How to Clean Skylight Windows From Inside [2024 Guide]

Table Of Contents

It’s common to forget about your roof windows, given they’re usually not in working view. However, you’ll be surprised the day you decide to look up, fixing your gaze for a moment.

The first tell-tale sign that something is wrong is a reduction in the intensity of light entering your office buildings. You may also discover that dark patches appear on the glass pane. These signs mean your skylight needs maintenance — cleaning, to be precise.

In this post, we’ll guide you through how to clean skylight windows from the inside and when you may need to contact a professional glazier. Let’s start with the needed supplies before outlining a stepwise guide and other helpful tips.

What Do You Need to Clean Skylight Windows From the Inside?

Skylights let in light from above, but over time, they get covered in grime that blocks the sun. Luckily, you don’t need any special equipment to make them sparkle again. With a few simple supplies you likely have on hand, you can learn how to clean skylights from the inside.

clean skylight from inside

Here is what you will need to make your skylights shine once again:

  • A Stool or Ladder: Invest in a sturdy step stool or ladder to give you safe access to the skylights. For windows higher than 8–10 feet, a lightweight aluminium ladder may be your best option.  Ideally, you’d need someone to hold you steady too!
  • A Pole: An extendable window cleaning pole or long-handled mop can help you reach high windows safely. Look for one at your local hardware store that extends up to 15–20 feet.
  • Gentle Dish Soap: You’ll also want a mild dish soapy water or cleaning solution formulated for windows or skylights. Avoid harsh chemicals that can damage the glass. A soft microfiber cloth, lint-free rag, or squeegee will make quick work of wiping away dirt and debris.
  • Sponge/Scraper: For stuck-on messes, use a plastic scraper, scrubber, or abrasive sponge. Gently scrub in a circular motion, being careful not to scratch the glass. Rinse thoroughly with water when scrubbing to gradually soften the stains.
  • Bucket and Towel: Have a towel on hand to soak up drips and a bucket to collect dirty water. You may also want protective eyewear, gloves, and old clothes since cleaning skylights can get messy!

Now that you know what you will be needing, let’s walk you through the steps involved.

How to Clean Hard-to-Reach VELUX Windows in 4 Steps

Cleaning skylights can seem like an impossible task when you can barely reach them, let alone scrub and squeegee the glass. But with some helpful tools and tips, you can get your roof window sparkling clean without risking life and limb.

hard to reach VELUX windows

Here’s how to clean skylight windows from inside in 4 steps:

  1. Prepare your ladder.
  2. Get your supplies.
  3. Spray your cleaning solution.
  4. Wipe the glass clean.

Step 1: Prepare your ladder.

First, get your ladder or stool and place it in a comfortable position beneath the skylight. Your position should allow you to view the whole window from an angle; this will allow you to easily reach it with a pole or your hand when possible. Make sure the ladder is placed on level ground and avoid overreaching. Your safety is the priority here!

Step 2. Get your supplies.

Next, gather the necessary cleaning supplies: a spray bottle filled with a mixture of water and mild soap or a commercial glass cleaner, a microfiber cloth or soft rags, a non-abrasive sponge, and a plastic squeegee. Avoid using anything that could scratch the glass.

Step 3. Spray your cleaning solution.

Spray the skylight window cleaner solution onto the glass and use the sponge or cloth to wipe away any built-up dirt and debris. For tough stains, you may need to scrub a bit. Rinse well with water to remove all cleaning residue.

Step 4. Wipe the glass clean.

Use the squeegee to wipe the glass in one direction, pulling excess water and cleaner from the glass. Make multiple passes until most of the moisture has been removed. Any remaining droplets will air dry quickly without leaving spots.

Extra: Cleaning the outer part of a skylight.

For the outer part of the skylight, you’ll need to open the window latches (if your skylight can be opened) and rotate the sash 180 degrees (follow the manufacturer’s instructions and ensure they are capable of rotating). Once opened (which can be inward or outward), you can start cleaning the outer part if your skylight is inward-opening. For an outward opening skylight, stick your head out of the opening, ensuring your chest is midway, and repeat the cleaning process. 

Cleaning outer part of Skylight windows

For convenience, you’ll need a ladder that can stand comfortably while allowing you to stick your upper body outside of the skylight in case it opens outward. Continue reading for more skylight cleaning tips.

Top Tips for Cleaning Skylight Glass, Frames and Blinds

To avoid damages that may incur some costly repairs, keep the following tips in mind when cleaning skylights:

1. Use a mild skylight cleaner.

For the glass panes, avoid sharp or abrasive objects or chemicals that can damage the acrylic or scratch the surface. Regular dish soap without ammonia is a safe choice. Mix a few drops with warm water for an effective glass cleaner. For blinds, consider using a blend of baking soda, dish soap and water to gently lift away built-up dirt and grime.

2. Don’t forget the frames.

The frames and sills collect just as much dust and dirt as the glass. Use a vacuum with a brush attachment to clean narrow areas. For wider surfaces, a microfiber cloth, dampened with your mild glass cleaner, will do the trick. Pay extra attention to weep holes and drainage channels where debris can build up.

3. Protect your flooring.

Whether cleaning glass, frames or blinds, there’s a good chance dirty water will end up dripping down below. Protect flooring when removing skylight stains by laying down towels, a tarp or other waterproof covering. You can also place a bucket or container under the skylight to catch drips.

4. Consider professional blind cleaning

For skylights with blinds, the blinds themselves often require the most intensive cleaning. While you can spot-clean blinds yourself using the methods above, for deep cleaning, professional window cleaner services use special ultrasonic technology to thoroughly clean each slat. They can also re-tension and lubricate blinds to restore them to like-new condition.

Profesional blind cleaning

By following these useful tips, you’ll have your skylight sparkling clean in no time. While at it, pay attention to your window sealings and mechanisms. A broken seal or loose hinge might cause drafts, which can increase your business’s electricity bill; to avoid this, consider resealing your windows.

Extra Tip:

Maintenance periods such as this are the right time to take preventative measures. So, if you notice your windows’ integrity weakening or have been experiencing unusual temperature changes in your office buildings or an increase in energy bills, don’t hesitate to contact a professional glazier for evaluation.

Frequently Asked Questions

How do you clean the outside of a VELUX window from the inside?

To clean the outside of a VELUX window from the inside, you should rotate the window sash 180 degrees until it’s upside down. This can be done by pulling the top of the window towards you and flipping it over. Once in this position, the window will usually have a mechanism, such as a barrel bolt, that you slide into place to secure the sash; this holds the window steady while you clean the external pane safely from the inside of an office. Always ensure the sash is firmly secured before starting to clean.

Do window cleaners clean skylights?

Yes, window cleaners often include skylights in their cleaning services. They typically have the necessary equipment, like telescoping brushes and squeegees, to clean these high and often hard-to-reach windows. This allows them to perform the cleaning from a safe position without the need to climb onto the roof. Companies offering a professional cleaning service are experienced in handling the delicate task of cleaning skylights to ensure they remain low maintenance and provide clear views of the sky.

Do VELUX windows have self-cleaning glass?

Yes, many VELUX windows are equipped with self-cleaning glass, which is designed to help reduce the time and effort needed to keep the windows clear and streak-free. The self-cleaning glazing uses a special coating that reacts with sunlight to break down organic dirt. Then, when it rains, the loosened dirt is washed away, leaving the glass cleaner. This feature is especially useful for hard-to-reach skylights, ensuring they continue to allow maximum natural light into your office building without the hassle of frequent manual cleaning.

How often should skylights be cleaned?

To maintain a clear view and let the maximum amount of light in, it’s recommended to clean your skylights once or twice a year. Over time, they tend to collect quite a bit of grime, including dirt, dust, and the inevitable spiderwebs. Regular cleaning helps to ensure that your skylights remain in top condition, enhancing the brightness and overall look of the space they illuminate.

Can you pressure wash a skylight?

While it’s possible to use a pressure washer to clean skylights from the ground, it’s crucial to choose the right pressure setting. Too much pressure can damage the skylight’s flashing or other parts, while too little won’t effectively clean the surface. Therefore, finding the correct balance is key to safely and effectively pressure washing your skylight.


By following our stepwise guide on how to clean skylight windows from the inside, you’ll have your window units sparkling once again. No more looking at filthy glass or paying for expensive professional cleaners; just grab your supplies, put on some tunes, and get to work. Remember to look out for any sign of looseness or broken seals — they weaken the integrity of your windows and can cause increased energy bills and discomfort if left unattended. Contact the GLRE team if you notice such issues for a professional glazing inspection.

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