Why your windows look streaky, and how to fix it

Streaky windows are almost always down to method rather than the glass itself. The three usual causes are using too much cleaning product, cleaning with the wrong cloths, and letting the glass dry too fast in direct sun. Fix those and you get clear, streak-free results. Professionals also use pure water systems that dry spot-free without any buffing at all.

The common causes of streaks

• Too much product: excess cleaner leaves a residue that smears as it dries.
• Direct sunlight: the solution dries before you can clear it, leaving marks.
• The wrong cloth: paper towels and old cotton rags leave lint and smears.
• Dirty water or cloths: you just move grime around.
• Skipping the edges: product pooling at the edges dries into lines.

How to get streak-free glass

1. Clean on a cool, overcast day or in the shade.
2. Use a small amount of product, more is not better.
3. Wash with a microfibre cloth or applicator, then clear with a squeegee.
4. Wipe the squeegee blade between strokes.
5. Buff any edges with a clean, dry microfibre cloth.

Why professionals get it right every time

Window cleaners increasingly use water-fed poles with purified water. Because the water has no minerals, it dries without leaving spots or streaks, so there is no buffing and no ladders for upper floors. It also explains why professional results look so consistently clear, see our comparison of traditional and water-fed pole cleaning.

Clear windows, less often

Regular cleaning also helps, because glass that never builds up heavy grime is easier to keep clear, see how often to clean your windows. If you would rather skip the streaks entirely, our window cleaning service leaves glass, frames and sills spotless across Derby and the surrounding towns.