Rain does the work: New glass coatings that actually stay clean?

I’ve actually worked with a couple of these coatings, both the older titanium dioxide-based ones and one of the newer “visible light” activated versions. The science behind them is pretty neat - photocatalysis basically means the coating reacts with light (usually UV), breaking down organic gunk so rain can rinse it off. The old-school stuff definitely needed a good dose of sun to work. Here in the Pacific Northwest, that’s not exactly reliable, right? I’ve seen plenty of disappointed homeowners who thought they’d never have to clean their windows again, only to find out moss and grime still build up, especially on north-facing glass.

The newer coatings claim to work with visible light, not just UV, so theoretically, cloudy days should still trigger the reaction. I’ve only installed a couple sets so far, but honestly, it’s too early to say if they’ll hold up long-term. The initial feedback’s been decent - windows seem to stay clearer between actual cleanings, but it doesn’t make them spotless. Stuff like pollen, mineral deposits from hard water, or sticky sap still needs some elbow grease.

One thing I’m curious about is how these coatings stand up to abrasion. In places with a lot of wind-blown grit or if you’re scrubbing to get rid of something stubborn, I wonder if the coating wears off faster. Also, not every installer preps the glass properly, which can mess with how well the stuff sticks.

Anyone else living somewhere with a ton of rain and not much sun tried these out for a full year or two? I’m all for less maintenance, but I’m a bit skeptical about the “set it and forget it” claims, especially in our climate.

Tried the visible light coatings on my south-facing windows last spring - honestly, they’re not a miracle fix. I noticed less streaking after rain, but pollen and hard water spots still stick around. If you’ve got trees nearby or wind kicking up grit, you’ll be scrubbing anyway. Prep matters a ton, too. If installers cut corners, forget it - the coating just flakes off. These are nice for reducing effort, but “maintenance-free” is wishful thinking in a rainy climate like ours.

You’re spot on about prep - surface contamination is the #1 reason these coatings fail early. I’ve seen a lot of jobs where installers skip the deep clean or rush the curing, and then the coating just peels after a season. One thing I’m curious about: did you notice any difference in how fast the glass fogs up? Some coatings seem to help with condensation, but I’ve also seen them make it worse if applied unevenly. As for the “self-cleaning” claim, yeah, it’s more like “slightly less dirty, slightly less often.” Still beats scrubbing every month, but it’s not magic.

That’s interesting about the fogging - I hadn’t even thought about that side effect. I’ve only used the older coatings and honestly, I didn’t notice much difference there, but they did seem a bit streaky after rain if the application was off. The prep thing is spot on; my friend tried a DIY kit and it just started peeling at the corners after one winter. I’m still skeptical about these new ones holding up in constant Seattle drizzle, especially if you can’t get a super clean surface to start with. If it really works better in low light though, maybe it’s worth another shot… but I’m not rushing out to buy unless I see some real-world proof.

I hear you on the skepticism, especially with the crazy amount of rain we get around here. I tried one of those “self-cleaning” coatings a couple years back (can’t remember the brand, but it was one of the ones that said rain would do all the work). Prep was a pain - lots of scrubbing and making sure there wasn’t any residue left. It looked great for maybe six months, but by the next winter, I started noticing weird streaks and some fogging around the edges. Not sure if I messed up the application or if it just doesn’t hold up to constant drizzle.

I’m curious if these newer coatings are actually any better, but like you, I want to see some proof before spending more money. Also, I’ve noticed that even with good prep, if your windows are older or have tiny chips or scratches, that’s where things start to peel first. Maybe these products work better on brand new glass? Hard to say. For now, I’m sticking with old-fashioned elbow grease and a squeegee... at least until someone shows me a window that’s stayed spotless through a Seattle winter.

Yeah, I tried one of those coatings too - think it was supposed to be “hydrophobic” or whatever. Looked awesome for a few months, then the grime started creeping back in, especially on the north-facing windows. Might just be our weather... nothing seems to last through all that rain. I’m with you, squeegee is still my go-to.

Looked awesome for a few months, then the grime started creeping back in, especially on the north-facing windows.

That’s been my experience too. I got all excited about these new coatings after seeing a demo at a home show - looked like magic watching water bead right off. But give it a season or two and, yeah, the rain and pollen seem to win out. Maybe it’s just our climate? I still keep a squeegee handy for the spring clean, even if the coating helps a bit in between. At least it makes the first few months feel fancy.

At least it makes the first few months feel fancy.

Funny, I had the opposite luck - my south-facing windows with the coating have been way easier to keep clean. Maybe it’s the extra sun baking off the gunk? North side is still a pain, though… nothing beats elbow grease there.

Funny how it works out differently for everyone. I’ve got a similar setup - south-facing windows with coating, and they’re definitely easier to wipe down. The north side? Yeah, that’s still a chore no matter what. I think you’re onto something with the sunlight helping out. Still, nothing replaces a bit of scrubbing when it comes down to it. If it makes the job even a little easier, though, I’ll take it.

I’ve noticed the same thing with my windows - south side gets more sun, and those coated panes almost clean themselves after a good rain. Here’s how I tackled the north-facing ones, since they never seem to stay clean for long:

1. I tested the coating on just one north window before doing all of them. It helped a bit, but not as dramatically as on the sunny side.
2. Tried leaving them after a rainstorm, hoping for that “self-cleaning” magic... but nope, still had to scrub.
3. I started wiping them down with a microfiber cloth every few weeks instead of letting grime build up. Way less elbow grease that way.

Honestly, I think sunlight does half the work on the south side. The coating helps, but if you don’t get much direct sun, you’re still in for some scrubbing. Maybe there’s a trick to applying it better on shaded windows? Or maybe it’s just wishful thinking that rain will ever do all the heavy lifting...

You nailed it - sunlight’s a game changer for those coatings. The tech is supposed to use UV to break down grime, so if your window never sees the sun, it’s kinda like having a self-cleaning oven that never heats up. I tried a similar coating on my north windows (old 60s ranch, big maples blocking most of the light), and honestly, it was only a slight upgrade from my usual “ignore until embarrassing” method. Rain just smeared the pollen around.

One thing that helped a bit: I gave the glass a super thorough clean before applying the coating, like borderline obsessive. Then I did a second coat after it dried. It stuck better and lasted longer, but yeah, still not magic. I keep a microfiber cloth stashed near the worst offenders and swipe them every couple weeks - less rage cleaning later.

If you ever find a trick that actually works for shady windows, I’m all ears. For now, I guess we’re just stuck doing a little manual labor where the sun don’t shine...

- Interesting take, but I’ve actually had better luck with hydrophobic coatings on my shady windows than the UV ones.
- They don’t break down grime, but they do help water bead up and roll off, which seems to keep the pollen from sticking as much.
- Not a total fix - still need to wipe them now and then - but I spend less time scrubbing.
- Prep is definitely key, like you said. If there’s even a hint of residue, nothing works right.
- Manual labor’s probably always part of the deal, but at least the right coating can cut down the frequency a bit... at least in my experience.

- I hear you on the prep - cleaning windows before coating is way more work than I expected.
- Hydrophobic coatings seem to last longer for me, too, but in the spring, pollen still manages to cling around the edges.
- UV stuff didn’t make much difference here, maybe because my windows barely get any sun.
- Still gotta wipe them down every few weeks, but at least it’s not a full-on scrub session each time... small wins, I guess.