Why Your Windows STILL Have Streaks After Cleaning

You followed the instructions. You bought the "streak-free" cleaner. You watched the videos. You spent an hour on a Saturday morning carefully cleaning every window in the house.

Then the afternoon sun came through and there they were. Streaks. Everywhere.

After 25 years of cleaning windows professionally, from residential homes in Melbourne to high-rise buildings in Vienna, I can diagnose window streaks the way a mechanic diagnoses engine noise. And in almost every case, the cause is one of seven things that nobody talks about.

Cause #1: You're Using the Wrong Cleaner

Your "streak-free" glass cleaner is probably creating the streaks. The fix: a few drops of dish soap in a bucket of water.

Cause #2: Too Much Soap

More soap does not mean cleaner windows. Excess soap creates a film on the glass.

Cause #3: Your Water Is Working Against You

If your tap water has high mineral content, those minerals stay on the glass as white spots.

Cause #4: You're Cleaning in Direct Sunlight

When sunlight hits wet glass, the cleaning solution evaporates faster than you can squeegee it off.

Cause #5: You're Using the Wrong Tools

Paper towels leave streaks. Always. Without exception. What actually works is a squeegee, scrubber, and microfiber cloth.

Cause #6: Your Squeegee Technique Is Off

Wrong angle. Stopping mid-stroke. Not wiping the blade between passes.

Cause #7: You're Detailing Wrong (Or Not At All)

The last 10% of the job creates 90% of the visible streaks. One pass with a lint-free microfiber cloth along each edge.

The Quick Diagnosis

• Streaks everywhere: Too much soap or wrong cleaner
• White spots or cloudy film: Hard water minerals
• Streaks that appear quickly: Sunlight evaporation
• Tiny fiber marks: Paper towels or cotton cloth
• Lines running vertically: Edge water dripping down
• Random streaks: Dirty squeegee blade

The streaks end here. Download "The Window Cleaning Manifesto", FREE 5-minute training.