The snow piles up on them, trees dump sap and leaves on them, mildew can grow on them, and we won’t even discuss what birds do to them.  Okay, we will…did you hear about the rich pigeon?  He just made a deposit on a BMW. Same thing for skylights, except that if you have to look up at “the deposit” during breakfast every morning, it isn’t all that funny.

You should clean your skylights once or twice a year to keep the grime from building up, and permanently damaging the surface, especially on Plexiglas skylights. The grime and dirt can cause minute scratches to Plexiglas skylights, which will leave them with a clouded appearance.  This can be expected for older skylights, as Plexiglas degrades over time, or even for new skylights in areas that have acidic rainfall.  One great, albeit unusual tip, for Plexiglas and regular glass, is to wax the skylight with an automotive paste wax after it has been cleaned thoroughly.  A couple coats of wax, will protect against environmental damage, and will make rainfall bead off…..so you can see those horrible grey clouds.

Try to clean the inside and exterior on the same day.  Start on the inside by moving any furniture from beneath the skylight opening and lay a plastic cloth on the ground to catch any spills. Skylights are rarely placed for cleaning convenience, so determine the safest way to access the opening. Is it over a tub? Above a staircase? On a vaulted ceiling?  The inside doesn’t get very dirty, unless the skylight is in a kitchen, above a shower or tub, or near a fireplace. Usually the worst problem is spider webs, followed by grease build-up, and plain old dust.

If the skylight is flat glass, use a squeegee on the end of a broom stick or extension pole.  See the Window section for specific instructions.  For ‘bubble’ style lights, use a regular glass cleaner. If the skylight can not be reached by hand, try spraying some window cleaner on a clean rag draped over a broom. Replace that rag with a fresh, dry rag, to wipe off any residue and prevent streaks.


  • Bring up a bucket with dish soap and a sponge to the roof.  Don’t fill it with water until you are on the roof.
  • Take up your garden hose, and hose down the skylight.
  • Fill your bucket with water, and wash the skylight with the sponge.
  • Rinse thoroughly. If there is sap, bird, or bug excrement, use a citrus based cleaner. Be certain to test any chemical on a corner of the skylight to be certain it does not damage Plexiglas skylight lenses.

Safety:  It is advisable to have someone spot you when climbing the ladder. Always use caution on a wet roof or ladder. Never take undue risks, if in doubt, call a professional!

Leave a Reply

Your email address will not be published. Required fields are marked *


Enjoy this website? Please spread the word :)

Follow by Email