Window Mold Removal and Prevention

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What’s the first thing that comes to mind when you think of mold?

Did you imagine biting into a tangy piece of blue cheese or remember how quickly that penicillin took care of the infection you had?

Probably not.

More likely, nasty images of a black, slimy fungus came to mind that made you cringe.

If you’ve discovered mold on or around your window sills, it can be upsetting and cause for concern. Not only does mold look awful as it grows on your windows, but it can also cause some significant health issues for you and your family.

Before we tackle how to remove it and prevent it from growing again, let’s learn more about what it is and how it’s caused.

Mold Facts

mold removal lab test

What is Mold?

  • It’s a living organism.
  • It can grow as single-cell yeasts or multi-cellular filaments.
  • There are over 100,000 different species.
  • All types of mold require moisture to grow.
  • Mold spores can be disbursed by wind or water.
  • It is resistant to extreme temperature and pressure.
  • It can start to grow within 24 to 48 hours after water exposure.
  • Approximately 10 to 20 percent of the world’s population is allergic to mold.
  • Canada Health website describes some symptoms associated with mould exposure. Sensitivity to mold symptoms include congestion, eye irritation, asthma, wheezing or skin rashes. More severe symptoms can develop with continued exposure to toxic black mold and in extreme cases lead to permanent damage to the central nervous system or death.

While these facts can be disconcerting, there’s no need to panic.

First, follow these steps to remove the unsightly fungus, and then, take the necessary action to prevent it from growing again:

Mold Removal

Mold On Window

Of course, windows are supposed to keep moisture from getting into your house, but condensation and air infiltration can leave you with moldy window casings. It’s vital that you wear protective gear to keep prevent spores from touching your skin or getting into your lungs. You’ll need protective coveralls or long pants and a long-sleeved shirt, gloves, disposable hair and shoe covers, gloves, safety goggles and a mold safety face mask before you start. Make sure to keep children and pets away from the work area.

Tape plastic over doorways and air vents to prevent airborne spores from spreading to other parts of your home.

  1. Open the window. This will provide fresh air, easy access to all parts of the window, and help dry the affected areas.
  2. Use a spray bottle to mist the moldy window casings. This will reduce the spread of mold spores as you work.
  3. Mix together a few drops of dish detergent or baking soda with warm water. This will be used to clean the affected surfaces. Dip paper towels in the mixture and wipe down any area with visible mold. Take care to place the used paper towels in a plastic bag, seal tightly and discard. Stubborn spots can be cleaned with a plastic scraper.
  4. Prepare a mixture of 1/4 to 1/2 cup of bleach and one gallon of water. This will be used to disinfect the area and kill any remaining mold spores. Scrub the window casings and allow the bleach to cover the window casings for 15 minutes.
  5. Rinse with clean water and dry thoroughly. Use a window fan or hair dryer to shorten drying time.

There are other tested ready-to-use solutions for mold removal. One of them is Concrobium Mold Stain Eraser reviewed and recommended by Steve Maxwell. As Steve says this “…new product that’s not only surprisingly effective but also does more than the manufacturer claims.” You’ll want to look into it if you have mold on your windows and other surfaces.


microscopic mold spores
Macro of Mold

Mold spores are microscopic and impossible to see with the naked eye. To prevent them from spreading, make sure you disinfect anything you’d like to reuse by immersing them in the bleach and water mixture.

Keep clothing you wore separate from your regular laundry and wash in hot water as soon as possible. For an added layer of protection, use bleach in the wash cycle, if possible.

You can also use a negative air machine and a vacuum with a HEPA filter to remove up to 99.97 percent of lingering spores.

Prevent Re-Occurrence

While controlling moisture and mould growth on window surfaces requires some regular maintenance, it is usually only for three or four months during the winter that these steps are necessary. Once temperatures increase outdoors, condensation becomes less of a problem.

If all window sills in the house are cleaned at the beginning of spring, mould growth will typically not return until the next winter. If existing mould growth is not cleaned as summer approaches the mould growth will dry and will be harder to clean later.

There are several key issues that should be addressed to keep mold from reoccurring: Proper ventilation, eliminate moisture and keep the area clean.

Proper Ventilation

By increasing ventilation to the area, you’ll reduce moisture. This is especially important in bathrooms and kitchen areas where steam will be present. Open windows when possible, run exhaust fans and use a dehumidifier in summer months to remove moisture from the air.

Controlling humidity and keeping your home dry is the key to preventing and stopping mould growth.

Eliminate Moisture

It’s important to keep window sills and casings dry to keep mold from re-growing. Use a towel to remove condensation and pooling water from window sills and surrounding areas. Make sure gutters are cleaned out so rainwater and snow melt don’t spill over onto the windows. Seal leaks in and around the windows to prevent water from seeping in.

Keep the Area Clean

Mold spores are present in many forms including dust, so it’s important to keep the room clean where mold was removed. Wash the windows often using a vinegar and baking soda solution. Dust and vacuum the room regularly to remove lingering spores and prevent mold from re-growing.

Hidden Issues

Even after thoroughly cleaning visible mold from your windows, you may still notice a moldy smell or experience health concerns. If this is the case, you’ll want to investigate to see if there is a hidden mold problem.

It is also important to regularly inspect the condition of the caulking around the window to prevent condensation from entering wall cavities where moisture takes longer to dry.

Modern windows are also designed to drain and have drainage holes in the outer portion of the frame. The drain holes in the window tracks should also be checked regularly as part of good housekeeping and maintenance to ensure that debris has not clogged the holes.

There are various types of installation procedures for windows. There may be a drainage mechanism designed in the tracks or if the sills are flush it could cause condensate to run down the outside wall below the window. Regardless of the type of installation, good maintenance and proper care can avoid any water damage or possible mould growth that may occur.

Stay Ahead of Mold

Early detection is critical, so don’t ignore the issue. Check under wallpaper, behind drywall and ceiling tiles, in heating ducts, and underneath the bathroom and kitchen sinks. There may even be an issue with rotting wood windows that may have trapped mold in the crevices of the frame.

If you have checked everywhere and still notice the tell-tale odour, it may be time to bring in a professional to inspect your home. Contact the technicians at Ecoline Windows for a no-obligation evaluation. They will check the condition of your windows and frames to determine if you need replacement windows. You may only need a couple of replacements to stop mold in its tracks.

Although there is always a risk of mold growth in your home, maintaining a proactive approach through prevention methods will keep the problem under control, keep your windows looking their best, and help your family breathing easier.

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