Quick answer: Clean windows in the shade or on a cloudy day when the glass is not hot. First, remove dust and wash the frames, then apply an appropriate amount of glass cleaner. For large panes, use a clean rubber squeegee from top to bottom, wiping its edge after each stroke. Finally, dry the edges of the glass with a clean, lint-free cloth.
Updated: August 2026
Why streaks appear after washing
Streaks are usually a mixture of dissolved grease, excess product, and water that has dried on the glass before you could remove it. Direct sunlight and warm glass accelerate evaporation. The result can also be worsened by a dirty cloth, a worn squeegee blade, or too much cleaner.
The most common causes are:
- washing a hot window in direct sunlight,
- smearing dust without prior removal,
- too much cleaning agent,
- using one cloth for both frames and final polishing,
- a dirty or damaged squeegee,
- undried edges and corners of the glass.
What to prepare for window cleaning
- a duster or vacuum cleaner with a soft attachment,
- a bucket of lukewarm water,
- a soft cloth for frames,
- a separate clean microfiber or lint-free cloth for glass,
- a cleaner designed for glass and mirrors,
- a rubber squeegee for larger panes,
- a dry cloth for edges and the windowsill,
- gloves according to product label instructions.
Do not use steel wool, abrasive sand, hard scrapers, or solvents not approved by the window manufacturer. For tinted glass, films, and special coatings, always check the manufacturer's instructions.
When is the best time to wash windows?
An overcast day without rain, or part of the day when the window is in the shade, is ideal. The glass should be cool to the touch. In the sun, the cleaner can dry before you wipe it off, leaving marks.
In freezing temperatures, avoid very hot water. A sudden temperature difference is not good for either the glass or the frames. Strong winds can also cause the surface to dry faster and make working at height less safe.
How to wash windows step-by-step
1. Clear the area and consider safety
Move plants and decorations, pull up blinds, and remove curtains or screens as needed. Place an absorbent cloth under the window. Do not lean out of the window or use an unstable chair. For inaccessible exterior windows, choose an appropriate telescopic tool or professional service.
2. Remove dust dry
Vacuum or wipe dust from frames, hinges, grooves, and the windowsill. If you skip this step, water will turn the dust into a gray slurry that you can easily transfer to the glass.
3. Wash frames and windowsill
Clean frames with a soft cloth and a product suitable for their material. White PVC, lacquered wood, and aluminum may require different care. Rinse the cloth frequently and change the water as soon as it becomes dirty.
Wash the frames before the glass. Otherwise, drips from the frame could re-dirty an already polished pane.
4. Pre-wash heavily soiled glass
Gently wash the exterior side with dust, pollen, and dried dirt with lukewarm water first. This reduces the risk of hard particles scratching the surface during polishing. Do not remove insect residue forcefully when dry—let it soften first.
5. Apply glass cleaner
Use just enough product so that the surface can be cleaned evenly. For smaller panes and mirrors, a small amount of spray and a clean microfiber cloth is sufficient. If you want to protect a delicate frame or windowsill, spray the product onto the cloth first.
For regular household use, you can choose E07 Window and Glass Cleaner, which is color and fragrance-free, or G51 Uni Shine with a citrus scent. An environmentally certified option is VERDE ECO VETRI E SPOLVERO with EU Ecolabel; the spray nozzle is not included with this packaging.
6. Squeegee water from top to bottom
For a large pane, place a clean squeegee against the top edge and guide it in a continuous stroke downwards. Overlap the next stroke slightly with the previous one, and wipe the rubber edge dry after each stroke. This prevents the squeegee from returning dirty water to the cleaned area.
7. Dry edges and inspect the glass
Wipe corners, the bottom edge, and any drips on the frame with a clean, dry microfiber cloth. Inspect the glass from different angles. If you see a faint mark, polish only the affected area with a dry part of the cloth—do not automatically add more product.
Spray, microfiber, or squeegee?
- Spray and two cloths are practical for smaller windows, mirrors, and fingerprints. The first cloth cleans, the second dries.
- Applicator and squeegee are faster for large panes and balcony doors.
- Concentrate makes sense for larger areas and frequent professional use, but requires precise dilution.
For larger operations, for example, MD11 ultra-concentrated cleaner is intended, which is diluted to a 4% solution according to the label. Higher concentration is not automatically more effective; incorrect dosing, on the contrary, promotes film formation and unnecessary waste.
How to clean very greasy or dull glass
A kitchen window may have a greasy film in addition to dust. First, remove coarse dirt, then work in smaller sections and change the cloth more frequently. For stronger cleaning of glass, mirrors, stainless steel, and other shiny surfaces, G02 Lesk Forte Premium is available. It contains ammonia, so ventilate when working on a larger area and check manufacturer's instructions before use on tinted or treated glass.
Common mistakes when washing windows
- Polishing with newspapers: printing ink and paper fibers can leave marks; clean microfiber is more predictable.
- One rag for everything: grease from the frame will transfer to the glass.
- Adding product with every streak: often, a dry clean cloth is enough.
- Dirty water: change it before it turns gray.
- Too much pressure on the squeegee: a straight, smooth stroke and an undamaged rubber blade are more important.
- Ignoring the label: use the cleaner only on recommended surfaces and do not mix it with other products.
Frequently asked questions
How to wash windows without leaving streaks?
Work on cool glass, use clean tools, a small amount of cleaner, and dry the surface completely. For large windows, squeegee water from top to bottom and wipe the rubber after each stroke.
Is microfiber or paper towel better?
Quality clean microfiber usually sheds fewer fibers and can be reused. Paper towels are suitable for small areas if they are strong and do not leave lint.
Can I wash windows in the sun?
You can, but the result is usually more challenging because water and cleaner dry quickly. For easier work, choose shade or a cloudy day.
How do I know which side has the streak?
During the final inspection, you can polish the inside vertically and the outside horizontally, for example. Based on the direction of the mark, you can then more easily tell where a touch-up is needed.
How often should windows be washed?
There is no fixed interval. It depends on proximity to roads, pollen season, weather, children, and pets. Complete washing is usually needed several times a year in a household; fingerprints on the inside can be removed as needed.
Clean windows without unnecessary effort
The best results come from the correct order and complete drying of the glass. Start with dust and frames, continue with a suitable glass cleaner, and finish with a clean squeegee or dry microfiber. When the glass is not hot and the tools are not dirty, you need less product and fewer touch-ups.
