How to clean windows without streaks
About 6 minutes to read. Published . By the House & Hedge team.
Streaks on windows are rarely about the glass. They come from the method. The cleaner dries too fast on a warm pane, a cloth carries grime from one place to another, or a drying cloth that is already damp smears the wet solution across the glass rather than lifting it off. A simple routine, with the right timing and a clean cloth for each stage, gives a clear, streak-free finish. The same method works on glass doors, conservatory panels and mirrors.
What you need
- Two microfiber cloths, one for washing and one for drying, both clean
- A bucket of warm water
- Either a window cleaner, or a mix of white vinegar and water in a spray bottle
- A soft brush or a sponge for the frames and sills
- A squeegee with a rubber blade, for large panes
- A bucket and a small brush for the frames, if they are heavily soiled
Timing and conditions
Clean windows on a cloudy day, or in the shade, or early in the morning before the sun reaches the glass. Direct sun dries the solution on the surface before you can wipe it, and the residue it leaves is what streaks. A windy day can also dry the glass unevenly, so choose a calm time if you can.
Start at the top of the window and work down. Drips from the upper parts run onto areas you have already cleaned, so the bottom of the glass comes last.
Cleaning the glass
- Wash the glass with a cloth dampened in the cleaner or in warm water with a small amount of dish soap. Use a little solution rather than a lot, because excess liquid runs down the glass and leaves lines.
- Wipe in one direction across the pane, such as side to side, then wipe the next pass in the other direction. The change of direction shows you where you missed a patch.
- Use the squeegee on large panes. Hold it at a slight angle, pull it down in a single smooth stroke, and wipe the blade clean with a cloth after each pass. Overlap each stroke slightly.
- Buff the glass with a dry microfiber cloth, moving across the pane until it is dry and clear. This last stage removes the thin film that causes streaks.
If the glass has a light film of grime, a vinegar and water mix (one part vinegar to one part water) works well. For a heavier film, use a window cleaner, following the label.
Hard water spots
White spots that do not wipe off are hard water mineral. Mix equal parts white vinegar and water, spray it on the spot, leave it for a few minutes, and wipe. For stubborn spots, use a cloth dampened in the vinegar mix and hold it on the spot for a few minutes before wiping.
If the spots remain after this, the glass may be etched. Etching is a permanent change to the surface, and it does not come off with any cleaner. A professional glass company can polish light etching, but deep etching needs new glass.
Cleaning the frames and the sills
Clean the frames and sills before the glass, so dirt does not drip onto the clean panes. Dust the frames with a dry brush first, then wipe them with a cloth dampened in warm soapy water. Use a soft brush in the corners and the tracks, and dry the frame with a cloth.
For painted frames, use a mild soap and avoid harsh cleaners, which can dull the paint. For uPVC frames, use warm soapy water and a soft cloth, and avoid abrasive pads, which scratch the surface.
Tracks and sliding windows
Sliding windows collect grit in the tracks, and grit scratches the glass as the window moves. Vacuum the track with a narrow nozzle, then brush it with an old toothbrush dipped in warm soapy water. Dry it with a cloth, and check the wheels for debris. A clean track runs more smoothly, and it does not drag grime onto the glass.
Outside glass and windows you cannot reach
Clean the outside of upper windows from the ground or from a balcony where it is safe, using a pole with a brush or a squeegee head rather than a ladder if you can. A pole gives you reach without the danger of standing on a ladder with a bucket. Keep the pole and its attachments clean, and rinse them often, because grit caught in the brush scratches the glass.
If you must use a ladder, set it on firm, level ground, lock its spreader, and have someone hold the foot. Never lean out to one side while standing on a ladder, because the ladder can tip. Do not clean windows in wind, rain or ice. For a window that is high, unusual or on a shaped building, a window cleaning service is a safer and often quicker choice.
Why glass gets dirty so fast
A film builds up on outside glass in a busy street or near a road, from exhaust, dust and pollen, and it bonds to the glass when it rains. Inside glass gets a different film from cooking, smoking, humidity and the soft plastics in furnishings. A dirty film shows up as a haze that looks like streaks no matter how carefully you wipe.
To clear a film, use a little more cleaner on the first pass and wipe twice, once to lift the grime and once to buff it away. Clean the glass more often in those conditions, because a thin film is much easier to remove than a thick layer built up over months.
Tinted glass and film
Window tint is a film applied to the inside of the glass, and some cleaners damage it. Ammonia-based cleaners can cloud or lift the film, and vinegar can do the same over time. Use a mild soap and water, or a cleaner made for tinted glass, and check the film’s care advice.
Glass doors
Glass doors take the same method. Pay extra attention to the handles and the bottom edge, where fingerprints and dirt collect. Clean the frame and the track as described above, and check the seal for debris.
Common mistakes
- Cleaning in full sun, which dries the solution before you can wipe it.
- Using too much cleaner, which runs down the glass and leaves lines.
- Drying with a damp cloth, which smears the film rather than lifting it.
- Using a dirty cloth, which carries grime back onto the glass.
- Cleaning the glass before the frames, so dirt drips onto clean panes.
- Using paper towels, which can leave lint and tear, and which are less absorbent than microfiber.
Keeping the windows clean
Wipe the glass around door handles and light switches each week. Clean the glass every month or two, and clean the frames and tracks at the same time. A squeegee run across a pane after rain or after a shower keeps the glass clear between full cleans, especially on a window that gets a lot of splashes.
When to call a professional
If the glass is cracked, if the seal between the panes has failed and the glass has misted inside, or if a window is hard to open or close after cleaning, call a window specialist. Misting between the panes cannot be cleaned away, and the unit needs replacing.
