Pre-wash with soapy water and rinse thoroughly before final cleaning

For heavily soiled exterior windows, a soapy pre-wash removes caked-on dirt, pollen, and grime so the final streak-free cleaning step can work on a clean surface instead of pushing debris around.

Steps

1. Mix a few drops of liquid dish soap into a bucket of warm water.
2. Scrub the window with a soft brush or sponge to loosen heavy dirt.
3. Rinse thoroughly with clean water — use a hose for exterior windows. Soap residue left on the glass is a primary cause of streaks.
4. While the glass is still damp, follow up with a vinegar-water spray and squeegee, or a commercial glass cleaner, for the final streak-free pass.

Why It Works

Heavy grime acts as an abrasive and contaminant during the final cleaning step. Removing it first means the finishing cleaner only has to deal with a thin film of water and minor residue, which a squeegee or microfiber cloth can handle cleanly.

Tips

• This two-stage approach is mainly for exterior windows or windows near construction, roads, or heavy tree cover
• Skip the pre-wash on lightly soiled interior windows — go straight to vinegar or commercial cleaner