Check the glass and choose a mild method
Check manufacturer guidance for coated, tinted, leaded or otherwise specialised glass, and test any compatible cleaner on a small inconspicuous area. Use a clean applicator and squeegee or lint-free cloth, working from top to bottom and wiping the blade between passes. Avoid abrasive pads and unlabelled mixtures that could damage glass, seals or nearby finishes.
Prepare the area before cleaning
Choose a cool, overcast period where practical; direct heat can dry solution before it is removed. Move objects away from the sill, protect nearby flooring and use only a stable position on the ground or an approved indoor step. Never lean out of a window or improvise ladder access.
Include frames, sills and screens carefully
Remove loose dust first so grit is not dragged across the glass. Clean frames and sills with a method suited to their material, and follow screen-maker instructions before removing or washing mesh. Keep water away from electrical fittings and stop if seals, glazing or frames appear loose or damaged.
Know when to get help
Upper-storey exterior panes, awkward rooflines, damaged glass and persistent mineral deposits can require specialist equipment or assessment. Do not use a scraper, solvent or pressure washer unless the glass maker or a qualified specialist confirms it is suitable. Request a quote with photos and access details when the work is beyond safe reach.
