If your skylights are covered in pollen, tree sap, moss, dried concrete, or even just the factory sticker residue, this is the post for you. Get that glass functional again before the outdoor temps are so high the roof melts the rubber on your shoes!
Step one: lightly wipe off anything that will come off easily with a dry towel. Emphasis on lightly. This is mostly for pine needles and the like. You want them off the glass so they don’t scratch it in the next steps.
Step two: with your scrubber—no, windex and paper towels will not do the job—go over the entire surface of the glass, again fairly lightly. You want to get a lot of water sitting on the pane, don’t try to scrub of all the tough spots yet.
Step three: razor blade! This is what gets all the gunk off that’s been building up for years. Grab a fresh razor. The small two inch ones work, but if you have a larger one with a handle like what I’m using, things will go much quicker. The key to razoring without turning your glass into a horrendous mass of scratches is to keep things wet, apply even pressure with the blade and never scrape in a back and forth motion. This is the scary step, but once you’re proficient with a blade you can have the privilege of saying you’re better than 90% of the window washers out there!
I scrape the length of the skylight in one go, but I’d recommend starting with small segments, like a finger length per scrape. Wipe the blade off and lightly scrub the skylight to keep it wet as needed.
Step four: prep work is done, now time to wash the window! Most of the tough stuff should be off by now, so give the glass a good scrub, and squeegee all the water off. Towel off the edges of the glass—I use surgical cloth, others like microfiber—then towel off the frame. Bam. Clean skylights. Brighter home.
You remembered to clean the roof off first, right?
A few notes.
Pollen left unattended can build up pretty thick. It will take a lot of elbow grease to scrub it off, or a quick pass with a razor.
Tree sap has to be razored. Try to scrub it hard and it will get in your scrubber cover, meaning every other skylight you “attemp” to clean will get some extra sap.
Concrete dust is awful. A little group the size of a pinhead is enough to cover a large pane in small scratches. You can try hosing the window off, but often times it’s stuck to the glass pretty well. Pull it straight off the glass with your fingernails if possible. Can be razored... But I wouldn’t recommend it unless you’re pretty confident on your blade abilities.
New construction. I once had a painter tell me that he didn’t worry about masking off glass because window washers can get any residue off no problem. That’s just the beginning of problems with new construction/remodel windows. Concrete dust, paint, varnish, stain, manufacturer stickers, dried cement, wood pulp, duct tape residue and a million other things can find their way on windows on construction sites. A lot of these mystery window blemishes laugh at razors. They scoff at Goo Gone, rubbing alcohol, and paint thinner. Save yourself the headache and hire professionals. Make sure they know it’s a new construction job and have experience with that type of work, because your average crew won’t.
Now excuse me while I get back to scraping stain off of sixty deck rails in 90° heat, because a certain painting company hasn’t yet mastered the difficult art of COVERING UP THE DAMN GLASS.
Have a nice day Oppo. Helicopter for your time, I’ll do a write-up for this crazy house eventually