Streak-Free Window Cleaning

Goal

Clean windows without streaks. The whole job is technique: a streak-free window is a window cleaned with the right tools, in the right order, in the right humidity. Wrong tool (paper towels), wrong fluid (ammonia), or wrong day (high sun + low humidity = dries before you can squeegee) all produce visible streaks that the customer notices the moment the light hits.

Prerequisites

• Squeegee with rubber blade - Unger or Ettore brand, 12 - 14" residential
• Microfiber towels (multiple - wet, dry, glass-only)
• Window-cleaning solution (manufacturer pre-mix OR ½ cup vinegar + 1 gallon water + 1 tsp dish soap)
• Bucket
• Scraper (for dried paint or label residue - single-edge razor on a holder)
• 5 - 10 minutes per window once the technique is dialed in

Steps

1. Pick the right day. Avoid bright direct sun on the window - solution dries before you can squeegee, locking in streaks. Cloudy days OR morning/evening sun are ideal. Indoor windows can be done anytime.
2. Scrape any dried residue. Paint splatter, sticker residue, dried tape. Use a sharp blade angled flat against the glass. Move only forward; never back-and-forth (scratches the glass).
3. Pre-vacuum or brush the frame to remove dust + cobwebs. Loose debris turns into mud during washing.
4. Wet the glass with solution. Apply with a strip washer or sponge - generously. Cover the entire pane.
5. Squeegee. Start at the top-left corner, pull the squeegee to the top-right (left-handed cleaners reverse). Use a slight angle so water runs off the bottom of the blade.
6. Wipe the squeegee blade with a dry microfiber after each pass. A wet blade redeposits water on the next pass.
7. Continue down the window in overlapping horizontal passes. The blade should make contact with already-cleaned glass at each pass to pull all water down.
8. Detail the edges with a dry microfiber. The squeegee can't reach the perimeter of the frame; the corners + edges get streaks if not addressed.
9. Move to the next window. Don't let the previous one dry while doing this - verify by stepping back briefly.
10. Final inspection. From inside, look at the window from multiple angles. Visible streaks appear from one angle and disappear from another. If streaks are visible from any angle, re-do that section.

Verification

• No visible streaks from any angle
• No water pooling on the sill
• Frame clean of overspray + solution residue
• Customer can verify with their own inspection before paying

Troubleshooting

• Streaks running vertically: squeegee blade was wet on the next pass OR blade has a nick (run finger across to verify smoothness; replace blade if nicked).
• Streaks running horizontally: didn't overlap previous pass enough.
• Spots appearing after dry: solution was contaminated (oil from skin, dust) OR towels were too wet. Use fresh solution + fresh dry microfiber.
• Edge streaks: didn't detail the perimeter with a dry microfiber.
• Window dried before squeegeeing: too sunny OR too windy. Wet smaller sections at a time.

References

• IWCA (International Window Cleaning Association) best practices
• Manufacturer literature for cleaning solutions
• Manuall internal: Standard Residential Cleaning Service