect yourself.

Mold spores can cause irritation and allergic reactions, so always wear protective clothing:

  • Rubber gloves to avoid contact with your skin.
  • Safety goggles to shield your eyes.
  • A face mask or respirator to avoid inhaling spores.
  • Old clothing that covers your arms and legs.

2. Prepare the Work Area

Once you have your safety gear, it’s time to prepare the work area.

Here are the steps to follow:

  • Remove window coverings (curtains, blinds) and any objects near the window.
  • Open windows to improve ventilation. If possible, create a cross-draft to promote airflow.
  • Lay down drop cloths or plastic sheeting to protect the floor and surrounding surfaces from mold spores and cleaning solution.

3. Identify the Mold

Many different molds can grow indoors. The most common are:

  • Aspergillus
  • Cladosporium
  • Stachybotrys chartarum
  • Penicillium

Knowing what type of mold you’re dealing with can help determine the best removal method and whether you need professional help. If you suspect you have toxic black mold, you’ll need to consult with a mold remediation specialist.

4. Clean Surface Mold

4. Clean Surface Mold

For surface mold that hasn’t penetrated deep into the wood, you can usually clean it with some standard household products:

  • In a spray bottle, mix a solution of 1 part dish soap with 10 parts warm water.
  • Spray the affected area thoroughly to wet the mold. Let sit for 5-10 minutes.
  • Using a soft-bristled brush, scrub the mold to loosen it from the surface.
  • Wipe away the residue with a damp cloth or sponge. Rinse your clothes frequently in clean water.
  • Once all visible mold is gone, wipe the surface again with a clean, damp cloth.
  • To kill any remaining spores, spray with undiluted white vinegar or 3% hydrogen peroxide. Do not mix these!
  • Let the air dry completely. Place a fan or space heater nearby to speed up drying if needed.

This simple soap and water method is safe for all non-porous surfaces like glass and tile. However, porous materials like wood may need a stronger solution.

5. Kill Mold on Wood

If mold has started to penetrate wooden window frames and sills, you’ll need to use a product that can seep into the wood grain to kill the roots. Commercial mold removers contain fungicides but can give off strong fumes.

For a more natural solution, try a baking soda or borax treatment:


White vinegar is a natural disinfectant with mild acidic properties that can effectively kill mold spores.

Here’s how to use it:

  • Mix a solution of one part white vinegar with two parts water in a spray bottle.
  • Spray the affected area generously with the vinegar solution.
  • Let the solution sit for 30 minutes to an hour, allowing it to penetrate the mold and kill the spores.
  • Scrub the mold with a soft-bristled brush to loosen and remove it.
  • Wipe the area clean with a damp cloth and then dry it thoroughly with a clean, dry cloth.

Baking Soda

4. Clean Surface Mold

  • In a spray bottle, mix 1/4 cup baking soda with 1 quart of warm water. Shake to dissolve.
  • Spray the moldy wood thoroughly to saturate it. Let sit for 15 minutes to an hour.
  • Using a stiff-bristled brush, scrub the area to remove mold and stains.
  • Wipe with a damp cloth and spray again with the baking soda solution.
  • Allow to air dry completely. The baking soda will kill any remaining mold and deodorize.


Borax is another natural cleaning agent that can be effective against mold. Here’s how to use it:

  • In a bowl, mix 1 cup of borax powder with 1 gallon of hot water. Stir to dissolve.
  • Using a brush, apply the solution liberally to the moldy wood.
  • Scrub the surface to loosen the mold then wipe away residue with a cloth.
  • Reapply the borax solution and allow it to air dry fully. Borax will prevent the future growth of mold.

Commercial Mold Cleaning Products

If the mold infestation is severe or the vinegar or borax solutions don’t effectively remove the mold, you can use a commercial mold remover. When choosing a commercial product, look for one that is EPA-registered and safe for use on wood surfaces. Always follow the manufacturer’s instructions carefully.

Important Tips

  • Never mix bleach with ammonia, as this can create toxic fumes.
  • Avoid using excessive water, as this can further saturate the wood and promote mold growth.
  • Allow the wood to dry completely after cleaning to prevent mold from reoccurring.
  • Address the root cause of the mold problem. Mold thrives in damp environments. Look for sources of moisture, such as condensation, leaks, or poor ventilation, and take steps to address them.
  • For extensive mold damage that has rotted the wood, the affected areas will need to be replaced entirely. Consult a window professional to assess whether repairs or full replacement is needed.

Ready for Mold-Free Windows?

Discover the best methods to remove mold from wood window frames. Contact us today for expert advice and a mold-free environment!

Schedule an Estimate

or call us (847)-443-5145

Prevent Future Mold Growth

Mold thrives in moist environments, so the key to preventing regrowth is controlling excess moisture:

  • Maximize natural ventilation and fresh air by opening windows when weather conditions allow for it.
  • Run bathroom and kitchen exhaust fans during and after showering/cooking.
  • Use air conditioning to help control humidity and keep your home cool.
  • Ensure proper drainage around your windows to prevent water from pooling near the frames.
  • Use a dehumidifier in chronically damp rooms to keep indoor humidity under 60%.
  • Repair any window leaks promptly and replace cracked/missing caulking.
  • Avoid putting furniture or curtains right up against windows to allow airflow.
  • Wipe down condensation from window surfaces promptly to prevent moisture buildup.
  • Regularly inspect your window frames for signs of mold and excess water, especially after heavy rains or periods of high humidity.
  • Painting or staining your wood window frames can create a protective barrier that helps resist mold growth.
  • Sanding down heavily discolored or damaged wood before applying the cleaning solutions can help in the process.

Identifying the Source of the Moisture

Even if you successfully clean mold from your window frames, if you don’t address the reason for the moisture, the mold will likely return.

Here are some common culprits and how to address them:

Identifying the Source of the Moisture

  • Condensation: Condensation occurs when warm, moist air comes into contact with a colder surface, such as a window pane in winter. To reduce condensation, open your windows to increase ventilation, use a dehumidifier, or install exhaust fans in areas with high humidity.
  • Leaks: Check for leaks around the window frame, in the glass, or the roof or siding above the window. Have any leaks repaired immediately to prevent further water damage and mold growth?
  • Poor ventilation: Poor ventilation can lead to trapped moisture within the home, creating a perfect environment for mold. Improve circulation using fans, opening windows, and reducing clutter around air vents.

When to Call Professionals

When to Call Professionals

Knowing when to reach out to a professional is important. Consider calling the experts if:

  • The mold is extensive: A large mold infestation may require special containment and removal techniques to prevent spreading throughout your home.
  • Health concerns: Mold sensitivities and respiratory issues are best handled by specialists to ensure safe and complete remediation.
  • Suspected black mold: Toxic black mold (Stachybotrys chartarum) needs professional assessment and removal for your health and safety.
  • Structural damage: If mold has penetrated deep into the wood, causing rot or weakening the frame, replacement, and repair work by a window specialist may be necessary.

Beat Mold, Restore Your View with Apex!

The mold that penetrates wood window frames in your house isn’t just an eyesore — it can affect your health and damage your windows. It’s important to take action to improve how your windows look and create a healthier living space for yourself and your family. Mold-free windows make for a brighter, cleaner, and more comfortable home.

For smaller mold issues, natural cleaners often do the trick. If the mold is stubborn or covers a large area, consider a commercial mold remover. But remember, the most important step is fixing the moisture problem that caused the mold in the first place.

For severe mold problems, especially if you suspect black mold and extensive damage, the most effective method is to contact Apex Window Werks. With over 15 years of experience, we’re experts in mold removal and wood window repair! We can help you find the source of the moisture to ensure it doesn’t return. We serve Illinois, Minnesota, and Wisconsin!

Nina Tsoy

Nina Tsoy

With over 15 years of experience in the window repair, replacement, and manufacturing business, Nina is in charge for strategic solutions and exceptional operational performance at Apex Window Werks. This allows her to offer innovative techniques and solutions to address any window-related problem, all while adhering to industry standards and best practices.

Get a free estimate

Hire the Window Repair Company you can trust

Schedule an Estimate

or call us (847)-469-9485

similar posts

A Step-by-Step Guide on How to Replace a Window Pane in a Wooden Frame

A Step-by-Step Guide on How to Replace a Window Pane in a Wooden Frame

Unfortunately, broken window panes are a common occurrence, especially in older homes. They can be caused by a variety of factors, such as hail, wind, or even a stray baseball. While replacing a window pane may seem like a daunting task, it’s a relatively simple DIY project that can be completed in a few hours. […]

Updated: 04.18.2024

By Nina Tsoy

Wood Window Repair: A Comprehensive Guide to Restoring the Beauty and Function of Your Home

Wood Window Repair: A Comprehensive Guide to Restoring the Beauty and Function of Your Home

If your home features beautiful wood windows, you know how much character and charm they add. However, over time, these windows can deteriorate due to exposure to the elements, paint buildup, and general wear and tear. At Apex Window Werks, we understand the importance of preserving your home’s original character. Our team specializes in restoring […]

Updated: 04.16.2024

By Nina Tsoy

Window Thermal Insulation 101: 5 Benefits of Insulated Glass Units

Window Thermal Insulation 101: 5 Benefits of Insulated Glass Units

What Are Insulated Glass Units (IGUs)? A double-glazed window or insulated glass unit is a tight construction of two pieces of glass and an air chamber filled with inert gas. This air chamber plays a significant role in enduring the units with their benefits. The gas contains a desiccant material to absorb moisture, and the […]

Updated: 02.12.2024

By Nina Tsoy