Streak-free windows: the pros' 5-step method (and the right equipment)
You clean your windows carefully… and as soon as the sun hits them, the streaks come back. Don't worry: it's not about elbow grease. Professional window cleaners get a flawless result with a simple method and three tools: a strip washer, a squeegee and a lint-free cloth. Here's how to do it at home.
Why do streaks appear?
Streaks almost always have one of three causes:
- Too much product: excess detergent dries on the glass and leaves a film.
- The wrong cloth: paper towels and old tea towels spread dirt and leave lint.
- Air drying: water left to dry on its own leaves limescale rings.
The solution is to wet generously, remove the water in one clean stroke, then finish with a suitable dry cloth.
The equipment you need
- A bucket of lukewarm water with a few drops of washing-up liquid (no more!).
- A microfibre strip washer to loosen the dirt.
- A squeegee with a perfectly straight rubber blade.
- A lint-free cloth for the edges and finishing.
To get everything at once, our Streak-free window kit includes the squeegee, the 35 cm strip washer and the carbon fibre cloth.
The 5-step method
1. Dust first
Brush or vacuum the frame and sills. Otherwise, the dust turns into mud as soon as you wet the window.
2. Wet generously
Dip the strip washer in the bucket, wring it out lightly and run it over the whole surface, insisting on marks (fingerprints, insects, pollen). The window must be well wetted: the water is what carries the dirt away.
3. Squeegee in an “S” or in vertical strips
Place the squeegee at the top of the window, slightly tilted (about 30°), and pull down in one continuous stroke. Between strokes, wipe the blade with a cloth: that's the secret to not redepositing dirty water. Overlap each strip by 2 to 3 cm.
The “S” stroke (zigzagging from left to right without lifting the blade) takes a little practice, but it is very fast on large picture windows.
4. Finish the edges with a lint-free cloth
There is always a thin line of water along the frame. Blot it with a dry cloth that leaves neither fibres nor streaks, such as our 40 × 50 cm carbon fibre cloth, also perfect for mirrors and car windscreens.
5. Pick the right moment
Avoid washing windows in direct sunlight: the water dries too fast and leaves marks before you've even squeegeed. Choose an overcast day, the morning or the end of the day.
The result in the field
This is the method we use in our building cleaning work, including on large picture windows: wet, squeegee, then go over the edges and the bottom of the frames, where dust and water collect.
Picture windows photographed during one of our cleaning jobs.
What about high or hard-to-reach windows?
No need to balance on a stepladder. The telescopic window cleaning kit with swivel head combines a microfibre head and a squeegee on a detachable pole: you clean high windows and conservatories from the ground.
For very high areas (facades, glass roofs, solar panels), the 7 m water-fed telescopic pole with brush connects directly to your garden hose.
The trick for small surfaces
For shower screens, bathroom mirrors or car windows, the 3-in-1 squeegee with built-in sprayer sprays, scrubs and squeegees with one tool. One pass after each shower is enough to limit limescale.
Mistakes to avoid
- Using newspaper or paper towels: they leave lint and dirty your hands.
- Using too much product: a few drops of washing-up liquid per bucket are enough.
- Keeping a damaged squeegee blade: a nicked blade leaves a line of water on every stroke.
- Washing microfibre cloths with fabric softener: they lose their absorbency.
In short
Wet, squeegee, wipe the edges: with the right equipment, your windows are spotless and streak-free in a few minutes. Find all our tools in the Streak-free windows collection.