When a professional window cleaner shows up to a job, they’re not just wiping glass. They’re scanning every window for the things that determine whether a cleaning will even help. Most homeowners don’t notice these signs until they become expensive — etched glass that won’t come clean, foggy panes that block light, frame rot that’s spread for years.

Here are seven things our crews catch on the job that you can spot yourself before booking a clean. From a NJ and NY metro window cleaning company that’s looked at more glass than we can count.

Sign 1: Cloudy or Hazy Spots That Won’t Come Off

You clean a window. The glass still looks hazy in spots, especially in direct sunlight. The professional cleans it. Same result.

That’s mineral etching — usually from years of sprinkler spray, hard tap water, or window cleaner residue. Once minerals etch into the glass surface, no amount of cleaning brings it back. The fix is either professional etching removal (works for light cases) or replacement (for severe cases). Our blog on hard water and your windows covers the cause side.

Sign 2: Fog or Condensation BETWEEN the Panes

Condensation on the inside of a window in winter is normal — it’s about humidity and temperature. Condensation between the two panes of a double-pane window is not. It means the seal between the panes has failed and outside air is leaking into the gas-filled cavity.

Cleaning will not fix this. The window has lost its insulation value and is on its way to becoming a fully fogged pane that you can’t see through. The fix is either glass-unit replacement (the IGU, not the whole window) or full window replacement, depending on age. If you see fog between the panes on more than 1–2 windows, the seal failure is usually progressive — expect more to fail in the next few years.

Sign 3: Scratches on the Glass

Scratches happen from construction debris that didn’t get cleaned off post-build, from using metal scrapers wrong, from pets, from kids with toys. Light surface scratches can often be polished out. Deep scratches usually can’t.

If you’ve got a scratched window that’s been bothering you, our window scratch repair service handles light-to-medium damage that doesn’t require full replacement. For severe cases, replacement is the cleaner answer — a scratched piece of expensive glass is more expensive to live with than to fix.

Sign 4: Frame Rot or Soft Wood

Wood window frames — especially on older Bergen, Westchester, and Hudson Valley homes — eventually rot if they’ve been getting water exposure. Push a finger or screwdriver tip into the bottom corner of a wood frame. If the wood gives, dents, or crumbles, that’s rot.

Window cleaning won’t touch this. Rot needs either wood replacement (epoxy fill for small areas) or full sash/window replacement. Catching it early is the difference between a $200 carpentry repair and a $1,200 window replacement. Our blog on preventing window damage goes deeper on the causes.

Sign 5: Screens That Crumble When You Touch Them

Window screens have a service life of usually 10–15 years. After that, the mesh starts breaking down. UV light degrades it, pollen builds up in it, and small tears spread.

The test: take a screen out and gently flex the mesh. If it crumbles, has visible holes, or the corners are bent and corroded, it’s past saving. Cleaning won’t fix it. Replacement screens are cheap; living with torn ones means bugs, drafts, and dirt buildup on the glass behind them. Our post on why screen cleaning matters covers the maintenance side.

Sign 6: Sticking Sashes or Failing Hardware

A window that won’t open without serious force, won’t stay open without something propping it up, or whose lock doesn’t quite engage isn’t a cleaning problem — it’s a hardware problem. Sash cords broken, balances worn out, locks corroded, hinges sagging.

These are fixable, usually for less than people expect. A handyman or window pro can replace balances and hinges. But it’s also the kind of thing that quietly gets worse, and a stuck window in a fire is a real safety issue. If it sticks, address it.

Sign 7: Stained or Damaged Window Tracks

Look at the bottom track of a double-hung or sliding window. Black or green staining you can’t wipe away is usually mildew that’s set into the surface, often a sign of trapped moisture. Pitted or corroded aluminum tracks point to long-term water exposure. Cracked vinyl tracks point to UV degradation.

Tracks alone don’t doom a window, but they’re a leading indicator. Tracks that look bad usually mean the seal around the window has issues somewhere — worth a closer look.

Bonus: Drafts You Can Feel

On a windy day, run a hand around the frame of every window in the house. If you feel cold air coming in, your window seal is compromised somewhere — usually around the frame, sometimes between panes. The EPA’s guide to indoor air quality covers why this matters for comfort and energy bills, but the practical impact is your heating and cooling running harder than it should.

What to Do Next

If you spotted one of these on your house, here’s the quick triage:

• Etching, scratches, mineral haze: Specialty cleaning or scratch repair. Sometimes glass replacement.
• Fog between panes, seal failure: Glass unit replacement or full window replacement. Not a cleaning fix.
• Frame rot: Carpentry repair or sash/window replacement. Address fast — it spreads.
• Screen damage: Replace the screens (cheap). Pair with the next cleaning visit.
• Hardware failure: Window pro or handyman. Inexpensive compared to replacement.
• Drafts and tracks: Diagnostic visit to find the air-leak source. May involve weather-stripping, caulking, or larger work.

Routine cleaning still matters — keeping the glass and screens clean prolongs the life of the whole window system. If you’re due for a maintenance visit, our regular residential window washing includes a quick visual check for these issues so you find them before they get expensive, and we can flag anything we see for follow-up.

Ready for a Real Look at Your Windows?

If something on this list rang a bell, we’d be happy to walk through your house and tell you which windows need cleaning, which need scratch repair, which need replacement, and which are fine. Request a free estimate and we’ll send a real assessment — across Bergen, Essex, Passaic, Rockland, and Westchester.