A perfectly clean window is one you stop noticing. You look through it rather than at it. Streaks do the opposite: they announce themselves the moment the sun comes round the side of the house, turning a decent job into a patchy one. The encouraging part is that streak-free glass has very little to do with expensive products. It comes down to the order you work in, the water you use, and a squeegee you can actually control. Get those three things right and most windows take a few minutes each.
You need surprisingly little to start, and good tools last for years if you look after them. A cheap squeegee with a hard, curling blade is the single most common reason beginners blame themselves for streaks that are not their fault.
Most streaks begin before you get started. Dust and grit, when wetted, become a thin milky film that dries into a haze. Work in this order instead:
Avoid direct sunlight and hot glass. If the solution dries before you can squeegee it, you are not cleaning, you are painting on a film. Early morning, late afternoon or a shaded side of the building will always give you a better result.
Hold the squeegee so the blade meets the glass at roughly 30 degrees. Too flat and the water sits behind the rubber; too upright and it chatters and skips across the pane. Keep the top corner of the blade slightly ahead of the bottom corner so the water is pushed downwards and sideways rather than pooling in the middle.
Start at the top left corner, pull across, then return for the next pass and overlap the previous stroke by a couple of centimetres. Every stroke should start on dry glass and finish on wet glass, which sounds fussy until you try it — it is the difference between a clean line and a smeared one. Wipe the blade on your cloth after every stroke. A wet blade simply redistributes dirty water.
The final stroke is the one people see. Work down one vertical edge in a single continuous pull, then dry that edge immediately. This “framing” habit leaves you a clean border to work back from, and it stops water creeping out of the sides while you finish the middle.
If the blade squeaks dryly, you have taken too much water off. If it leaves a mist, you are pressing too lightly. Aim for a soft, steady, even sound across the whole pane.
Glass dries fastest at the edges, and that is where the visible lines appear. Water also gathers in the corners of the frame and then dribbles back down minutes later, undoing your work.
Interior panes are usually only marked by fingerprints and cooking film, so they need a lighter touch. Mist a little diluted detergent onto the glass, work it over with one cloth, then buff dry with a second, dry cloth. Wring cloths out so they are damp rather than dripping; painted and wooden frames do not appreciate a soaking, and sills should always be dried after wiping. On uPVC, a damp cloth is fine, but wipe the sill dry so dust does not bake into the surface. If your window frames are timber and the finish is already flaking or soft, it is worth speaking to a decorator or joiner before you add more water to the problem.
Work top to bottom and frames before glass. Wet, scrub, squeegee in overlapping strokes, wipe the blade every time, dry the edges, then dry the sill. Keep the kit clean, store the squeegee so nothing presses against the rubber, and replace the blade when it stops cutting water cleanly. Two or three passes a year suits most homes; more often if you live on a busy road, near the coast or beside trees that drop sap.
Most importantly, be honest about height. If windows are awkward to reach, or you are not comfortable up a ladder, that is a job for a professional — and it is far cheaper than a fall. Everything at ground level and within easy reach, though, is well worth learning to do properly. Once the technique clicks, you will notice it in every window rather than on every window.
Photo: StockSnap / Pixabay
