Washing windows seems easy, doesn’t it? A bit of spray, a wipe, maybe a second go if it’s stubborn—and job done. That’s what I thought too, until I made every mistake in the book. More than once. My streaky panes, smudged corners, and surprise sun-baked stains taught me the hard way that not all cleaning methods are made equal—especially when it comes to glass.
One summer afternoon, armed with a bucket and determination, I decided to give my flat’s windows a proper clean. The sun was blazing, I was in a good mood, and everything seemed to go smoothly. That is, until the streaks started drying in faster than I could wipe. The more I tried to fix them, the worse they got. That was just the beginning.
Windows are a bit like mirrors—they don’t hide your mistakes. Every wrong cloth, badly timed spray, or sloppy angle shows up loud and clear once the light hits. And if you’ve got any upstairs windows, the risks go beyond smudges. Trust me, standing on a wobbly chair with one foot on the radiator isn’t worth the view.
So, to save you from my errors, I’ve pulled together the five things you should never do when washing your windows. Avoiding these missteps can mean the difference between a gleaming pane and a disaster of streaks, scratches or worse.
Let’s break it down, mistake by mistake.
1. Never Wash Your Windows in Very Warm and Dry Weather
The Sun Isn’t Your Friend Here
You might think a sunny day is perfect for window cleaning. Bright light to spot the dirt, lovely warm weather to work in, maybe even a bit of a tan while you’re at it. But there’s a hidden downside: the sun dries your cleaner too fast.
Window spray needs a few moments to loosen grime. On a hot, dry day, it evaporates in seconds. You barely have time to lift your cloth before it’s already left behind streaks. You’ll end up working twice as hard, re-spraying and wiping again, only to get uneven results.
And it’s not just about streaks. Quick drying can leave behind minerals and soap residue that etch faint marks into the glass over time. If you’ve got hard water, those minerals can be even more visible.
The Better Option
Pick a cool, overcast day instead. Early mornings or early evenings work well too. The idea is to give your cleaner time to work before it dries. If it’s summer and you’re desperate, work in the shade. Clean the windows on the shady side of the house first, then wait until the sun moves before doing the rest.
2. Never Use Paper Towels or Fibrous Cloths
Not All Cloths Are Made Equal
I used to think kitchen roll was the go-to for window cleaning. It’s disposable, it’s absorbent, and it’s right there in the cupboard. But paper towels are bad news for glass. They might soak up liquid, but they leave behind tiny fibres and lint. Those little bits cling to the pane and turn into an annoying fuzz, especially visible when sunlight shines through.
And don’t even get me started on old T-shirts or bath towels. They can be just as bad—fibres, dust, and sometimes tiny bits of fabric get stuck, and they don’t leave a clear finish. Plus, rough cloths can leave faint scratches on the glass, especially if there’s any grit involved.
What You Should Use Instead
Microfibre cloths are your best mate. They’re soft, lint-free, and designed to pick up dust and dirt without leaving a trail behind. Use one to clean and another to polish. You’ll get that crystal-clear finish you see in fancy hotel lobbies. Keep them clean, though—rinse them out often and don’t use fabric softener when washing, as it coats the fibres.
3. Never Spray the Entire Pane at Once—Especially on Big Windows
One Spray at a Time
Here’s another one I learned the messy way. If you’ve got a large window, don’t get carried away spraying the whole surface at once. You’ll think you’re saving time, but all you’re doing is giving yourself more chance to miss bits, leave streaks, or let some of it dry before you even reach it.
That first spray will start working immediately. But if you’re faffing around on one side while the other’s drying, you’ll have to go over it again anyway. Waste of cleaner, waste of effort, and it doesn’t even look good in the end.
Break It Into Sections
Treat the window like a grid. Spray a section you can manage in one go—maybe 30cm x 30cm—clean it, then move on. For big panes, think top left to bottom right or work in horizontal bands. That way, your cleaner doesn’t have a chance to dry before you’ve wiped it off properly.
This method’s especially helpful if your cleaner is strong or soapy. You’ll avoid build-up, and everything will dry evenly with fewer smears.
4. Never Clean Higher-Floor Windows Without Safe and Secure Footing
The Risk Isn’t Worth It
I’ll never forget the time my neighbour tried to clean her upstairs windows by leaning out with a squeegee in one hand and gripping the inside frame with the other. Brave? Maybe. Foolish? Absolutely. There’s no amount of dirt that’s worth a fall from the first floor.
Never attempt to clean upper-floor windows unless you’ve got the right setup. That means stable ladders, harnesses (if needed), or professional-grade poles if you’re doing it from the ground. Balancing on window sills or hanging halfway out with one foot in the air isn’t DIY—it’s dangerous.
Even leaning too far from an open window can mess with your balance. One slip, and you’re not getting back up.
What to Do Instead
Use extendable window cleaning tools from the ground or hire a pro. There’s no shame in calling someone who’s trained and insured. If you must do it yourself, make sure the ladder is on flat, stable ground, you’ve got someone holding it, and you’re wearing proper non-slip shoes.
And don’t try to be clever by stacking things like bins or stools underneath. I’ve seen it. It’s a recipe for broken bones and regret.
5. Never Clean From the Bottom Up
It’s Not How Gravity Works
This might sound obvious, but you’d be surprised how many people start at the bottom of the pane. It seems logical—clean the bits you can reach, then work upwards. But here’s the thing: water runs down. If you clean the bottom and then the top, that lovely upper section will drip straight over the area you just did.
So you’ll either have to do it again or put up with drying dribbles that ruin the finish. Worst of all, you’ll get frustrated, and frustration leads to shortcuts—and shortcuts lead to streaky glass.
Always Start at the Top
Begin at the top and work your way down. That way, any drips are wiped away as you go. It’s more efficient, and your end result will actually look clean from top to bottom.
This applies to spraying, too. Start high, spray lightly, and let gravity work with you. You’ll waste less cleaner and get a smoother finish.
Final Thoughts
Washing windows isn’t rocket science, but it’s easy to mess up if you’re not paying attention. The worst part? You won’t always notice until the light catches a streak or you spot a smudge from the sofa later on. A few simple changes to your routine can make all the difference.
Wait for a cool day. Use the right cloth. Tackle one section at a time. Keep your feet on solid ground. And start from the top, not the bottom. That’s it. Stick to those five rules, and you’ll be left with panes so clear you’ll forget they’re even there.
If you’re still stuck staring at watermarks and wondering what went wrong, give it a rest and ring someone who cleans for a living. We don’t mind taking over—and we’ve made all the mistakes already so you don’t have to.