How to Clean Windows Streak-Free

Everyone has stood back from a window they have just cleaned, caught the light at the wrong angle and seen a sea of smears looking back at them. The frustrating part is that streaks are almost never about effort — they come from the wrong cloth, the wrong solution, or drying too slowly in the sun. Get the method right and a window takes a couple of minutes and comes up perfectly clear. Here is the approach we use on homes across Auckland.

What you need

You do not need much, but the right kit makes all the difference. A good rubber-bladed squeegee is the single most important tool — it is what separates a streaky finish from a flawless one. Add a bucket, a microfibre cloth or a window scrubber (an old-fashioned sponge works too), a lint-free cloth or a clean microfibre for edges, and a solution. Avoid paper towels and newspaper: they shed fibres and leave lint behind.

The best cleaning solution

You can keep it simple. Warm water with a few drops of dish soap lifts grime beautifully — the trick is to use only a tiny amount, because too much soap is itself a cause of streaking. For glass that has water spots or a film, add a good splash of white vinegar to the mix; it cuts through mineral deposits that plain water leaves behind. Commercial glass sprays work fine for a quick touch-up on one or two panes, but for a whole house the bucket-and-squeegee method is faster and far more consistent.

The best day and time to clean windows

This is the step most people miss. Never clean windows in direct sunlight. The sun dries the solution before you can squeegee it off, and that half-dried film is exactly what shows up as streaks. Pick an overcast day, or work in the shade — do the sunny side of the house early or late when it is out of direct light. A still, cool day is ideal.

The squeegee method, step by step

Start by dry-dusting or brushing the frame and sill so you are not dragging grit across the glass. Wet the whole pane generously with your scrubber, working top to bottom and loosening any stuck-on dirt. Now the squeegee: tip the top edge of the blade against the glass at the top-left corner and pull straight down in one smooth stroke. Wipe the blade on a dry cloth, overlap the previous stroke by a few centimetres, and pull the next one. Repeat across the pane. Finish by running the squeegee along the bottom edge, then wipe the sill and the thin border of the glass with a dry lint-free cloth to catch any drips. That border wipe is what gives a truly professional, edge-to-edge finish.

Inside vs outside

Inside glass is mostly dust, fingerprints and kitchen film, so it needs less solution and a gentler touch. Outside glass takes the weather — pollen, salt spray near the coast, road grime and bird mess — so it needs a more thorough wash and usually that splash of vinegar. A handy tip: squeegee the inside of each pane with horizontal strokes and the outside with vertical ones. If a streak shows up afterwards, you will know instantly which side it is on. Do the insides yourself and you will often find the real difference is on the outside — which is where the height and access start to matter.

When to hand it to a professional

There is a limit to what you can safely reach from a ladder — upper-storey windows, joinery over a deck or stairwell, and large feature panes are genuinely risky to do yourself. For the glass you can reach, a professional window clean as part of a regular or one-off home clean takes the job off your list: we clean the frames, tracks and sills as well as the glass, inside, and outside with a hose, brush and squeegee, so the finish stays cleaner for longer without streaks.

Clean windows are also one of the quickest ways to make a whole home feel brighter and better kept — a point worth remembering alongside the damp and ventilation habits in our guide to removing black mould, since the same window reveals and seals are where both problems show up first.