The secrets to streak-free windows
Anyone can make a window wet. Making it perfectly, invisibly clear — no streaks, no haze, no lint catching the afternoon light — is a different skill entirely. We can tell you the secret isn't an expensive product. It's technique, timing, and a few small habits that make all the difference. Here's how the pros do it.
Secret 1: Never clean in direct sunlight
This is the single most common mistake. When the sun warms the glass, your cleaning solution evaporates before you can wipe it away, leaving behind the very streaks and spots you're trying to remove. Always work on cool glass — early morning, late afternoon, or on an overcast day. If a window is in full sun, start somewhere shaded and come back to it later. This one change eliminates most streaking on its own.
Secret 2: Less solution, not more
It feels counterintuitive, but flooding the glass with cleaner makes things worse. Excess detergent leaves a residue that dries to a film, and the more suds you create, the more you have to remove. A few drops of dish soap in a bucket of clean water is all most windows need. Save the heavy-duty products for genuine problems like sap or mineral staining.
Pro mix: a gallon of cool water with a small squirt of dish soap. That's it. Greasy kitchen windows can take a touch more; everyday glass takes less.
Secret 3: Ditch the paper towels
Paper towels and newspaper shed lint and break down when wet, smearing fibres across the glass. Professionals use two things: a quality squeegee for the main pane and a microfibre cloth for edges and detailing. Microfibre lifts and traps residue instead of pushing it around, and it won't leave fibres behind. Keep a dedicated set just for glass, and wash them without fabric softener (which leaves a film).
Secret 4: Master the squeegee stroke
The squeegee is where streak-free magic happens — if you use it correctly. Wet the whole pane first. Then, starting at a top corner, pull the squeegee across in a smooth, slightly overlapping stroke, wiping the rubber blade with a clean cloth after each pass. Overlapping each stroke into the area you just cleared is what prevents those telltale lines. Finish by running a dry microfibre around the edges to catch any drips.
Secret 5: Work top to bottom
Gravity is your friend if you respect it. Always clean from the top of the window downward, so drips fall onto glass you haven't finished yet rather than onto your nice clean lower section. The same logic applies to a whole house: do upper floors before lower ones where practical.
Secret 6: Don't forget the frames and sills
Spotless glass framed by dusty, grimy edges never looks truly clean. Wipe down frames, sills, and tracks before or after the glass so the whole window reads as fresh. A soft brush is handy for getting dust out of corners and runners. It's a small step that dramatically lifts the finished result.
The professional edge: purified water
Here's a secret you can't easily replicate with a bucket: professionals often use purified (deionised) water. Ordinary tap water contains dissolved minerals that dry into spots — that faint cloudiness you sometimes see after a DIY clean. Purified water has those minerals removed, so it dries naturally clear with no residue at all. It's also what lets us safely reach high windows with extension poles, no ladder required. This is a big part of why a professional clean simply lasts longer and looks sharper than the DIY version.
Streak-free isn't about scrubbing harder. It's about cool glass, the right tools, and a disciplined stroke.
Common mistakes to avoid
- Cleaning hot, sun-baked glass
- Using too much soap or harsh sprays
- Reusing dirty cloths that just redistribute grime
- Skipping the frames and sills
- Pressing too hard and chattering the squeegee
When to call a pro
DIY is great for accessible, ground-floor windows on a calm day. But for high or awkward windows, hard-water staining, or simply getting your weekend back, a professional clean pays for itself in time and results. If you're weighing up the wider benefits, our piece on why clean windows quietly boost your home is worth a read — and if you're wondering how regularly to keep this up, see how often you should really clean your windows. You can also explore our full range of services.
Want flawless results without lifting a squeegee? and let us do the work.