Most streaks are not dirt left behind. They are cleaner left behind: a thin film of soap or spray that dries before it is removed and shows up the moment the sun hits the glass. The fix is less product, a better tool, and a different order of work.
Why streaks happen
- Too much product. Spray cleaners are made to be wiped off. When you use more than the cloth can lift, the rest dries on the glass.
- The wrong cloth. Paper towels leave lint, and cotton cloths push water around instead of lifting it.
- Sunshine. Glass in direct sun dries in seconds, before you have finished the pane.
- Hard water. Tap water with a lot of minerals leaves white spots as it dries.
The method our crews use
Pick the shady side and the cool hour
Clean windows when the glass is out of direct sun. On a south-facing window that means early morning or late afternoon.
Dust the frame and sill first
Brush or vacuum the frame and the sill before any water goes near them. Wet dust turns into mud that runs down the clean glass.
Wash with a bucket, not a spray
A bucket of warm water with a few drops of washing-up liquid, about one teaspoon to five litres. Wet the whole pane with a strip applicator or a sponge.
Squeegee in one direction
Start at the top corner and pull the squeegee down or across in overlapping strokes, wiping the blade with a dry cloth after each one.
Detail the edges with dry microfibre
Wipe the edge of the pane, where the squeegee could not reach, with a dry microfibre cloth folded into a pad.
The whole pane takes about a minute this way, and the squeegee removes the water before it can dry.
What you need
- A 30 to 35 cm squeegee with a fresh rubber blade.
- A strip applicator or a large sponge.
- Two microfibre cloths: one for the blade, one for the edges.
- A bucket and washing-up liquid.
- Distilled water for the last rinse if your water is hard.
What changes when a pro does it
The method is the same. What changes is reach, time, and the outsides.
Height. Upstairs outsides are the reason most people book. Our crews use water-fed poles from the ground for most homes, so there is no ladder against your walls and no one leaning out of a window.
Water. The pole systems run purified water with no minerals in it. It dries without spots, so the glass is rinsed rather than squeegeed, which is why frames and sills come out clean too.
Time. A three-bedroom house with 20 panes, inside and out, takes one of our technicians about two hours. The same job at home, with a ladder, usually takes a weekend afternoon.
Fixed parts. Tracks, seals, and screens are where dead insects and grit live. They are on our window cleaning ticket and easy to skip on your own.
How often
Twice a year is enough for most homes: once in spring after the pollen, once in autumn before the dark months. Homes near a main road or the sea benefit from four visits a year, because traffic film and salt build up faster.
Written by
Marco D.
Crew lead, cleaning
Leads a cleaning crew in Elm Park and writes the checklists the crews work from.
