The quickest method for cleaning skylights is to use a soft cloth or sponge to clean off the glass with mild soap and water and then dry the glass thoroughly using a squeegee, extending the cloth or sponge to the outside of the skylight from the ground if possible to avoid streaking. If the roof outside is high or steep, it is generally better to have a professional handle the job, as it is safer than attempting the work yourself.
Two things make people dread cleaning their skylights; the first is that the streaks show up only after the sun shines on it, and the second is that they have to climb up the ladder to clean it. The good news is that you can avoid both problems with the right cleaning method. This guide explains how to clean the inside, clean the outside without a ladder, identify when a cloudy skylight needs professional attention, and get them far cleaner.
Why Skylights Need a Different Cleaning Approach
Don’t grab a cleaner before finding out what your skylight is made of, as this will dictate what is safe for use. Glass skylights can generally withstand regular glass cleaners and more pressure than acrylic or polycarbonate. Polycarbonate and acrylic skylights are soft and scratch and haze easily, requiring a gentle hand and gentle products. One way to identify the material is to tap the top lightly with your fingers. Glass should feel cold and hard, while acrylic and polycarbonate should feel warmer and slightly flexible. Older domed or bubble skylights are typically made of plastic rather than glass.
Whatever type you use, avoid ammonia- or alcohol-based cleaners or anything that is abrasive, like scouring pads, razor blades, or scrapers. They can scratch the glass coatings and permanently fog plastic glazing, and both types of coatings have manufacturers who caution against them for that reason.
How to Clean Skylights From the Inside
This is the simplest aspect of the task, and most homeowners only need to do this a couple of times a year.
Step 1-Gather supplies and protect the area
You’ll need a gentle dish soap or glass cleaner (avoid ammonia-based types), a soft microfiber cloth or non-abrasive sponge, a bucket or jug of warm water, and a squeegee with an extendable handle if your skylight is not easily reachable. Place a towel or drop cloth on the floor below to prevent drips from damaging the floor, especially if you have hardwood or carpet.
Step 2 -Apply a mild cleaning solution
Mix a few drops of dish soap into warm water, dip your cloth or sponge, and wring out the excess so it’s damp rather than dripping. Wipe the glass in overlapping sections, working from one corner across to the other rather than scrubbing in circles, which tends to push grime around instead of lifting it.
Step 3-Rinse thoroughly
Wipe the same areas again with a plain cloth soaked in clean water to remove any soap residue. This is usually the biggest mistake made with window skylight cleaning and can leave a soap film that makes the glass appear hazy after the job is done.
Step 4-Dry completely with a squeegee to prevent streaks
Wipe the squeegee blade from top to bottom in one smooth movement, pushing the squeegee blade clean between each pass. Finish the edges and frame corners, where the squeegee can’t reach, with a dry microfiber cloth. Streaking is caused by leaving any moisture, even a thin film, behind as it dries out unevenly.
How to Clean Skylights From the Outside-Without Getting on the Roof
The pole extension allows you to clean most single-story residences and moderately pitched roofs without using a ladder.
Use a soft-bristle brush head mounted on a telescoping extension pole, such as a car-washing brush or brush for washing upstairs windows, attached to a hose, or dip the brush in a bucket of soapy water. Scrub the surface lightly in overlapping motions, rinse with the hose to remove the soap solution, then dry and reduce streaks with a squeegee attachment and pull across the glass. Usually, working from an angle off the ground, not directly overhead, will provide more reach and control.
Don’t “climb up” with a ladder, as this is precisely what a professional exterior cleaning is designed for, which we will discuss below, if your roof is too steep, your home is more than one story tall, or the skylight is too far out of reach for a pole to reach safely.
Getting a Genuinely Streak-Free Finish
Some minor changes will make all the difference between a streaky skylight and a clear one.
The number one reason for streaking is cleaning in direct sunlight, which can heat up and dry the cleaning solution before you can rinse it and squeeze it off. Make passes that overlap the previous ones to be sure that water is flowing in the same direction as you are wiping, and wipe over the frame edges with a dry lint-free cloth to catch any water that drips out from the squeegee. In a hard water region, use distilled or softened water to rinse-hard water can be a major source of the tiny white spots that appear when the glass is dry.
Fixing Cloudy or Hazy Skylights
Not all cloudy skylights require cleaning, and it’s important to determine the type of cloudy skylight before continuing to scrub.
If your skylight is a double-glazed window and the haze is not on the inside or outside surface but in the space between the two panes, it is virtually certain that the seal has failed and moisture has infiltrated-there is nothing you can do to clean it, and you should talk to someone about repairing or replacing it. If the fogging is on the inside surface, especially during the colder months, it is probably a problem with your ventilation and/or the humidity levels inside; a more powerful cleaner will not help, but reducing the humidity in the house and improving the airflow around the skylight will help. But if the skylight itself has a dull, scratched appearance on the surface, this is often caused by exposure to UV rays over time or from previous cleaning with an abrasive pad or ammonia-based product-it usually cannot be cleaned out.
The easy guideline is, if you’ve cleaned the skylight correctly and it’s still hazy shortly after cleaning, then the problem isn’t what you did with the cleaning; it’s time to call a pro to inspect the skylight.
Skylight Maintenance: Keeping Them Clean Longer
With a little extra maintenance between cleanings, your skylight maintenance routine will be kept simple. An ideal cleaning schedule is twice a year for inside and at least once a year for the outside; more frequently if in between trees or after a heavy storm season. Make sure gutters and roof flashing are kept free of debris, as when it rains, debris will be washed back down across the glass. In addition, if branches protrude over the roof, cut them back-less sap, pollen, falling branches touching the skylight equals less accumulation to clean between brushings-and that’s the main advice for keeping skylights clean with little effort.
DIY vs. Professional: When to Call for Help
The extension-pole method covers most single-story homes and moderately pitched roofs just fine on your own. Call in a professional when you’re dealing with a steep roof pitch, a multi-story home where the skylight is genuinely out of pole range, cloudiness that doesn’t clear up after a proper wash, or any sign of a failed seal or a leak around the flashing. And regardless of how confident you feel on a ladder, never walk on a skylight or put your weight directly on the frame to clean it-skylights aren’t built to be load-bearing, and standing on one is a safety risk under any circumstances.
Conclusion
Streak-free skylights really come down to two things: the right method and the right timing. Mild soap and water, a full rinse, and a proper squeegee dry, done on an overcast day and working from top to bottom, are usually enough to keep most skylights clear without ever touching a ladder. If your roof is hard to reach or a skylight stays cloudy no matter how carefully you clean it, that’s your cue to book a professional rather than keep working at it yourself.
FAQ's
Clean the interior about twice a year and the exterior at least once a year. Homes near trees, construction, or areas with heavy pollen or storms may need exterior cleaning more often, since debris and residue build up faster in those conditions.
It depends on the material. Glass generally tolerates standard glass cleaners, but ammonia-based products can damage acrylic and polycarbonate skylights over time, leaving them scratched or permanently hazy. When in doubt, stick to mild soap and water, which is safe on both.
Cost varies with roof height, pitch, and how many skylights you have, but many homeowners pay somewhere in the range of a standard exterior window-cleaning service, often bundled with gutter or roof cleaning. Get a quote based on your specific roof for an accurate number.
No. Skylights aren’t designed to bear a person’s weight, and standing directly on the glass or the frame risks a serious fall. Use an extension pole from the ground, or hire a professional with the right access equipment for anything out of reach.
