How to Clean Mold from Windows: Solution, Cause & Prevention

It is every homeowner’s nightmare to find mold buildup in their house while walking around.

The situation worsens if the mold is growing on your windows.

But worry not.

You can easily clean mold from your window by removing excess mold with a detergent solution, followed by a deep cleaning using undiluted distilled white vinegar or 3% hydrogen peroxide.

In this guide, I will show you how to clean mold from windows with seven easy steps!

At the end of the guide, I will also provide you with the most common reasons for mold buildup so you can watch out for them.

I will also add 15 tips for preventing mold growth, so keep reading!

How to Clean Mold from Windows?

In this section, I will take you through the step-by-step mold cleaning process from windows.

StepsEstimated Required Time
Step 1: Preparation5 minutes
Step 2: Place a Drop Sheet5 minutes
Step 3: Remove Excess Mold10 minutes
Step 4: Deep Clean the Window45-60 minutes
Step 5: Scrub the Window30 minutes
Step 6: Clean and Dry20 minutes
Step 7: Dispose of the Waste10 minutes

Step 1: Preparation

  • Before getting close to the mold, your first important move is to gear up in safety stuff.
  • You’ll need rubber gloves, goggles, and a good mask.
  • When you’re done in the mold zone, take off your gear.
  • No spores are allowed to wander.
  • Keep fans and AC low to avoid spreading those pesky mold bits around.

Required Tools

  • Rubber gloves
  • Safety goggles
  • Safety mask
  • Old clothes
  • Plastic bags

Step 2: Place a Drop Sheet

  • Put down a drop sheet or some towels below where you’ll clean.
  • This stops falling mold from spreading and messing up your place more.
  • It also prevents stains from bleach or cleaner dripping on your floor.
  • You can find drop sheets at hardware stores or supermarkets.
  • Tape down the drop sheet so it doesn’t slide or move around during cleaning.
  • Consider tossing a little diluted bleach in your washer if you plan to wash it and keep it.

Required Tools

  • Plastic sheet or drop cloth
  • Tape
  • Diluted bleach

Step 3: Remove Excess Mold

  • Before diving in, open the window to let in some fresh air.
  • Mix a few drops of detergent with warm water and put it in a spray bottle.
  • Spray the mixture on the affected area.
  • Now, take a dry, one-time-use microfiber cloth.
  • Wipe down the area to remove the excess mold.
  • Don’t worry about removing all the mold, just the easy-to-wipe bits.

Required Tools

  • Detergent
  • Warm water
  • Spray bottle
  • Dry, one-time-use microfiber cloth
Deep cleaning mold from windows

Step 4: Deep Clean the Window

  • Don’t use bleach for deep cleaning; it just removes surface mold, which grows back.
  • Get undiluted distilled white vinegar, the kind you might use for cooking.
  • Pour it into a spray bottle, and spray those moldy spots really well.
  • Wait for 60 minutes – give it time to do its thing.
  • Grab a warm, disposable cloth and wipe the area clean.
  • Give the spots one more spray and let them air dry.
  • That’ll make sure the mold’s really gone.
  • If you don’t have vinegar, you can use hydrogen peroxide.
  • It’s natural and strong.
  • Fill a spray bottle with 3% hydrogen peroxide.
  • Mix it with hot water and spray the mold for glass and similar surfaces.
  • Wait 15 minutes, then use your cloth to rinse and wipe.

Required Tools

  • Undiluted distilled white vinegar
  • Spray bottle
  • Warm, disposable cloth
  • Hydrogen peroxide

Step 5: Scrub the Window

  • Mix one teaspoon of baking soda with two cups of water in a spray bottle.
  • Give it a shake and spray it on the mold.
  • Grab a brush or scrub pad and start scrubbing.
  • After that, use a warm cloth to wipe the area clean.
  • Give it one more spray and let it air dry.
  • You can use bleach for scrubbing if you don’t have baking soda at hand.
  • Mix 1/4 to 1/2 cup of bleach in a gallon of water.
  • Dip a clean rag in this mix and scrub away on the window frame and glass.
  • Wait for 15 minutes to let the bleach disinfect and kill the mold.
  • This kind of heavy scrubbing may damage the window’s paint.
  • But don’t worry; you can always repaint and repair your windows.

Required Tools

  • Baking soda
  • Water
  • Spray bottle
  • Brush or scrub pad
  • Clean cloth
  • Bleach

Step 6: Clean and Dry

  • After using your cleaning stuff and scrubbing off the mold, it’s time to dry up that clean window.
  • Wash the window frame and glass with clean water.
  • Rinse them real good.
  • Dry everything really well.
  • Use a fan or a hair dryer to dry things faster if there’s no breeze.
  • Speedy cleaning and drying matter a lot.
  • We’re aiming for zero dampness here.
  • If it’s all dry, those sneaky spores won’t settle in.
  • Once the window dries, spray a little hydrogen peroxide.
  • That takes care of any last stubborn ones.
  • Just let the window air dry after that final spray.

Required Tools

  • Clean water
  • Fan or hair dryer
Scrubbing off the mold from windows

Step 7: Dispose of the Waste

  • If you’re using paper towels to clean up, toss them in your trash bags right away.
  • But if you’re going for reusable towels or rags, take them straight to your washing machine after you’re done.
  • Wash them with a bit of bleach or laundry detergent with bleach.
  • Your safety gear, the drop sheet, and towels can usually be used again.
  • Just give them a good cleaning, following the product’s instructions.
  • Mold usually goes out like regular waste.
  • Take it to a dumpster or a trash spot nearby.

Required Tools

  • Trash bags
  • Washing machine
  • Bleach or laundry detergent with bleach

What Causes Mold on Windows?

Mold growth on windows often happens because of excess moisture, which can come from leaks or condensation.

Bathrooms and kitchens, where moisture is common, are particularly susceptible to mold growth.

On aluminum windows, mold tends to accumulate where dust and moisture meet.

This creates an ideal environment for mold growth.

The situation is similar for wooden windows, where the joint between the wood and glass can trap moisture, promoting mold growth.

Common causes of moisture that contribute to mold growth on window frames include

  • Leaking pipes
  • Faulty heating or ventilation systems
  • Roof leaks
  • Steam from cooking or showers
  • Inadequate airflow

While window glass panes don’t cause mold, neglecting to dust them can lead to mold forming inside the window pane.

Moreover, trapped moisture between double-paned windows can create mold between glass panes.

How to Prevent Mold on Windows?

  • To keep mold at bay, you’ve got to keep an eye on moisture.
  • Regularly wipe away any dampness that finds its way onto your window frames.
  • A quick wipe with a dry cloth will do the job.
  • And when you can, crack open those windows after it rains.
  • This lets fresh air in and helps dry out those window wells.
  • Remember to clean your window wells every month or two to stop mold from getting cozy.
  • Bring out the dehumidifiers and air conditioners when the weather is hot and humid.
  • In the chilly winter months, turn to humidifiers.
  • They’re your secret weapon against excess condensation.
  • Check if your kitchen and bathroom exhaust fans are working properly.
  • If not, think about getting some installed. Good ventilation is your friend.
  • Every now and then, throw open your curtains and windows.
  • Let that crisp airflow through your home for about 5 to 15 minutes daily.
  • For those using air conditioners, keep them clean and free of dust.
  • Also, make sure the drain pipes are clear and working perfectly.
Keeping your window clean for mold prevention

Bottom Line

And there you have it, mold-free windows good as new!

It’s important to follow every step mentioned in this guide to achieve an outstanding result.

Remember to look out for the reasons for mold growth.

You should also follow the prevention tips given in this guide so your windows remain fresh for longer.

Happy DIYing!


What kills mold on windows?

Undiluted distilled white vinegar.

You can use it in a spray bottle, and it kills 80% of different mold species.

Is window mold harmful?

Typical window molds don’t pose a serious threat but can trigger several allergies.

However, black mold can produce toxic mycotoxins, leading to long-term damage to respiratory health and serious mold poisoning.

Is bleach or vinegar better for mold?

Bleach is more likely to remove the surface mold, as it doesn’t kill the mold buildup.

On the other hand, vinegar is more effective in killing and removing mold from any penetrable surface permanently.