Window cleaning vs. pressure washing

What pressure washing is good at

Removing mildew, algae and grime from concrete, pavers, stucco, pool decks and roofs (with soft-wash chemistry). It's the right tool for those surfaces and most Treasure Coast homes need it once a year or so.

What it does to windows

Forces water past the weatherstripping and into the frame, where it sits and grows mildew or corrodes hardware. Can break the seal on double-pane glass, which means fog between the panes and a replacement unit. Can crack older glass or blow out lanai enclosure panels. And on the glass surface, it leaves mineral spots and streaks because the water dries on the pane instead of being squeegeed off.

Some pressure-washing companies offer window cleaning as an add-on and do it with the same wand at low pressure. That still doesn't squeegee the glass, and it still puts water where it shouldn't go.

What windows actually need

Scrub with a strip washer to lift dirt, squeegee to remove the water and dirt together, detail the edges so nothing drips, wipe the sill. Purified water on exterior glass so any remaining water dries spot-free. That's it, and it's a different skill from pressure washing.

Doing both

If you're having the house pressure washed, schedule window cleaning after it, not before. Pressure washing throws dirt and mildew onto the glass, and a window clean afterward leaves everything finished.